An annotated checklist of the bees of Washington state

Chanda S. Bartholomew; Elizabeth A. Murray; Silas Bossert; Joel Gardner; Chris Looney

doi:10.3897/jhr.97.129013

Checklist

An annotated checklist of the bees of Washington state

Chanda S. Bartholomew^‡, Elizabeth A. Murray^§|, Silas Bossert^§|, Joel Gardner^§, Chris Looney^‡

‡ Washington State Department of Agriculture, Tumwater, United States of America

§ Washington State University, Pullman, United States of America

| National Museum of Natural History, Washington, DC, United States of America

Corresponding author: Chris Looney ( clooney@agr.wa.gov )

Academic editor: Jack Neff

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation: Bartholomew CS, Murray EA, Bossert S, Gardner J, Looney C (2024) An annotated checklist of the bees of Washington state. Journal of Hymenoptera Research 97: 1007-1121. https://doi.org/10.3897/jhr.97.129013

ZooBank: urn:lsid:zoobank.org:pub:95B34948-7979-418A-B325-215CCB75821F

Abstract

Bees (Hymenoptera: Apoidea) are vital components of global ecosystems, yet knowledge of their distribution is limited in many regions. Washington state is located in an ecologically diverse part of North America and encompasses habitat types and plant communities known for high bee species richness. To establish a baseline for future studies on bee communities in the state, we used published and unpublished datasets to develop a preliminary annotated checklist of bees occurring in Washington state. We document, with high confidence, 565 species of bees in Washington and identify an additional 102 species likely to occur in the state. We anticipate future research survey efforts, such as the newly initiated Washington Bee Atlas, will discover several species that have the potential to occur in Washington and provide new data for 84 species which have not been recorded in more than 50 years.

Keywords

Anthophila, Apoidea, faunal list, new state records, Pacific Northwest, pollinators

Introduction

Despite the global importance of bees and the risk of disrupting vital ecosystem services due to pollinator decline, our basic knowledge of many bee species is still limited (Brown and Paxton 2009; Winfree et al. 2011). Documenting regional bee faunas is essential for monitoring ecosystem health by providing a baseline for understanding changes in species composition at local and regional scales (Winfree et al. 2011; Mathiasson and Rehan 2019; Decker et al. 2020; Kilpatrick et al. 2020). Efforts to fill this gap have resulted in a push to document the bee fauna across the United States, with recent checklists and other biogeographic summaries published for Colorado (Scott et al. 2011), Indiana (Jean 2010), Illinois (Decker et al. 2020), Louisiana (Owens et al. 2018), Maine (Dibble et al. 2017), Massachusetts (Veit et al. 2021), Michigan (Gibbs et al. 2017), Minnesota (Portman et al. 2023), Oregon (Best et al. 2021, 2022), Pennsylvania (Kilpatrick et al. 2020), and Wisconsin (Wolf and Ascher 2009).

Washington state is located in the North American Pacific Northwest, an ecologically diverse region that encompasses wet, coastal forests, geologically active mountains, arid, interior forests, and extensive shrub-steppe plant communities (Franklin and Dyrness 1973). Increased population growth throughout the Puget Sound in the western part of state (Robinson et al. 2005; Zank et al. 2016) and widespread agriculture usage in the eastern part of the state has converted many native ecological communities to heavily modified anthropogenic landscapes (Daubenmire 1970). In fact, Daubenmire’s (1970) efforts to characterize the pre-European vegetation of Washington’s shrub-steppe communities found that most of eastern Washington had already been either heavily grazed by livestock or was already in cultivation after less than 100 years of colonization. The prominence of agriculture in eastern Washington is particularly of concern given that temperate grassland ecosystems are among the most threatened in the world (Lane et al. 2022) and xeric regions such as those east of the Cascade Mountain Range are associated with high bee diversity (Michener 1979; Cane 2011; Orr et al. 2021). For example, the Palouse Prairie in southeastern Washington state and adjacent Idaho is a critically endangered ecosystem, with native plant communities possibly occupying as little 1% of their historic range (Black et al. 1998; Looney and Eigenbrode 2012). Even so, Palouse prairie remnants have been shown to support many rare or endangered species such as ferruginous hawk, white-tailed jackrabbit, and sharp-tailed grouse despite high fragmentation and overall habitat loss (Black et al. 1998; Hanson et al. 2008; Looney and Eigenbrode 2012). Meanwhile, the central xeric regions are historically under-sampled and poorly known compared to the Puget Sound and the Palouse Prairie, despite expecting high bee diversity in such habitats. It is therefore critical to establish a baseline of the species present to assess current regional species richness to inform future state-level conservation planning.

The objective of this checklist is to document the species currently encountered in Washington state, but it is interesting to note that the presence of bees in Washington has also been documented in the fossil record. A fossil of Bombus proavus was discovered during 1927–1928 in the Latah Formation (11.63 Ma to 5.333 Ma) near Spokane in Spokane County (Cockerell 1931), and plant fossils showing possible leaf cutter bee damage were discovered near Republic in Ferry County in the Klondike Mountain Formation (15.97 Ma to 11.63 Ma) (Lewis 1994). Several studies have been made of the bee fauna in parts of Washington, which collectively contribute to a baseline of species presence in the state, but there has yet been no synthesis of these records, or a checklist developed for the state. Contemporary lists perhaps begin with Viereck et al. (1904a; 1904b; 1904c; 1905; 1906) who summarized the known bee species of the Pacific Northwest in a series of five publications, including Washington, Oregon, and British Columbia. This established the first baseline of bee diversity in the region and reported 157 species at the time (although after accounting for synonymies this number drops to 116 species). The next comprehensive bee survey in Washington was not until Tepedino and Griswold (1995) published a technical report on the bees of the Columbia Basin, including parts of Washington, Oregon, and Idaho. They reported 647 species in the Columbia Basin, but emphasize that the area was under-sampled and estimate the actual number of species to be closer to 1000. Mayer et al. (2000) reported 72 species in a small area near the Snake River in southeastern Washington, although this did not include any Lasioglossum identified to species. Wilson et al. (2010) surveyed bees in the Tonasket Ranger District of Okanogan-Wenatchee National Forest (in north-central Washington), reporting 140 species. Hatten et al. (2013) published a list of the Bombus of the Palouse Prairie (including parts of Washington and Idaho) based on bycatch from pitfall traps and identifying ten species. Subsequent work by Rhoades et al. (2017) in the same areas resulted in a more comprehensive sample of the Palouse bee taxa, reporting 174 identified species and 36 undetermined morphospecies, 57 of which were new to the Palouse.

To obtain a baseline bee fauna of Washington state, data from these disparate studies and other literature records must first be compiled. Examination of museum specimens and collection of fresh material is also needed, especially in areas that are not previously well-studied. The objective of this checklist is to provide such a baseline for the state of Washington for use by the public, policymakers, and researchers to guide future research and conservation plans.

Materials and methods

The checklist was compiled using online biodiversity database portals [Global Biodiversity Information Facility (GBIF; gbif.org) and Discover Life Global Mapper (discoverlife.org; Ascher and Pickering 2022)], specimens in private and institutional collections, and literature review. GBIF records were searched by selecting a coordinate polygon to include only Washington records (GBIF 2022a). Because not all Washington records have explicit geocoordinates associated with them, a second search was conducted using Washington as the state location (GBIF 2022b). Online records accessed by GBIF and Discover Life Global Mapper were obtained from various museum collections and the Barcode of Life Data System (BOLD; boldsystems.org; Ratnasingham and Hebert 2007) as well as citizen or community science records from citizen or community science portals iNaturalist, Bumble Bee Watch, and BugGuide. Table 1 presents a list of all private or institutional collections used to compile this checklist, accessed through GBIF, the Discover Life Global Mapper, or personal communications.

Table 1.

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List of collections and databases holding species records.

AMNH	American Museum of Natural History, New York, NY
BugGuide	BugGuide (bugguide.net)
OSUC	C. A. Triplehorn Insect Collection, Ohio State University, Columbus, OH
CAS	California Academy of Sciences, San Francisco, CA
CSCA	California State Collection of Arthropods, California Department of Food and Agriculture, Sacramento, CA
CMNH	Cleveland Museum of Natural History, Cleveland, OH
CNC	Canadian National Collection of Insects, Arachnids, and Nematodes, Agriculture Canada, Ottawa, Ontario, Canada
CUIC	Cornell University Insect Collection, Ithaca, NY
FMNH	Field Museum of Natural History, Chicago, IL
PSUC	Frost Entomological Museum, Penn State University, State College, PA
NMDG	Nate Green’s Private Collection
INHS	Illinois Natural History Survey, University of Illinois, Champaign, IL
iNaturalist	iNaturalist (inaturalist.org)
JRYA	Jessica Rykken’s Database
LACM	Los Angeles County Museum, Los Angeles, CA
Miliczky	Miliczky’s Private Collection
MCZ	Museum of Comparative Zoology, Harvard University, Cambridge, MA
TTU	Museum of Texas Tech University, Lubbock, TX
UMNH	Natural History Museum of Utah, Salt Lake City, UT
NMNH	National Museum of Natural History, Smithsonian Institution, Washington, D.C. (formerly USNM, United States National Museum)
NMSU	New Mexico State Collection of Arthropods, Las Cruces, NM
NYSM	New York State Museum, Albany, NY
NCSU	North Carolina State University Insect Museum, Raleigh, NC
PCYU	Packer Collection, York University, Toronto, Ontario, Canada
PWRC	Patuxent Wildlife Research Center, US Geological Survey, Laurel, MD
ANSP	Philadelphia Academy of Natural Sciences, Philadelphia, PA
BBSL	Pollinating Insect – Biology, Management, Systematics Research Unit, Logan, UT
RSKM	Royal Saskatchewan Museum, Regina, Saskatchewan, Canada
RUAC	Rutgers University Entomological Museum, New Brunswick, NJ
TAMU	Texas A&M University Insect Collection, College Station, TX
Hanson	Thor Hanson’s Private Collection
UCDC	University of California, Bohart Museum of Entomology, Davis, CA
EMEC	University of California, Essig Museum of Entomology, Berkeley, CA
UCRC	University of California, Riverside, CA
UCMC	University of Colorado Museum of Natural History, Boulder, CO
UCMS	University of Connecticut Insect Collection, Storrs, CT
SEMC	University of Kansas, Snow Entomological Museum Collection, Lawrence, KS
UNSM	University of Nebraska-Lincoln State Museum, Morrill Hall, Lincoln, NE
UNHC	University of New Hampshire Collection of Insects and Arthropods, Durham, NH
UNM	University of New Mexico, Museum of Southwestern Biology, Division of Arthropods, Albuquerque, NM
FWSE	U.S. Fish and Wildlife Service, Vancouver, WA
WFBM	University of Idaho, W. F. Barr Entomological Collection, Moscow, ID
WSDA	Washington State Department of Agriculture, Tumwater, WA
WSUC	Washington State University, M. T. James Entomological Collection, Pullman, WA
WWUC	Western Washington University Insect Collection, Bellingham, WA
BOMBUS	Xerces Society – Bumble Bee Watch
PMNH	Yale University, Peabody Museum of Natural History, New Haven, CT

Data quality of records accessed through online biodiversity database portals such as GBIF and Discover Life Global Mapper can be inconsistent (Goodwin et al. 2015; Gibbs et al. 2017). Similarly, it is important to evaluate the accuracy of data collected from community science programs such as Bumble Bee Watch and BugGuide to determine their appropriate use (MacPhail et al. 2020). To ensure that this checklist is reasonably accurate, records were filtered to only include records from collections currently or previously managed by known bee experts, and community science submissions that were confirmed by known bee experts. Nonetheless, this contribution must be regarded as a preliminary checklist, as we were not able to verify every single record, and several entries warrant reassessment.

Literature sources were reviewed for any bees recorded from Washington. Not all such records include collection dates or locality data. Where possible, some of this information was inferred from the methods section. Records without county were georeferenced using the USGS Domestic Names Database (https://edits.nationalmap.gov/apps/gaz-domestic/public/search/names). If the location could not be found by searching in the USGS domestic names database, we used other historical documents (e.g. antique maps) to identify the location in the state and then manually locate it on a map.

Species names are updated to match current taxonomy. Taxonomy generally follows the Integrated Taxonomic Information System (itis.gov) and Michener (2007), with the following exceptions: the higher-level classification of Apidae follows Bossert et al. (2019; 2020); the generic classification of Eucerini follows Freitas et al. (2023); the taxonomy for Bombus follows Williams (1998; and the regularly updated website Bombus: bumblebees of the world), Williams et al. (2014), Williams et al. (2015), Martinet et al. (2019), Ghisbain et al. (2020), and Lhomme et al. (2021); Epeolus follows Onuferko (2017); Nomada follows Droege et al. (2010), and Brachymelecta follows Onuferko et al. (2021). The Andrena subgenera classification follows Pisanty et al. (2022).

We based much of the structure and format of this list on the updated checklist of Pennsylvanian bees (Kilpatrick et al. 2020). The Washington checklist is organized alphabetically by family with each subsequent level (i.e., subfamily, tribe, genus, subgenus, and species) also organized alphabetically. Records for each species include, if available, the county where it was recorded, each month it was recorded as well as the most recent year it was recorded (in parentheses), the collection where specimens can be found, conservation status, and any floral and host associations noted in the literature and specific to Washington. Records of subspecies are kept in the checklist as they were identified, but were only considered at the species level for purposes of calculating species richness. In some cases, the same records appear in multiple databases or literature sources (e.g. the same specimens may be referred to in a revision and again in a subsequent summary). Since this list is not quantitative at the species level, we did not attempt to address the “first” appearance per se or otherwise parse these duplicative instances, instead opting to report each dataset. Records that were not previously published in a peer-reviewed journal are treated as new state records and/or county records. A denotation of state record does not mean that we discovered the species through our own efforts, but rather that we highlight a digital record or database entry that we deem reliable, or that we present newly digitized information from the Washington State University M. T. James Entomological Collection (WSUC). Newly reported state records are denoted by a dagger symbol (†). Counties are listed in bold to denote new county records. We considered any species with a likely native range that does not include Washington state (e.g. species from Europe or known only from the eastern United States) to be introduced and denote them with an asterisk (*).

When available conservation status was assessed using the International Union for Conservation of Nature (IUCN), NatureServe, and the Xerces Society Red List of Pollinating Insects of North America. Species categorized as critically endangered may have an extremely high risk of extinction, while species categorized as vulnerable may have a high risk of extinction. Species categorized as least concern do not meet the criteria for other categories and are generally not the target of conservation action. Species missing data critical for the determination of its conservation status are categorized as data deficient. A more detailed description of the criteria determining each category can be found in IUCN Red List Categories and Criteria: Version 3.1 (IUCN 2001). NatureServe assesses and assigns ranks for species and ecosystems at the global (G1 – G5) and state levels (S1 – S5) (NatureServe 2024). Ranks range from critically endangered (G1 and S1) to secure (G5 and S5). A more detailed description of how NatureServe assigns conservation status can be found at https://www.natureserve.org/conservation-status-assessment (NatureServe 2024).

Some records were for species far outside of their known and expected range, with no known specimens or other information available to verify their accuracy. While these data contribute to an accurate account of species recorded in Washington, they could represent identification or labelling errors and seem less likely to occur in the state. Because this list may be used to inform conservation and research decisions, we placed such questionable records in a separate section to ensure that they are readily identifiable as unverified and caution readers to consider them in this context.

Expected species were determined from reviewing published species distribution maps that included Washington. Species with an expected distribution in Washington but no known records were highlighted as likely to occur in Washington. Additionally, species occurring near Washington in Oregon, Idaho, and/or British Columbia in habitats similar to those within Washington or with host plants occurring within Washington were also considered to likely occur in Washington. By these criteria, at least 120 additional species of bees are likely to occur in Washington. However, many specimens in museum collections await identification or formal description (Orr et al. 2021) and thus some of these species may already have been collected in the state. Currently undescribed species would add to this total expected species.

Additionally, an interactive map with county-level data and the option to map bee records by family is available online (https://phylosolving.shinyapps.io/WA_bee_catalog/) as a shiny app (Chang et al. 2024), which was created using leaflet (Cheng et al. 2024) in R (R Core Team 2023). The dataset is associated with this paper and is not intended to be updated; instead, these data and new records generated by the Washington Bee Atlas or other research will be migrated to a “living” interface that is currently being developed.

Results and discussion

Using these data, we record 565 described species of bees in Washington State, representing 44 genera from all 6 families of bees known from North America (Table 2). The remaining bee family, Stenotritidae, is known only from Australia. We found records or data for 603 potential bee species in Washington state but removed 38 questionable records. Andrena, with 109 species, had the highest species richness of any genus in Washington state, comprising 20% of the total species. This is not surprising, as Andrena is known to be species rich in temperate bee communities of North America (e.g., Kilpatrick et al. 2020; Rhoades et al. 2018). As an example, 12% of the observed species in a survey of just montane areas of north-central Washington were Andrena (Wilson et al. 2010; Rhoades et al. 2018).

Table 2.

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Bee species recorded from Washington state, not including questionable records. The number of introduced species is indicated in parentheses.

Andrenidae	Andrena	109 (1)	Halictidae	Agapostemon	3
	Calliopsis	4		Dufourea	5
	Panurginus	3		Halictus	6
	Perdita	9		Lasioglossum	63 (4)
	Total	124 (1)		Nomia	1
				Sphecodes	8
				Total	84 (4)
Apidae	Anthophora	15	Megachilidae	Anthidiellum	2
	Apis	1 (1)		Anthidium	11 (2)
	Bombus	25 (1)		Ashmeadiella	8
	Brachymelecta	1		Atoposmia	2
	Ceratina	5		Chelostoma	2
	Diadasia	6		Coelioxys	8
	Epeolus	6		Dianthidium	7
	Epimelissodes	1		Dioxys	4
	Eucera	10		Heriades	4
	Habropoda	4		Hoplitis	12
	Melecta	3		Megachile	31 (3)
	Melissodes	23		Osmia	70 (2)
	Nomada	35		Protosmia	1
	Oreopasites	1		Stelis	15
	Triepeolus	8		Total	177 (7)
	Xylocopa	1(1)
	Zacosmia	1
	Total	150 (3)
Colletidae	Colletes	14	Melittidae	Macropis	1
	Hylaeus	16 (2)		Total	1
	Total	30 (2)		Total	1

Ground nesting species frequently outnumber other bee groups in regional bee faunas (Cane 2008), and Washington’s fauna is no exception (Fig. 1; see Suppl. material 1 for all the life history data for each species). Most Washington bees with known or presumed ecological data are ground nesting (254 species), followed by cavity nesting species (180 species). Some Megachile species are known to nest in cavities in the ground as well as excavate nests in the ground (Michener 2007). The literature is not always clear on this point, and some of these species may actually be cavity nesting instead of ground nesting and vice versa. Washington’s bee fauna is primarily solitary (380 species) as are most species globally (Danforth et al. 2019), followed by cleptoparasites (90 species), social species (33 species), and social parasites (4 species). Floral preference is unknown for many of Washington’s bees. However, for those with known floral preference data, Washington’s bee fauna appears to be more polylectic (163 species) than oligolectic (110 species). Notable among the solitary ground nesting species found in Washington is the alkali bee, Nomia melanderi Cockerell, which is of considerable agricultural importance as an alfalfa pollinator (Cane 2008). Known for being the only managed solitary ground-nesting species of bee in the world, large aggregations of N. melanderi can be found in Walla Walla County where nesting beds consisting of moist silty and periodically salted soils have been maintained and protected for decades (Cane 2008; Kapheim et al. 2021; Cane 2024), including reduced local speed limits to minimize mortality (Vinchesi 2014). Other notable native Washington solitary bees include the mason bees Osmia aglaia Sandhouse, O. atriventris Cresson, and O. lignaria Say, all of which are important raspberry pollinators (Drummond and Stubbs 1997; Andrikopoulos and Cane 2018).

Figure 1.

Total number of Washington bees with known ecological data by lifestyle, nesting preference, and floral preference.

The peak of bee activity in Washington statewide is between April and September with Megachilidae being the most species rich during this period (Fig. 2a). However, some species of Andrenidae, Apidae, and Megachilidae are active throughout the year. When comparing the seasonality geographically, Andrenidae has a higher peak in the spring on the west side of the Cascades indicating that the west side has more species of spring flying Andrenidae than the east side (Fig. 2b, c). Also, the Apidae peak earlier in the season on the west side than the east side. Different bee taxa vary in their seasonality (Oglivie and Forrest 2017). Andrena, except the subgenera Callandrena and Cnemidandrena, are mostly early spring species (LaBerge 1986b; Larkin et al. 2008; Oglivie and Forrest 2017). Most Osmia (Megachilidae) are also spring species; in contrast, Megachile spp. tend to be more active in the late summer (Oglivie and Forrest 2017).

Figure 2.

Seasonality of Washington bee species by family for A Washington state B east of the Cascade Mountains, and C west of the Cascade Mountains, based on collection or observation dates from records reviewed for this checklist.

Most of Washington is under sampled for bees (Figs 3, 4). The number of species by county almost certainly reflects which parts of the state have been more heavily sampled than others, rather than the actual species richness of that county (Fig. 5). Counties with more than 100 documented species (e.g., Benton, Chelan, King, Kittitas, Klickitat, Okanogan, Pierce, Spokane, Thurston, Walla Walla, Whitman, and Yakima Counties) are also home to Washington’s largest cities and/or popular recreational areas and are more likely to have documented citizen or community scientist records. In addition, some of these same counties (e.g., Okanogan and Whitman Counties) were locations of research projects targeting bee biodiversity.

Figure 3.

Map of the records for all families, excluding Apis mellifera and Bombus spp. This map was built in QGIS using a Level IV Shapefile from EPA as a basemap.

Figure 4.

Map of the records for Apis mellifera and Bombus spp. This map was built in QGIS using a Level IV Shapefile from EPA as a basemap.

Figure 5.

Bee species richness for each of the 39 counties of Washington. Whitman county in eastern Washington has the most recorded species (288), while Wahkiakum in western Washington has the least (16). This interactive map with additional county-level data and the option to filter records by family is available at: https://phylosolving.shinyapps.io/WA_bee_catalog/. This map was built in Leaflet (http://agafonkin.com/en/) using tiles from USGS.

Washington is an ecologically diverse state, with the Cascade Mountains separating the western coastal forests from the arid interior forests and shrub-steppe to the east (Franklin and Dyrness 1973). According to EPA’s Level III and IV Ecoregions of Washington map, the state has nine Level III ecoregions and 57 Level IV ecoregions (US Environmental Protection Agency 2012). The Columbia Plateau, located east of the Cascade Mountains, has the highest richness of bee species (Table 3; see Suppl. material 2 for species by ecoregion). Additionally, nine of the 44 genera in this dataset have been recorded from only east of the Cascade Mountains (Fig. 6), although some of these will likely be detected in western Washington in future surveys. Even so, we expect that some genera are indeed restricted to eastern Washington. For example, Zacosmia is a genus of cleptoparasites whose hosts (Anthophora (Micranthophora)) are associated with xeric or semi-xeric habitats (Michener 2007; Orr et al. 2018). No genus was recorded from only the west side of the state in the records we reviewed. Orr et al. (2021) found bee species richness was greatest in regions characterized by high solar insolation, high average potential evapotranspiration, low precipitation during the driest month, and decreased seasonal variation. Additionally, tree presence negatively impacted bee richness (Orr et al. 2021). As the Columbia Plateau meets these conditions, it is unsurprising that there is more species richness as well as more unique species in this ecoregion compared to the ecoregions west of the Cascade Mountains, where there are more trees and precipitation.

Figure 6.

Map of the genera only recorded on the east side of the Cascade Mountains. This map was built in QGIS using a Level IV Shapefile from EPA as a basemap.

Table 3.

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The number of bee species recorded in each EPA Level III Ecoregion.

EPA Level III Ecoregion	Number of Species
Blue Mountains	32
Cascades	74
Coast Range	66
Columbia Plateau	399
Eastern Cascades Slopes and Foothills	157
North Cascades	160
Northern Rockies	139
Puget Lowlands	213
Willamette Valley	35

Eighty-four species (15%) on this list have not been documented in the state since before 1970, with more than 80% of these from eastern Washington. More than a quarter of these species are cleptoparasites. In fact, nearly half of the recorded species of the cleptoparasitic genus Nomada haven’t been reported in decades. Of the 84 species not documented in over 50 years, 16 are only known from their type specimens, 10 of which are cleptoparasites. Notable among these 16 species is the Lysimachia (loosestrife) specialist Macropis steironematis opaca, the single representative of Melittidae in Washington state. This species has not been sighted since 1882 when it was collected from Morgan’s Ferry along the Yakima River, despite focused survey efforts in recent decades. Macropis are ecologically unusual in that they collect floral oils from Lysimachia spp. for nest provisioning as well as for lining nest cell walls (Cane et al. 1983; Michez and Patiny 2005; Packer 2023).

Of the 158 bee species with a federally and/or state determined conservation status, Washington has 42 bee species that have been determined to have a conservation status of vulnerable, imperiled or critically imperiled or endangered by organizations such as IUCN, the Xerces Society, and NatureServe (Table 4). Included are the following six species which have not been documented in the state in more than 50 years: Andrena aculeata, Perdita similis pascoensis, Megachile legalis, Osmia lanei, O. nigrobarbata, and Macropis steironematis opaca. Currently, the Washington Department of Fish and Wildlife State Wildlife Action Plan only identifies Bombus morrisoni, B. occidentalis, and B. suckleyi as species of greatest conservation need (SGCN) (Washington Department of Fish and Wildlife 2015). Future research should focus on determining the conservation needs of the remaining 39 species of possible conservation concern as well as the 407 species without conservation status determination. Nesting and floral resources are such vital components of bee survival, yet this data is lacking for so many species making it difficult to assess conservation statuses (Orr et al. 2022).

Table 4.

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Species with conservation statuses of possible conservation concern. CE = critically endangered and Vul = vulnerable (National Research Council); G2 = imperiled, G3 = vulnerable, S1 = critically imperiled, S2 = imperiled, S3 = vulnerable (NatureServe 2024).

Family	Species	CE	Vul	G2	G3	S1	S2	S3
Andrenidae	Andrena aculeata		X
	Perdita similis pascoensis		X
	Perdita wyomingensis sculleni		X
Apidae	Anthophora crotchii				X
	Anthophora neglecta				X
	Anthophora occidentalis				X
	Bombus appositus				X
	Bombus caliginosus		X	X				X
	Bombus fervidus complex		X		X
	Bombus flavidus							X
	Bombus frigidus						X
	Bombus insularis				X
	Bombus kirbiellus					X
	Bombus lapponicus sylvicola							X
	Bombus morrisoni		X		X
	Bombus occidentalis		X		X		X
	Bombus suckleyi	X		X		X
	Bombus vagans						X
	Bombus vandykei							X
	Eucera douglasiana		X
	Eucera frater lata		X
	Habropoda miserabilis			X
Megachilidae	Anthidium banningense				X
	Anthidium edwardsii				X
	Hoplitis orthognatha		X
	Hoplitis producta subgracilis		X
	Megachile anograe				X
	Megachile dentitarsus				X
	Megachile legalis				X
	Megachile nevadensis				X
	Megachile snowi				X
	Megachile umatillensis				X
	Osmia austromaritima				X
	Osmia iridis				X
	Osmia lanei				X*
	Osmia nigrobarbata				X
	Osmia obliqua				X
	Osmia odontogaster			X
	Osmia pulsatillae			X
	Osmia thysanisca				X
	Osmia trifoliama				X*
Melittidae	Macropis steironematis opaca	X

The bee fauna of Washington state is more species rich than its northern neighbor British Columbia, which has 483 documented species (Sheffield and Heron 2018). Future studies of Washington’s more under-surveyed counties, such as Adams, Douglas, Franklin, Grant, and Lincoln in the Columbia Plateau as well as the 22 other counties with fewer than 100 documented species (Fig. 5), will add to this documented richness. Based on recent records of bees from adjacent states and British Columbia, we anticipate at least another 102 species are likely to be recorded in Washington state making the species richness more comparable to the nearly 700 species expected to occur in Oregon (Best et al. 2022). Future efforts should also target the 84 species that have not been documented in over 50 years. It is likely many of these species have been undetected over time due to characteristics that make them inherently uncommon such as limited distributions, floral specialization, cleptoparasitic habits, or difficulty in identification (Colla et al. 2012). There are also many specimens in museum and private collections that, due to various reasons, are still waiting for identification or for formal species descriptions (Orr et al. 2021). As museums work towards digitizing their collections, some of these long-absent species may be rediscovered and new species may be detected or even described. Cleptoparasitic bee species have been found to be good indicator taxa for assessing bee communities (Sheffield et al. 2013a, 2013b), so determining the status of these missing cleptoparasitic species will help future assessments of the bee community health in Washington state.

Checklist

Sources used to compile this checklist: ¹GBIF (polygon); ²GBIF (without coordinates); ³Ascher and Pickering 2022 (Discover Life); ⁴Ratnasingham and Hebert 2007 (BOLD); ⁵Hanson Collection; ⁶WSDA; ⁷WSUC; ⁸Mayer et al. 2000; ⁹Rozen 1992; ¹⁰Fabian 2014; ¹¹LaBerge 1980; ¹²LaBerge 1973; ¹³LaBerge 1989; ¹⁴LaBerge and Ribble 1975; ¹⁵LaBerge 1986a; ¹⁶LaBerge 1985; ¹⁷LaBerge 1977; ¹⁸Bouseman and LaBerge 1978; ¹⁹LaBerge 1969; ²⁰LaBerge and Ribble 1972; ²¹LaBerge and Bouseman 1970; ²²Hanson and Ascher 2018; ²³Miliczky 2008; ²⁴Mitchell 1935a; ²⁵Mitchell 1937a; ²⁶Mitchell 1937b; ²⁷Mitchell 1935b; ²⁸Mitchell 1937c; ²⁹Mitchell 1936a; ³⁰Mitchell 1936b; ³¹Rightmyer et al. 2010; ³²Rhoades et al. 2017; ³³Looney et al. 2019; ³⁴Michener 1935; ³⁵Linsley 1939; ³⁶Adlakha 1969; ³⁷Stephen 1952; ³⁸Gibbs 2010; ³⁹Roberts 1973; ⁴⁰Sinha and Michener 1958; ⁴¹Gonzalez and Griswold 2013; ⁴²Michener 1938a; ⁴³Michener 1938b; ⁴⁴Michener 1939; ⁴⁵Michener 1938c; ⁴⁶Clement et al. 2006; ⁴⁷Koch et al. 2017; ⁴⁸Timberlake 1971; ⁴⁹LaBerge 1961; ⁵⁰Cockerell 1906a; ⁵¹Cockerell 1911; ⁵²Cockerell 1904; ⁵³Timberlake 1943; ⁵⁴Timberlake 1951; ⁵⁵Snelling 1970; ⁵⁶Gibbs 2011; ⁵⁷McGinley 2003; ⁵⁸Daly 1973; ⁵⁹Wilson et al. 2010; ⁶⁰Ribble 1974; ⁶¹Thompson and Pellmyr 1992; ⁶²Thorp 1969; ⁶³Ribble 1968; ⁶⁴Onuferko and Sheffield 2022; ⁶⁵Droege et al. 2010; ⁶⁶Timberlake 1958; ⁶⁷Timberlake 1968; ⁶⁸Ghisbain et al. 2020; ⁶⁹Koch et al. 2016; ⁷⁰Strange and Tripodi 2019; ⁷¹Shapiro et al. 2014; ⁷²LaBerge 1956a; ⁷³Onuferko 2017; ⁷⁴Onuferko 2018; ⁷⁵Rightmyer 2008; ⁷⁶Cockerell 1910; ⁷⁷Rodeck 1947; ⁷⁸Cane 2008; ⁷⁹Gardner and Gibbs 2020; ⁸⁰Gibbs et al. 2013; ⁸¹McGinley 1986; ⁸²Bohart 1948; ⁸³Snelling 1966; ⁸⁴Stephen 1954; ⁸⁵Donovan 1977; ⁸⁶Thorp and LaBerge 2005; ⁸⁷Crawford 1926; ⁸⁸Timberlake 1956; ⁸⁹Timberlake 1964; ⁹⁰Baker 1975; ⁹¹Grigarick and Stange 1968; ⁹²Mitchell 1944; ⁹³Raw 2002; ⁹⁴Mitchell 1942; ⁹⁵Mitchell 1927; ⁹⁶Hurd and Michener 1955; ⁹⁷Michener 1936a; ⁹⁸Swenk 1914; ⁹⁹Mitchell 1933; ¹⁰⁰Sandhouse 1939; ¹⁰¹White 1952; ¹⁰²Griswold 1983; ¹⁰³Michener 1947; ¹⁰⁴Rowe 2017; ¹⁰⁵Thorp et al. 1983; ¹⁰⁶Brooks 1983; ¹⁰⁷Orr et al. 2018; ¹⁰⁸LaBerge 1956b; ¹⁰⁹Timberlake 1969; ¹¹⁰Broemeling 1988; ¹¹¹Rodeck 1949; ¹¹²Tepedino and Griswold 1995; ¹¹³Viereck 1916; ¹¹⁴Cockerell 1937; ¹¹⁵Viereck et al. 1904a; ¹¹⁶Viereck et al. 1904b; ¹¹⁷Viereck et al. 1904c; ¹¹⁸Viereck et al. 1905; ¹¹⁹Viereck et al. 1906; ¹²⁰Cockerell 1903; ¹²¹Cockerell 1906b; ¹²²Gardner and Gibbs 2023; ¹²³Rozen 1958; ¹²⁴National Park Service (personal communication); ¹²⁵Michener 1936b; ¹²⁶Swenk 1908; ¹²⁷Cockerell 1913; ¹²⁸Akre et al. 1982; ¹²⁹Cockerell 1912; ¹³⁰Taylor 2008; ¹³¹Mitchell 1938; ¹³²Zack 1984; ¹³³Waters 2023; ¹³⁴Miliczky 2000; ¹³⁵Green Collection; ¹³⁶Combs 2019

† State record

* Introduced

§ Species of possible conservation concern

‡ Most recent record before 1970

Andrenidae: Andreninae: Andrenini

Genus Andrena Fabricius

1. §‡ Andrena (Andrena) aculeata LaBerge, 1980. County records: Whitman¹¹. Seasonality: May¹¹ (1913¹¹). Conservation status: Vulnerable (Shepherd 2005a, National Research Council 2007)

2. ‡ Andrena (Andrena) birtwelli Cockerell, 1901. County records: Kittitas^1,2,11. Seasonality: Jul^1,2 (1949^1,2). Collections: SEMC

3. Andrena (Andrena) buckelli Viereck, 1924. County records: Garfield^1,2,3,46, Kittitas^1,2,11, Whitman^7,11. Seasonality: May^1,2,3, Jun^7,46, Jul^1,2 (1989^1,2,3). Collections: BBSL, SEMC, WSUC. Floral records: FABACEAE: Astragalus sp.³

4. Andrena (Andrena) ceanothifloris cretata LaBerge, 1980. County records: Okanogan^1,2,3,59. Seasonality: Jul^1,2,3 (2004^1,2,3,59). Collections: BBSL. Floral records: ERICACEAE: Ledum glandulosum^3,59

5. Andrena (Andrena) frigida Smith, 1853. County records: King^1,2,3,11,117, Kitsap^2,3,11, Pend Oreille^3,11, Pierce^3,11, Snohomish^3,11, Walla Walla³, Whitman^3,11,117, Yakima^3,11. Seasonality: Feb¹¹⁷, Mar^1,2,3,117, Apr^2,3, Jul² (1996^1,2). Collections: INHS, NYSM, UNHC, UCRC, WSUC. [= Cilissa albihirta Ashmead, 1890]

6. Andrena (Andrena) hemileuca Viereck, 1904. County records: Ferry^3,11, Island⁷, King^{1,2,3,7,11,117}, Kitsap^3,11, Lewis⁷, Pierce^3,11, Skagit¹⁰, Snohomish^1,2,3, Thurston¹³³, Whitman^3,11,117. Seasonality: Apr⁷, May^1,2,3,7,133 (2017¹³³). Collections: ANSP, INHS, NMNH, SEMC, WSUC, WWUC. Holotype. USA, Washington Territory; PANS 10286. [= Andrena (Andrena) asmi Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman; C. V. Piper. Floral records: ASPARAGACEAE: Camassia quamash¹³³; ROSACEAE: Sorbus scopulina⁸.

7. ‡ Andrena (Andrena) jennei Viereck, 1916. County records: Yakima^1,2,3,113. Seasonality: May^1,2,113 (1903^1,2,113). Collections: ANSP. Holotype. USA, Washington, Yakima County, North Yakima; 20 May 1903; Eldred Jenne; No. 60, ANSP 4013

8. † Andrena (Andrena) laminibucca Viereck and Cockerell, 1914. County records: Jefferson^1,2, Kittitas^2,3. Seasonality: May^2,3, Jun^1,2 (2014^1,2). Collections: BBSL, INHS

9. † Andrena (Andrena) macoupinensis Robertson, 1900. County records: Benton^2,3,7, Kittitas^2,3, Yakima^2,3, Whitman⁷. Seasonality: Apr^2,3,7 (1989^2,3). Collections: INHS, WSUC

10. Andrena (Andrena) milwaukeensis Graenicher, 1903. County records: Chelan^1,2, Kittitas⁷, Klickitat^1,2, Lewis^1,2,4, Spokane^1,2,7, Thurston¹³³. Seasonality: Apr^1,2, May^1,2,4, June¹³³ (2019¹³³). Collections: BBSL, RSKM, WSUC. Floral records: FABACEAE: Lupinus albicaulis¹³³

11. Andrena (Andrena) perarmata Cockerell, 1898. County records: King^1,2,3,11, Kitsap^2,3, Kittitas^2,3, Pierce^3,11, Thurston^3,7,11, Walla Walla^1,2,3, Whitman^7,8, Yakima^3,11. Seasonality: Feb^1,2, Mar^1,2,3,7,11, Apr^1,2,3 (1989^2,3). Collections: BBSL, INHS, NMNH, WSUC. Holotype. USA, Washington, King County, Seattle; 15 March 1897; USNM 18982, USNM ENT 00533688. Floral records: APIACEAE: Lomatium⁸

12. ‡ Andrena (Andrena) prolixa LaBerge, 1980. County records: Pierce^1,2,3,11. Seasonality: Apr^1,2,11 (1945^1,2,11). Collections: INHS

13. Andrena (Andrena) rufosignata Cockerell, 1902. County records: Clallam^1,2,3,11, King^1,3,11, Okanogan^1,2,3,59, Pierce^3,11, Thurston¹³³, Whatcom^1,2. Seasonality: May^1,2,133, Jun^1,2,3,133, Jul^1,2,3 (2020¹³³). Collections: BBSL, INHS, OSUC, SEMC. Floral records: APIACEAE: Lomatium pugetensis¹³³; ASPARAGACEAE: Camassia quamash¹³³; BORAGINACEAE: Myosotis laxa⁵⁹; CAPRIFOLIACEAE: Symphoricarpos albus¹³³; ERICACEAE: Phyllodoce empetriformis^3,59; OROBANCHAECEAE: Pedicularis bracteosa var. latifolia⁵⁹; ROSACEAE: Potentilla gracilis¹³³

14. Andrena (Andrena) saccata Viereck, 1904. County records: Clallam^1,2,3,11, Grays Harbor^3,11, King^1,2,3,11,117, Pacific^3,11, Pierce^1,2,3, Snohomish^2,3, Walla Walla^1,2,3. Seasonality: Apr¹¹⁷, May^1,2, Jun^1,2,3, Jul^1,2,3, Aug^2,3 (1975^1,2,3). Collections: BBSL, INHS, OSUC

15. † Andrena (Andrena) schuhi LaBerge, 1980. County records: Spokane^1,2, Whitman^1,2,3,7. Seasonality: Mar^1,2, Apr⁷, May^1,2,7 (2011^1,2). Collections: BBSL, SEMC, WSUC

16. Andrena (Andrena) thaspii Graenicher, 1903. County records: Chelan^3,11, Clallam^3,11, Columbia^1,2,3,11, Garfield¹¹, Island¹¹, Jefferson^1,2,3,11, King^1,2,3,11, Kittitas^2,3, Pierce¹¹, San Juan¹¹, Skagit^1,2,3,11, Snohomish^2,3, Thurston^{1,2,3,11,117,133}, Whitman^3,11, Yakima^3,11. Seasonality: Jun^{1,2,3,117,133}, Jul^1,2,3, Aug^2,3 (2020¹³³). Collections: AMNH, ANSP, BBSL, INHS, NMNH. [= Andrena clypeoporaria Viereck, 1904]. Holotype. USA, Washington, Thurston County, Olympia; 12 June 1895; PANS 10290. [= Andrena indotata Viereck, 1904]. Holotype. USA, Washington State; PANS 10295. Floral records: CAPRIFOLIACEAE: Symphoricarpos albus¹³³; FABACEAE: Lupinus albicaulis¹³³

17. Andrena (Andrena) topazana Cockerell, 1906. County records: Asotin^3,11, Columbia^3,11, Okanogan^1,2,3,59, Walla Walla^1,2,3, Whitman⁷. Seasonality: Jun^1,2,3, Jul^1,2,7, Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL, WSUC. Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Cirsium arvense⁸; ROSACEAE: Potentilla gracilis⁵⁹, Rosa nutkana ssp. nutkana^3,59

18. Andrena (Andrena) vicinoides Viereck, 1904. County records: Asotin^3,11, Clallam^3,11, Island⁷, King^3,11, Kitsap^3,7,11, Okanogan^1,2,3,59, Pacific^3,11, Pierce^3,7,11, San Juan^{1,2,11,124,136}, Skagit^1,2,3,11,124, Thurston^3,11,117, Whitman^3,11. Seasonality: May^1,2,7, Jun^1,2,3,117, Jul^1,2,3,7 (2017¹³⁶). Collections: BBSL, PWRC, WSUC. Floral records: FABACEAE: Lupinus sericeus⁵⁹; ROSACEAE: Potentilla gracilis⁵⁹, Rosa nutkana¹³⁶

19. Andrena (Andrena) washingtoni Cockerell, 1901. County records: Clallam³, Douglas^1,2,3, King^3,11,117, Pierce^1,2,3,11, Skamania^3,11, Thurston^1,3,11,117. Seasonality: Apr¹¹⁷, May^1,2,3,117, Jun^1,3,11,117, Jul³ (2014³). Collections: BBSL, INHS, JRYA, NMNH. Holotype. USA, Washington, Thurston County, Olympia; 2 June 1895; Type No. 18938, USNM ENT 00533758

20. ‡ Andrena (Callandrena sensu lato) helianthi Robertson, 1891. County records: Whitman⁸. Seasonality: (1962–1963⁸). Collections: WSUC. Floral records: ASTERACEAE: Helianthus annuus⁸, Solidago canadensis⁸. Comments: Phylogenetic analyses (Larkin et al. 2006; Pisanty et al. 2021) have found the subgenus Callandrena to be paraphyletic. Callandrena in its strict sense was found to be monophyletic (Larkin et al. 2006; Pisanty et al. 2021). The remaining species, including A. helianthi, belong to another separate unnamed group that is sometimes referred to as Callandrena sensu lato.

21. † Andrena (Cnemidandrena) colletina Cockerell, 1906. County records: Klickitat^2,3. Seasonality: Sep^2,3 (1989^2,3). Collections: INHS

22. Andrena (Cnemidandrena) columbiana Viereck, 1917. County records: Benton⁷, Clallam³, Island^3,85, Jefferson^1,2, King^3,85, Okanogan^1,2,3,59, Pacific^1,2,3,85, Pend Oreille^3,85, San Juan^3,85, Snohomish^2,3, Thurston⁷, Whatcom^3,85, Yakima^3,85. Seasonality: May^1,2, Jun^1,2,85, Jul^1,2,85, Aug^1,2,3,85 (2015^1,2,3). Collections: BBSL, INHS, JRYA, WSUC. Floral records: ASTERACEAE: Anaphalis margaritacea^3,59

23. Andrena (Cnemidandrena) nubecula Smith, 1853. County records: Pend Oreille^3,85, Walla Walla^2,3, Whitman^3,85, Yakima^3,85. Seasonality: Aug² (1988^2,3). Collections: INHS

24. Andrena (Cnemidandrena) scutellinitens Viereck, 1916. County records: Okanogan^1,2,3,59. Seasonality: Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL. Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Anaphalis margaritacea⁵⁹, Erigeron speciosus^3,59

25. Andrena (Cnemidandrena) sulcata Donovan, 1977. County records: Adams^1,3,85, Benton^2,3,7, Chelan^3,85, Yakima^2,3. Seasonality: Sep^1,2,3,7, Oct² (1991²). Collections: INHS, NMNH, WSUC. Holotype. USA, Washington, Adams County, Ritzville; 9 September 1920; RC Shannon; Type No. 71075, USNM ENT 00533741. Paratype. USA, Washington, Chelan County, Wenatchee; 25 September 1938; J Standish

26. Andrena (Cnemidandrena) surda Cockerell, 1910. County records: Kittitas^2,3,85, Pacific^3,85, Yakima^3,85. Seasonality: Sep^2,3 (1989^2,3). Collections: INHS

27. † Andrena (Cremnandrena) anisochlora Cockerell, 1936. County records: Clark^1,2. Seasonality: May^1,2 (2020^1,2). Collections: iNaturalist

28. Andrena (Dactylandrena) berberidis Cockerell, 1905. County records: King^3,16, Kittitas^2,3, Pierce¹⁶, Thurston¹³³, Whitman^3,16. Seasonality: Apr², May^2,3,133, June¹³³ (2020¹³³). Collections: INHS. Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Eriophyllum lanatum¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³

29. Andrena (Dactylandrena) porterae Cockerell, 1900. County records: King^1,2,117, Kittitas^2,3. Seasonality: Feb^2,3, Apr^1,2,117 (1994²). Collections: INHS, NMNH. [= Andrena neurona Viereck, 1904]. Holotype. USA, Washington, King County, Seattle; 17 April 1896

30. Andrena (Dasyandrena) cristata Viereck, 1916. County records: Pierce^3,17

31. Andrena (Dasyandrena) obscuripostica Viereck, 1916. County records: Pierce¹⁷

32. Andrena (Diandrena) chalybioides (Viereck, 1904). Collections: NMNH. [= Andrena (Parandrena) perchalybia Viereck, 1916]. Holotype. USA, Washington State; HK Morrison

33. Andrena (Diandrena) cuneilabris Viereck, 1926. County records: Thurston¹³³. Seasonality: May¹³³ (2020¹³³). Floral records: RANUNCULACEAE: Ranunculus occidentalis¹³³

34. Andrena (Diandrena) evoluta Linsley and MacSwain, 1961. County records: Adams^3,62, Okanogan^1,2,3,4,59, Whitman^3,7,62. Seasonality: Apr⁷, Jun^1,2,3,4, Jul^1,2,23 (2004^1,2,3,4,59). Collections: BBSL, WSUC. Floral records: ASTERACEAE: Arnica sororia⁵⁹, Crepis atrabarba^3,59; LILIACEAE: Calochortus lyallii⁵⁹

35. Andrena (Diandrena) nothocalaidis (Cockerell, 1905). County records: Adams^3,62, Benton^1,2,7, Chelan^3,62, Klickitat^1,2, Okanogan^3,7,62, Pierce⁶², Spokane^1,2, Whitman⁶², Yakima^3,62. Seasonality: Mar^1,2, May^1,2, Jun^1,2, Jul^1,2 (2015^1,2). Collections: BBSL, WSUC

36. † Andrena (Diandrena) subchalybea Viereck, 1916. County records: Kittitas². Seasonality: Apr², May² (1989²). Collections: INHS

37. Andrena (Geissandrena) trevoris Cockerell, 1897. County records: Asotin^2,3,20, Columbia^3,20, Island^3,20, Jefferson^3,20, King^1,3,20, Kitsap^3,20, Klickitat^3,20, Pierce^3,20, San Juan^2,3,20,136, Thurston^1,2,3,20,133, Walla Walla^1,2,3,20, Whatcom³, Whitman^2,3,20. Seasonality: Jun^1,2,20, Jul^1,2,133, Aug³ (2017^133,136). Collections: BBSL, INHS, JRYA, NMNH, WSUC. [= Andrena semipolita Viereck, 1904]. Holotype. USA, Washington, Thurston County, Olympia; 12 June 1895; Type No. 18952, USNM ENT 00533746. Floral records: CAPRIFOLIACEAE: Symphoricarpos albus^133,136

38. Andrena (Gonandrena) flocculosa LaBerge and Ribble, 1972. County records: Kittitas^2,3, Pierce^3,20, Thurston¹³³, Whitman^3,7,20, Yakima^1,2,3,7,20. Seasonality: May^1,2,3,20,133 (2017¹³³). Collections: INHS, NMNH, WSUC. Holotype. USA, Washington, Yakima County, North Yakima; 20 May 1903; E Jenne. Lectotype. USA, Washington, Pierce County, Parkland; 14 May 1962; R. Tentineh. Floral records: ASPARAGACEAE: Camassia quamash¹³³

39. Andrena (Holandrena) cressonii infasciata Lanham, 1949. County records: Benton^1,3,16, King^3,16, Kittitas^2,3, Pierce^3,16, Walla Walla^1,2,16, Whitman^1,2,3,7,8,16, Yakima^3,16. Seasonality: Apr^1,3,7, May^1,2,3,7, Jun^1,2,3,7 (2003²). Collections: BBSL, INHS, UCRC, WSUC

40. † Andrena (Larandrena) miserabilis Cresson, 1872. County records: Benton⁷, Kittitas^2,3, Okanogan⁷, Whitman⁷. Seasonality: May^2,3 (1989^2,3). Collections: INHS, WSUC. Floral records: ROSACEAE: Physocarpus malvaceus⁸

41. Andrena (Leucandrena) barbilabris (Kirby, 1802) County records: Benton^1,2,7, Chelan⁷, Clallam^1,2,3,15, Island^3,15, King^3,7,15,117, Pacific^3,15, Pierce^1,3, Snohomish^1,2,3,15, Thurston^3,15,117, Whitman^3,7,15, Yakima⁷. Seasonality: Mar^1,2, Apr^1,2,3,7,117, May^1,3,7, Jun^1,117, Jul^1,2, Aug¹, Sep¹ (2015^1,2). Collections: AMNH, BBSL, INHS, UCRC, WSUC. [= Andrena macgillivrayi Cockerell, 1897]. [= Andrena placida Smith, 1853]

42. ‡ Andrena (Melandrena) carlini Cockerell, 1901. County records: King^1,2,3,117. Seasonality: Apr¹¹⁷, May^1,2,3 (1919^1,2,3). Collections: OSUC. Floral records: GROSSULARIACEAE: Ribes¹¹⁷

43. Andrena (Melandrena) cerasifolii Cockerell, 1896. County records: Stevens^3,15, Whitman^3,15

44. ‡ Andrena (Melandrena) commoda Smith, 1879. County records: Columbia¹⁸, Klickitat^3,18, Pierce^3,18, Walla Walla^3,18, Whitman^1,2,3,7,18, Yakima^3,18. Seasonality: May^3,7, Jun^1,2,3 (1969^1,2,3). Collections: BBSL, UCRC, WSUC

45. † Andrena (Melandrena) cyanura Cockerell, 1916. County records: Benton⁷, Kittitas⁷. Collections: WSUC

46. † Andrena (Melandrena) erythrogaster (Ashmead, 1890). County records: Kittitas^2,3. Seasonality: May^2,3 (1989^2,3). Collections: INHS

47. Andrena (Melandrena) hallii Dunning, 1898. County records: Whitman^1,2,3,21,117. Collections: NMNH. Lectotype. USA, Washington, Whitman County, Pullman; CV Piper; USNM ENT 00533619

48. Andrena (Melandrena) lupinorum Cockerell, 1906. County records: King^3,18, Thurston¹³³, Whitman^3,18. Seasonality: April¹³³, May¹³³, June¹³³ (2020¹³³). Floral records: ASPARAGACEAE: Camassia quamash¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus¹³³; ERICACEAE: Arctostaphylos uva-ursi¹³³; LILIACEAE: Fritillaria affinis¹³³; ROSACEAE: Potentilla gracilis¹³³

49. Andrena (Melandrena) nivalis Smith, 1853. County records: Asotin^3,18, Benton^3,7,18, Garfield^3,18, Jefferson^1,2, King^3,18, Klickitat^1,2, Okanogan^1,2,3,59, Pierce^3,18, San Juan^1,2,3,22,124, Spokane^1,2, Thurston^{1,2,3,18,117,133}, Walla Walla^3,18, Whitman^{1,2,3,7,18,117}. Seasonality: Apr^1,2,133, May^{1,2,7,18,117,133}, Jun^1,2,3,133, Jul^1,2 (2020¹³³). Collections: BBSL, NMNH, PWRC, WSUC. [= Andrena compactiscopa Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman; CV Piper. [= Andrena junonia Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman; May 1895; CV Piper. [= Andrena pluvialis Cockerell, 1901]. Holotype. USA, Washington, Thurston County, Olympia; 1 May 1894; T Kincaid; Type No. 18939, USNM ENT 00533694. [= Andrena solidula Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman; CV Piper. Floral records: APIACEAE: Lomatium utriculatum¹³³; ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Taraxacum officinale¹³³; ERICACEAE: Arcostaphylos uva-ursi¹³³; ONAGRACEAE: Chamerion angustifolium¹³³; ROSACEAE: Physocarpus malvaceus⁸, Potentilla gracilis¹³³, Rosa nutkana ssp. nutkana^3,59

50. Andrena (Melandrena) perplexa Smith, 1853. County records: Cowlitz^1,2,3, Garfield¹³⁵, Kittitas^2,3, Thurston¹³³, Whitman^2,3,7,21,117. Seasonality: Apr¹¹⁷, May^{1,2,3,7,117,133,135}, Jun^7,133 (2023¹³⁵). Collections: BBSL, INHS, NMDG. [= Andrena viburnella Graenicher, 1903]. Floral records: BRASSICACEAE: Teesdalia nudicaulis¹³³; ROSACEAE: Potentilla gracilis¹³³

51. Andrena (Melandrena) pertristis carliniformis Viereck and Cockerell, 1914. County records: Chelan^3,18, San Juan⁵, Yakima^3,18. Seasonality: Apr⁵, May⁵ (2009⁵). Floral records: APIACEAE: Heracleum sphondylium ssp. montanum⁵; ASPARAGACEAE: Camassia quamash⁵; GERANIACEAE: Geranium molle⁵; RANUNCULACEAE: Ranunculus californicus × occidentalis⁵

52. † Andrena (Melandrena) sola Viereck, 1916. County records: Klickitat^1,2, San Juan^1,2,3,6,124, Spokane^1,2. Seasonality: Apr^1,2, May^1,2, Jun⁶ (2017⁶). Collections: BBSL, PWRC, WSDA

53. Andrena (Melandrena) subaustralis Cockerell, 1898. County records: Benton^2,3,7, Kittitas^2,3, Thurston¹³³, Whitman^1,3,7,21,117, Yakima^3,21. Seasonality: Apr^1,2,3,7,133, May⁷ (2017¹³³). Collections: INHS, WSUC. Floral records: ASTERACEAE: Balsamorhiza sagittata⁸, Taraxacum officinale¹³³

54. Andrena (Melandrena) subtilis Smith, 1879. County records: Island^3,21, Kittitas^2,3,21, San Juan^5,136, Spokane^1,2,3,21, Walla Walla^3,21, Whitman^{1,2,3,7,8,21,117}, Yakima^3,21. Seasonality: Apr^1,2,5,7, May^2,3,5,7, Jun^1,7 (2017¹³⁶). Collections: BBSL, INHS, WSUC. Floral records: BRASSICACEAE: Teesdalia nudicaulis⁵; GERANIACEAE: Geranium molle⁵; RANUNCULACEAE: Ranunculus californicus × occidentalis⁵; ROSACEAE: Rosa⁸, Rosa nutkana¹³⁶

55. Andrena (Melandrena) transnigra Viereck, 1904. County records: Jefferson^1,2, King^1,2,18,117, Kitsap^2,3,18, Kittitas^2,3,7, Klickitat^1,2, Pierce^1,2,3,18, Skagit², Spokane^3,18, Stevens^1,2, Thurston^7,133. Seasonality: Mar⁷, Apr^{1,2,3,7,18,117,133}, May^1,2,3,7, Jun^1,2,7 (2017¹³³). Collections: BBSL, BugGuide, INHS, NMNH, PCYU, WSUC. Holotype. USA, Washington, King County, Seattle; 17 April 1896; T Kincaid. Floral records: ERICACEAE: Arctostaphylos uva-ursi¹³³. Comments: Sheffield (2020) resurrected Andrena cyanura from synonymy with Andrena transnigra. We did not inspect all of the recorded specimens, and it is possible that some of these records represent A. cyanura.

56. Andrena (Melandrena) vicina Smith, 1853. County records: King^3,18,117, Kittitas^2,3, San Juan^{1,2,3,124,136}, Snohomish^1,2,3,23, Stevens^1,3,18, Thurston^3,18,117,133, Whitman⁸. Seasonality: Jan^1,3, Mar^2,133, Apr¹¹⁷, May^1,2,3, Jun^1,117, Jul^1,2, Aug^1,2, Nov^2,3, Dec² (2017^133,136). Collections: INHS, PWRC, WSUC. Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Taraxacum officinale¹³⁶; BERBERIDACEAE: Berberis aquifolium¹³⁶; GERANIACEAE: Geranium viscosissimum⁸; ROSACEAE: Holodiscus discolor⁸, Physocarpus malvaceus⁸, Rosa⁸, Rubus parviflorus⁸

57. ‡ Andrena (Micrandrena) candidiformis Viereck and Cockerell, 1914. County records: Spokane^3,7,63. Seasonality: Jun⁷ (1912⁷). Collections: WSUC

58. Andrena (Micrandrena) chlorogaster Viereck, 1904. County records: Chelan⁷, Kittitas^2,3, Klickitat^1,2, Thurston¹³³, Walla Walla^3,63, Whitman^3,7,63, Yakima^2,3,7. Seasonality: Apr^1,2,3,7,133, May^1,3,7,133, Jun¹³³ (2020¹³³). Collections: AMNH, INHS, WSUC. Floral records: APIACEAE: Lomatium pugetensis¹³³, L. utriculatum¹³³; ASTERACEAE: Leucanthemum vulgare¹³³; OROBANCHACEAE: Castilleja levisecta¹³³; RANUNCULACEAE: Ranunculus occidentalis¹³³; ROSACEAE: Fragaria virginiana¹³³, Physocarpus malvaceus⁸, Potentilla⁸, P. gracilis¹³³; SALICACEAE: Salix⁷

59. Andrena (Micrandrena) illinoiensis Robertson, 1891. County records: Grant^3,7,63, Thurston¹³³, Whitman^3,7,63,117, Yakima^2,3. Seasonality: Apr^2,3,7,117, May^3,7,133, Jul⁷ (2017¹³³). Collections: INHS, UCRC, WSUC. Floral records: ROSACEAE: Fragaria virgniana¹³³

60. Andrena (Micrandrena) melanochroa Cockerell, 1898. County records: Chelan^3,63, Pierce⁷, Spokane^1,2, Thurston^1,2,3,63,117, Whitman^3,7,8,63. Seasonality: May^1,2,7,117, Jun^1,2 (2011^1,2). Collections: BBSL, NMNH, WSUC. Holotype. USA, Washington, Thurston County, Olympia; 25 May 1894; T Kincaid; Type No. 18917, USNM ENT 00533649. Floral records: APIACEAE: Lomatium⁸; GROSSULARIACEAE: Ribes aureum⁸; ROSACEAE: Malus domestica⁸

61. Andrena (Micrandrena) microchlora Cockerell, 1922. County records: Benton^1,2,3,7, Kittitas⁷, Klickitat^1,2,3,63, Lincoln⁷, Spokane^1,2, Thurston¹³³, Whitman^{1,3,6,7,61,63}, Yakima^2,3. Seasonality: Mar^1,2,7,61, Apr^{1,2,3,7,61,133}, May^1,2,6,7, Jun⁷ (2018¹³³). Collections: BBSL, INHS, WSDA, WSUC. Floral records: APIACEAE: Lomatium utriculatum¹³³

62. ‡ Andrena (Micrandrena) nigrae Robertson, 1905. County records: Asotin⁶³, Whitman^3,7,63. Seasonality: May⁷ (1920⁷). Collections: WSUC

63. Andrena (Micrandrena) piperi Viereck, 1904. County records: Asotin^3,63,135, Benton^1,2,3,7,63, Chelan^3,7,63, Kittitas^2,3, Spokane^1,2, Walla Walla⁷, Whitman^{1,2,3,7,63,117}, Yakima^2,3. Seasonality: Mar¹³⁵, Apr^1,2,3,63, May^1,2,3,63 (2021¹³⁵). Collections: BBSL, INHS, NMDG, WSUC. Holotype. USA, Washington, Whitman County, Pullman; CV Piper

64. ‡ Andrena (Micrandrena) salictaria Robertson, 1905. County records: Spokane^3,7,63, Whitman^3,7,63. Seasonality: Apr⁷, May⁷, Jun⁷, Jul⁷ (1930⁷). Collections: WSUC

65. Andrena (Onagrandrena) raveni Linsley and MacSwain, 1961. County records: Adams⁸⁶, Benton⁷. Seasonality: Apr⁷ (1995⁷). Collections: WSUC

66. Andrena (Parandrena) andrenoides (Cresson, 1878). County records: Garfield¹³⁵, Thurston¹¹⁷, Yakima^2,3. Seasonality: Apr^2,3, May^117,135 (2023¹³⁵). Collections: INHS, NMDG. [= Parandrena andrenoides (Cresson, 1878)]

67. ‡ Andrena (Parandrena) nevadensis (Cresson, 1879). County records: Thurston^3,20, Whitman^3,7,20, Yakima^3,20. Seasonality: Apr⁷ (1936⁷). Collections: WSUC

68. Andrena (Plastandrena) crataegi Robertson, 1893. County records: Asotin⁷, King^3,19, Kittitas^2,3, Okanogan⁷, Pierce^1,3,19, Spokane⁷, Stevens^3,7,19, Thurston¹³³, Walla Walla^1,2, Whitman^1,2,3,7, Yakima^3,7. Seasonality: Jan¹, Apr^2,3, May^2,7,133, Jun^1,2,3,7, Jul^1,2 (2017¹³³). Collections: BBSL, INHS, UCRC, WSUC. Floral records: APIACEAE: Lomatium pugetensis¹³³; ROSACEAE: Physocarpus malvaceus⁸

69. Andrena (Plastandrena) prunorum prunorum Cockerell, 1896. County records: Adams⁷, Asotin⁷, Benton^1,2,3,7, Chelan^1,2,3,7, Clallam^1,2, Ferry², Franklin^{1,2,3,7,19,117}, Grant^1,2,3,7, Island^3,7,19, Jefferson^1,2, King^1,2,3,7,117, Kitsap^2,23,134, Kittitas^1,2,3,7, Klickitat^1,2,3, Lincoln⁷, Mason⁷, Okanogan^1,2,3,7,59, Pierce⁷, San Juan^{1,2,3,5,6,19,22,124}, Skagit^1,2, Snohomish^1,2,3,23, Spokane^1,2,3,7, Stevens^1,7, Thurston^{1,2,3,6,19,117,133}, Walla Walla^1,2,3,7,71, Whitman^{1,2,3,6,7,8,117}, Yakima^1,2,3,7,23. Seasonality: Mar^1,23,7, Apr^1,2,3,7,23, May^{1,2,3,5,7,19,23,117,133}, Jun^{1,2,3,5,6,7,19,117,133}, Jul^{1,2,3,6,7,23,133}, Aug^1,2,3,6,7, Sep², Oct⁷ (2022^1,2). Collections: AMNH, BBSL, BugGuide, iNaturalist, INHS, NMNH, PCYU, PWRC, SEMC, WSDA, WSUC. [= Andrena kincaidii Cockerell, 1897]. Holotype. USA, Washington, Thurston County, Olympia; 2 June 1894; Type No. 3698, USNM ENT 00533636. [= Andrena pascoensis Cockerell, 1897]. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; Type No. 18936, USNM ENT 00533683. Floral records: APIACEAE: Chaerophyllum temulum³, Lomatium⁸; ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Anaphalis margaritacea^3,59; BRASSICACEAE: Sisymbrium altissimum⁸, Teesdalia nudicaulis¹³³; CACTACEAE: Pediocactus nigrispinus⁷; CARYOPHYLLACEAE: Cersatium arvense¹³³; GERANIACEAE: Geranium viscosissimum⁸; HYDRANGEACEAE: Philadelphus lewisii^8,23; ONAGRACEAE: Clarkia amoena¹³³; ROSACEAE: Fragaria virginiana¹³³, Holodiscus discolor⁸, Physocarpus malvaceus⁸, Potentilla gracilis¹³³; SALICACEAE: Salix⁷

70. Andrena (Ptilandrena) astragali Viereck and Cockerell, 1914. County records: Jefferson^1,2, Kittitas^3,14, Okanogan^1,2,3,59, San Juan⁵, Spokane^1,2, Thurston¹³³, Whitman⁷. Seasonality: Apr^1,2, May^1,2,5,133, Jun^{1,2,3,5,7,133} (2023⁷). Collections: BBSL, WSUC. Floral records: APIACEAE: Lomatium pugetensis¹³³; ASPARAGACEAE: Triteleia hyacinthina¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Eriophyllum lanatum¹³³, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³, Solidago simplex¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus¹³³; CARYOPHYLLACEAE: Cerastrium arvense¹³³; FABACEAE: Lupinus albicaulis¹³³; MELANTHIACEAE: Toxicoscordion venenosus¹³³, T. venenosum var. venenosum⁵; RANUNCULACEAE: Ranunculus occidentalis¹³³; ROSACEAE: Potentilla gracilis¹³³

71. Andrena (Ptilandrena) auricoma Smith, 1879. County records: Garfield¹³⁵, Kittitas^2,3, Walla Walla^3,14, Whitman⁷. Seasonality: Apr², May¹³⁵, Jun⁷, Jul⁷ (2023¹³⁵). Collections: INHS, NMDG, WSUC. Floral records: ASTERACEAE: Achillea millefolium⁸; ROSACEAE: Physocarpus malvaceus⁸, Potentilla⁸

72. Andrena (Ptilandrena) caerulea Smith, 1879. County records: Island^3,7, Kittitas^1,2,3,7, Klickitat^1,2, Lewis⁷, Pierce¹⁴, Thurston^{1,2,3,14,117,133}, Whitman^7,8. Seasonality: Apr^3,7,133, May^{1,2,7,14,117,133}, Jun^1,2,133, Jul^1,2 (2020¹³³). Collections: BBSL, NMNH, SEMC, UCRC, WSUC. [= Andrena coerulea var. territa Cockerell, 1898]. Holotype. USA, Washington, Thurston County, Olympia; 20 May 1894; Type No. 18943, USNM ENT 00533743. [= Pterandrena acrypta Viereck, 1904]. [= Pterandrena erigenoides Viereck, 1904]. Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Microseris laciniata¹³³; CARYOPHYLLACEAE: Cerastium arvense¹³³; CAPRIFOLIACEAE: Symphoricarpos albus¹³³; RANUNCULACEAE: Ranunculus⁸, R. occidentalis¹³³; ROSACEAE: Prunus virginiana⁸

73. Andrena (Ptilandrena) chlorura Cockerell, 1916. County records: King^3,14, Thurston¹³³, Whitman^3,14. Seasonality: May¹³³ (2017¹³³). Floral records: ROSACEAE: Fragaria virginiana¹³³

74. Andrena (Ptilandrena) lawrencei Viereck and Cockerell, 1914. County records: Benton^1,2,7, Kittitas^2,3,7,14, Okanogan¹⁴, Spokane^1,2, Whitman^3,14, Yakima^3,14. Seasonality: Mar^1,2, Apr^1,2,3,7, May^1,2,7 (2015^1,2). Collections: BBSL, INHS, WSUC

75. Andrena (Ptilandrena) nigrihirta (Ashmead, 1890). County records: Clallam^3,14, Grays Harbor^3,14, King^3,14, Pierce^1,3,14, Spokane^1,2, Thurston¹³³, Whitman^{3,7,14,114,117}. Seasonality: Apr^1,2, May^1,2,7,14,117, Jun¹³³, Jul^1,3 (2018¹³³). Collections: BBSL, INHS, WSUC. [= Andrena decussata Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman. Floral records: CAPRIFOLIACEAE: Symphoricarpos albus¹³³

76. Andrena (Ptilandrena) nigrocaerulea Cockerell, 1897. County records: Chelan^7,130, Clallam^3,14, Columbia¹⁴, Island⁷, King^1,2,3,14,117, Kittitas^3,14, Klickitat^1,2, Pierce^3,14, San Juan^1,2,124, Spokane^1,2, Thurston^3,14,117,133, Walla Walla^1,2,3,14, Whitman^{1,2,3,6,7,8,14,61,117}, Yakima^3,14. Seasonality: Apr^1,2,7,61,133, May^{1,2,7,14,117,133}, Jun^{1,2,3,6,7,117,133}, Jul^1,2,7 (2020¹³³). Collections: BBSL, NMNH, PWRC, WSDA, WSUC. [= Andrena seattlensis Viereck, 1904]. Holotype. USA, Washington, King County, Seattle; 17 May 1896. [= Pterandrena nigrocaerulea Viereck, 1904]. Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Crepis capillaris¹³³, Eriophyllum lanatum¹³³, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Taraxacum officinale¹³³; BORAGINACEAE: Hackelia venusta¹³⁰; BRASSICACEAE: Teesdalia nudicaulis¹³³; CAMPANULACEAE: Campanula rotundifolia¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; CARYOPHYLLACEAE: Cerastium arvense¹³³; ERICACEAE: Arctostaphylos uva-ursi¹³³; FABACEAE: Vicia sativa¹³³; GERANIACEAE: Geranium viscosissimum⁸; IRIDACEAE: Sisyrinchium idahoense¹³³; PLANTAGINACEAE: Collinsia grandiflora¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; RANUNCULACEAE: Ranunculus occidentalis¹³³; ROSACEAE: Potentilla gracilis¹³³

77. Andrena (Ptilandrena) pallidiscopa (Viereck, 1904). County records: Benton⁷, Kittitas⁷, Klickitat^3,15, Walla Walla^3,15, Whitman^3,7,15. Seasonality: Apr⁷, May⁷ (2023⁷). Collections: WSUC

78. Andrena (Ptilandrena) ribblei LaBerge, 1977. County records: Okanogan^1,2,3,59, Pierce^3,17. Seasonality: Jul^1,2,3,17, Aug¹⁷ (2004^1,2,3,59). Collections: BBSL. Floral records: BRASSICACEAE: Smelowskia calycina⁵⁹; POLEMONIACEAE: Polemonium pulcherrimum^3,59; ROSACEAE: Potentilla gracilis⁵⁹

79. Andrena (Scaphandrena) chapmanae Viereck, 1904. County records: Adams⁷, Chelan^1,2,3, Garfield^1,2,3,10,46, Klickitat^1,2,7, Whitman⁷. Seasonality: Mar⁷, Apr^1,2, May^1,2,3, Jun⁷ (2012^1,2). Collections: BBSL, WSUC

80. Andrena (Scaphandrena) gordoni Ribble, 1974. County records: Benton^1,2, Whitman⁶⁰. Seasonality: Mar^1,2, Apr^1,2, May⁶⁰ (2015^1,2). Collections: AMNH, BBSL. Paratype. USA, Washington, Whitman County, Pullman; May; AL Melander; WSU No. 402.

81. Andrena (Scaphandrena) merriami Cockerell, 1901. County records: Asotin^3,60, Benton^1,2,3,7, Kittitas^2,3,60, Klickitat^1,2, Okanogan⁷, Spokane^1,2, Walla Walla^3,60, Whitman^{1,2,3,6,7,8,60,117}, Yakima^3,60. Seasonality: Mar^1,7, Apr^1,2,3,7,117, May^1,2,3,7,117, Jul⁶ (2015^1,2). Collections: BBSL, INHS, WSDA, WSUC. [= Andrena pullmani Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman. Floral records: APIACEAE: Lomatium⁸; ROSACEAE: Prunus avium⁸

82. Andrena (Scaphandrena) scurra Viereck, 1904. County records: Adams^3,7,60, Benton^1,2,3,7,60, Chelan^1,2,3,7,60, Garfield^1,2,3,4,46, Grant^3,7,60, Kittitas^3,60, Okanogan^3,7,60, Spokane^1,2,3,60, Walla Walla^1,2,3, Whitman^1,2,3,4,7,60. Seasonality: Mar^1,2, Apr^1,2,3,7, May^1,2,3,4,7, Jun^1,2,3,7, Jul^1,2 (2015^1,2). Collections: BBSL, FMNH, INHS, PCYU, SEMC, WSUC

83. Andrena (Scaphandrena) shoshoni Ribble, 1974. County records: Whitman³². Seasonality: May³² (2013³²)

84. Andrena (Scaphandrena) sladeni Viereck, 1924. County records: Asotin^3,60, Benton⁷, Kittitas^3,60, Whitman^7,61, Yakima⁷. Seasonality: Mar^7,61, Apr^7,61 (1991⁶¹). Collections: WSUC

85. ‡ Andrena (Scaphandrena) walleyi Cockerell, 1932. County records: Spokane^3,60, Whitman⁷. Seasonality: May⁷ (1918⁷). Collections: WSUC

86. Andrena (Simandrena) angustitarsata Viereck, 1904. County records: Asotin^2,3,7,13, Ferry^1,2,3, King^1,2,3,7,13, Kittitas², Klickitat^1,2,3,13, Lewis^3,7,13, Pierce^3,7,13, Spokane^1,2,3,13, Thurston¹³³, Walla Walla^1,2,3,13, Whitman^{1,2,3,6,7,8,13,61,117}. Seasonality: Mar^3,7,61, Apr^1,2,7,133, May^1,2,3,7,133, Jun^1,2,6,7,133 (2020¹³³). Collections: AMNH, BBSL, INHS, NMNH, SEMC, UCDC, UCRC, WSDA, WSUC. [Andrena (Simandrena) angustitarsata Viereck, 1904]. Holotype. USA, Washington Territory. [= Andrena mustelicolor Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman; CV Piper. Floral records: APIACEAE: Lomatium⁸, L. pugetensis¹³³, L. utriculatum¹³³; ASTERACEAE: Achillea millefolium¹³³, Balsamorhiza deltoidea¹³³, Eriophyllum lanatum¹³³; BRASSICACEAE: Lepidium campestre¹³³, Teesdalia nudicaulis¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; RANUNCULACEAE: Ranunculus⁸; ROSACEAE: Malus domestica⁸, Physocarpus malvaceus⁸, Potentilla gracilis¹³³, Prunus virginiana⁸, Sorbus scopulina⁸, Rosa⁸, Rubus parviflorus⁸

87. Andrena (Simandrena) orthocarpi Cockerell, 1936. County records: Klickitat^1,2,3,13, Thurston¹³³. Seasonality: Apr^1,2, May¹³³ (2020¹³³). Collections: AMNH. Floral records: APIACEAE: Lomatium pugetensis¹³³, L. utriculatum¹³³

88. Andrena (Simandrena) pallidifovea (Viereck, 1904). County records: Benton^1,3,7,13, Chelan^1,2,3, Kittitas^2,3, Spokane^1,2,3,13, Thurston¹³³, Walla Walla^1,2,3,13, Whitman^3,7,8,13,117, Yakima^3,7,13. Seasonality: May^1,2,3,7, Jun^1,2,7,133, Jul¹ (2019¹³³). Collections: BBSL, INHS, WSUC. [= Pterandrena pallidifovea Viereck, 1904]. Floral records: ASTERACEAE: Eriophyllum lanatum^8,133, Solidago simplex¹³³

89. †* Andrena (Taeniandrena) wilkella (Kirby, 1802). County records: Whitman⁷. Seasonality: May⁷, Jun⁷ (2023⁷). Collections: WFBM, WSUC

90. Andrena (Thysandrena) candida Smith, 1879. County records: Adams^3,17, Asotin^3,17, Benton^2,3,7, Clark^3,17, Island^2,3,7,17, King^1,2,3,17,117, Kitsap^2,3, Pacific^3,17, Pierce^1,2,3,7,17, San Juan^3,17, Skagit^1,2,3,17, Spokane^1,2, Thurston^117,133, Walla Walla^1,2,3,17, Whatcom^1,3,17, Whitman^3,7,8,17,117, Yakima^3,7,17. Seasonality: Feb², Mar^2,3,7,117, Apr^1,2,3,7,117, May^1,2,7,133, Jun^1,2,117,133, Jul^1,2,3,7 (2020¹³³). Collections: AMNH, BBSL, INHS, NMNH, UCDC, UCRC, WSUC. [= Andrena subcandida Viereck, 1904]. Holotype. USA, Washington, King County, Seattle; 14 March 1896; T Kincaid. Floral records: APIACEAE: Lomatium⁸, L. utriculatum¹³³; ASTERACEAE: Balsamorhiza sagittata⁸; LAMIACEAE: Prunella vulgaris¹³³; ROSACEAE: Prunus avium⁸

91. Andrena (Thysandrena) knuthiana Cockerell, 1901. County records: Clallam³, King^3,17, Okanogan^1,2,3,59, Pierce^3,17, San Juan^3,5,17, Snohomish⁷, Walla Walla^3,17, Whitman^3,7,17. Seasonality: Apr^5,7, Jul^1,2,3,7 (2014³). Collections: BBSL, JRYA, WSUC

92. Andrena (Thysandrena) medionitens Cockerell, 1902. County records: Franklin^1,2,3,17,117, Grant⁷, Kittitas^1,2,3,17, Pierce^3,17, Spokane⁷, Walla Walla^1,2,3,17, Whitman^1,2,3,17. Seasonality: May^1,2,7,17,117, Jun¹, Jul^1,2 (2003²). Collections: BBSL, INHS, NMNH, SEMC, WSUC. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; Type No. 18921, USNM ENT 00533648

93. ‡ Andrena (Thysandrena) trizonata (Ashmead, 1890). County records: Pierce^1,3, Whitman^3,17. Seasonality: Mar¹, Apr^1,3 (1946^1,3). Collections: INHS. Floral records: ROSACEAE: Physocarpus malvaceus⁸

94. Andrena (Thysandrena) vierecki Cockerell, 1904. County records: King^3,17, Kittitas^2,3, Klickitat¹⁷, Thurston¹³³, Whitman^3,7,17, Yakima^3,17. Seasonality: Apr^2,3, May⁷, Jun¹³³ (2018¹³³). Collections: INHS, WSUC. Floral records: CAPRIFOLIACEAE: Symphoricarpos albus¹³³

95. Andrena (Thysandrena) w-scripta Viereck, 1904. County records: Asotin^3,17, Benton⁷, Chelan^3,17, Clallam³, Ferry^1,2,3,17, King^2,3,17, Kitsap^2,3, Kittitas^2,3, Klickitat^1,2, Pierce^3,17, Snohomish^1,3, Spokane^1,2, Thurston¹³³, Walla Walla^3,17, Whitman^2,3,7,17, Yakima^2,3. Seasonality: Mar⁷, Apr^2,3,7, May^1,2,3,7,133, Jul^1,2,3, Aug^1,2, Nov^1,3 (2020¹³³). Collections: BBSL, INHS, JRYA, SEMC, WSUC. Floral records: APIACEAE: Lomatium pugetensis¹³³

96. Andrena (Trachandrena) amphibola (Viereck, 1904). County records: Asotin^3,12, Benton^1,2, Chelan^3,12, Island^3,7,12, Jefferson^3,12, King^2,3,12, Kitsap^3,12, Kittitas³, Klickitat^1,2, Mason^3,12, Pacific^1,2,7, San Juan^1,2,3,12, Thurston^3,7,12,133, Whitman^3,7,8,12. Seasonality: Apr^1,2,3,7, May^1,7,133, Jun⁷, Jul^1,7 (2019¹³³). Collections: BBSL, EMEC, INHS, NMNH, UCRC, WSUC. [= Trachandrena crassihirta Viereck, 1904]. Holotype. USA, Washington State (presumably)^12,116. [= Trachandrena hadra Viereck, 1904]. Holotype. USA, Washington Territory. Floral records: ASPARAGACEAE: Camassia quamash¹³³; LAMIACEAE: Agastache urticifolia⁸

97. ‡ Andrena (Trachandrena) cleodora cleodora (Viereck, 1904). County records: King^2,3,12, Kitsap^3,12, Klickitat^3,12, Pierce^3,12, Stevens^3,12, Whitman^3,12, Yakima^3,12. Seasonality: Jul³ (1927³). Collections: INHS, UCRC

98. Andrena (Trachandrena) cupreotincta Cockerell, 1901. County records: Benton^1,2,3,7, Ferry^3,12, Island^3,12, King^1,2,3,12, Kittitas^2,3, Lincoln^3,7,12, Mason^1,2,3,12,116, Pacific^3,12, Pierce^3,12, San Juan^3,12, Snohomish^3,12, Spokane^3,12, Stevens^3,12, Thurston^3,12,133, Walla Walla^3,12, Whitman^3,7,12. Seasonality: Apr^1,2,3,7,12, May^{1,2,3,7,12,133}, Jun^2,7 (2017¹³³). Collections: AMNH, BBSL, INHS, NMNH, UCDC, WSUC. Holotype. USA, Washington, Mason County, Skokomish River; 26 April 1892; T Kincaid; Type No. 18937, USNM ENT 00532972. [= Trachandrena ochreopleura Viereck, 1904]. Holotype. USA, Washington, Mason County, Skokomish River; 5 May 1912; USNM Type No 28535. Floral records: PLUMBAGINACEAE: Armeria maritima¹³³

99. ‡ Andrena (Trachandrena) cyanophila Cockerell, 1906. County records: Spokane^1,2,3,12, Whitman^3,7,12. Seasonality: May⁷, Jun⁷, Jul^1,2 (1945^1,2). Collections: INHS, WSUC

100. ‡ Andrena (Trachandrena) forbesii Robertson, 1891. County records: Spokane³, Whitman^1,3,7,12. Seasonality: Apr⁷, May^1,3,7, Jun^1,7 (1924³). Collections: BBSL, INHS, UCRC, WSUC

101. Andrena (Trachandrena) fuscicauda (Viereck, 1904). County records: King^1,2,3,12, Kitsap^3,12, Pacific⁷, Pierce^1,2,3, Thurston¹³³. Seasonality: Apr^1,2,3,7, May^1,2,133 (2018¹³³). Collections: INHS, NMNH, UCDC, WSUC. [= Trachandrena fuscicauda Viereck, 1904]. Holotype. USA, Washington Territory; PANS 10293. Floral records: ASPARAGACEAE: Camassia quamash¹³³

102. †‡ Andrena (Trachandrena) hippotes Robertson, 1895. County records: Benton⁷, Pierce³, Whitman^1,3,7, Yakima^1,3. Seasonality: Apr^1,3,7, May^1,7, Jun^3,7 (1966³). Collections: CUIC, INHS, WSUC

103. Andrena (Trachandrena) mariae Robertson, 1891. County records: Lincoln⁷, Thurston¹³³, Whitman^3,7,12. Seasonality: Apr¹³³, May¹³³, Jun⁷ (2017¹³³). Collections: WSUC. Floral records: APIACEAE: Lomatium utriculatum¹³³; CARYOPHYLLACEAE: Cersatium arvense¹³³

104. Andrena (Trachandrena) miranda Smith, 1879. County records: Asotin^3,12, Columbia¹², King^3,12, Kitsap^3,12, Klickitat^1,2, Okanogan^1,2,3,59, Pend Oreille^3,12, Pierce^3,12, Spokane^1,2, Stevens^3,12, Thurston^1,2,3,12,133, Walla Walla^3,12, Whatcom⁶, Whitman^2,3,7,12. Seasonality: May^7,133, Jun^{1,2,3,6,7,12,133}, Jul^1,2,3,7, Aug^1,2 (2020¹³³). Collections: BBSL, CUIC, INHS, NMNH, WSDA, WSUC. [= Andrena grandior Cockerell, 1897]. Holotype. USA, Washington, Thurston County, Olympia; 18 June 1895; Type No. 18954, USNM ENT 00533617. Floral records: APIACEAE: Lomatium utriculatum¹³³; ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Achillea millefolium¹³³; BRASSICACEAE: Lepidium campestre¹³³; CAPRIFOLIACEAE: Symphoricarpos albus¹³³; ROSACEAE: Potentilla gracilis^3,59, Rubus parviflorus^3,59

105. Andrena (Trachandrena) quintiliformis Viereck, 1916. County records: Okanogan^1,2,3,59, Whitman^3,7,12, Yakima^3,12. Seasonality: May⁷, Jun^1,2,3,7, Jul^1,2,3,7, Aug^1,2,3 (2004^1,2,3). Collections: BBSL, WSUC. Floral records: ROSACEAE: Potentilla gracilis^3,59

106. Andrena (Trachandrena) salicifloris Cockerell, 1897. County records: Clallam^3,12, Grays Harbor^3,12, Island^3,12, Jefferson^1,2,3, King^2,3,7,12,116, Kitsap^2,3,12, Klickitat^1,2,3, Okanogan^1,2,3,59, Pacific^3,12, Pierce^1,2,3,12, Skagit¹⁰, Snohomish^1,2,3,12, Spokane^1,2, Stevens^1,2, Thurston^{1,2,3,12,116,133}, Whitman^1,3,7,12. Seasonality: Apr^{1,2,3,7,12,116}, May^{1,2,3,7,12,116,133}, Jun^1,2,3,7, Jul^1,3, Aug², Sep¹, Nov^1,3 (2017¹³³). Collections: AMNH, BBSL, INHS, NMNH, OSUC, UCMC, WSUC, WWUC. [= Trachandrena auricauda Viereck, 1904]. Holotype. USA, Washington State. Floral records: ASPARAGACEAE: Camassia quamash¹³³; GROSSULARIACEAE: Ribes¹¹⁶; ROSACEAE: Rosa nutkana ssp. nutkana^3,59; SALICACEAE: Salix¹¹⁶

107. Andrena (Trachandrena) semipunctata Cockerell, 1902. County records: King^1,2,3,12, Kittitas^2,3, Lincoln^3,12, Yakima^2,3,12. Seasonality: Apr^1,2,3,12, Jun^1,2 (1989^2,3). Collections: INHS, NMNH. Holotype. USA, Washington, King County, Seattle; 5 April 1896; T Kincaid; Type No. 18922, USNM ENT 00533728

108. Andrena (Trachandrena) sigmundi Cockerell, 1902. County records: Kitsap^2,3, Thurston¹³³, Whitman^3,12. Seasonality: Apr^2,3, May¹³³ (2019¹³³). Collections: INHS. Floral records: ASPARAGACEAE: Camassia quamash¹³³

109. Andrena (Trachandrena) striatifrons Cockerell, 1897. County records: Benton⁷, King^3,12, Kittitas^2,3, Pacific^3,12, Pierce^3,12, Thurston^1,2,3,12, Whitman^1,2,3,7,12, Yakima^2,3,7,12. Seasonality: Apr^1,2,3,7,12, May⁷, Jun^3,7 (1989^2,3). Collections: INHS, NMNH, WSUC. Holotype. USA, Washington, Thurston County, Olympia; 19 April 1894; T Kincaid; Type No. 18945, USNM ENT 533735. [= Trachandrena pernuda Viereck, 1904]. Holotype. USA, Washington, Whitman County, Pullman; CV Piper.

Panurginae: Calliopsini

Genus Calliopsis Smith

110. Calliopsis (Nomadopsis) edwardsii Cresson, 1878. County records: Klickitat^1,2, Spokane³. Seasonality: Jul^1,2,3, Aug^1,2, Sep^1,2 (2011^1,2). Collections: BBSL, UCRC

111. Calliopsis (Nomadopsis) personata Cockerell, 1897. County records: Adams³, Benton^1,2,3, Franklin^1,2,118,123, Walla Walla^1,2,3. Seasonality: May^{1,2,3,118,123}, Jun^1,2,3, Jul^1,2,3 (1995^1,2,3). Collections: AMNH, BBSL, NMNH, UCRC. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; Type No. 18985, USNM ENT 00533826.

112. †‡ Calliopsis (Nomadopsis) scutellaris Fowler, 1899. County records: Adams³. Seasonality: Jul³ (1920³). Collections: UCRC

113. ‡ Calliopsis (Nomadopsis) xenus (Rozen, 1958). County records: Pierce¹²³ (Yakima^1,2,3). Seasonality: Jul^1,2,3,123 (1949^1,2,3,123). Collections: SEMC. Paratype. USA, Washington, Chinook Pass; 29 July 1949; RH Beamer. Floral records: BORAGINACEAE: Mertensia paniculata^1,2; HYDROPHYLLACEAE: Phacelia hastata var. hastata^1,2. Comments: The paratype label describes the locality as only Chinook Pass, Wash., which is located on the Pierce and Yakima County line. Rozen (1958) reports the paratype as being collected in Pierce County. Discover Life and GBIF report the paratype as being collected in Yakima County. It is unclear which county is correct, so both counties are being presented here with preference given to Rozen (1958).

Panurgini

Genus Panurginus Nylander

114. Panurginus atriceps (Cresson, 1878). County records: Clark^1,2, Cowlitz^1,2,3, King^34,118, Skagit^1,2,3, Thurston⁸⁷, Whitman^1,2,3, Yakima^1,2,3. Seasonality: May^1,2,118, Jun^1,2,3,118, Jul^1,2,3,118, Aug^1,2,3 (2014³). Collections: BBSL, JRYA, NMNH, PWRC, SEMC. Floral records: ROSACEAE: Rubus ursinus¹¹⁸

115. Panurginus ineptus Cockerell, 1922. County records: Clallam³, Pierce^1,2,3,48, Skagit³. Seasonality: Jul^1,2,3,48, Aug^1,2,3 (2014³). Collections: AMNH, BBSL, JRYA, OSUC

116. † Panurginus nigrellus Crawford, 1926. County records: Klickitat⁷. Seasonality: Jun⁷ (1975⁷). Collections: WSUC

Perditini

Genus Perdita Smith

117. Perdita (Cockerellia) albipennis Cresson, 1868. Comments: Viereck et al. (1905) indicate that P. albipennis is present in Washington, but do not provide a locality.

118. Perdita (Cockerellia) lingualis Cockerell, 1896. County records: Whitman^1,2,3,8. Seasonality: Sep^1,2,3 (1982^1,2,3). Collections: BBSL, WSUC. Floral records: ASTERACEAE: Helianthus annuus⁸; GERANIACEAE: Geranium viscosissimum⁸; ROSACEAE: Rosa⁸

119. ‡ Perdita (Perdita) ciliata Timberlake, 1958. County records: Chelan^2,67,112. Seasonality: Aug^2,67 (1941^2,67,112). Collections: LACM. [= Perdita crassihirta Timberlake, 1968]. Holotype. USA, Washington, Chelan County, Wenatchee; 21 August 1941; J Roberds; LACM ENT 164669. Conservation status: Data Deficient (National Research Council 2007)

120. Perdita (Perdita) oregonensis Timberlake, 1929. County records: Benton⁷, Franklin⁶⁶. Seasonality: Sep⁶⁶, Oct⁷ (1994⁷). Collections: WSUC

121. Perdita (Perdita) salicis imperialis Cockerell, 1925. County records: Asotin⁸⁹, Benton⁷, Spokane⁸⁹, Walla Walla⁸⁹, Whitman⁸⁹. Seasonality: May^7,89, Jun⁸⁹, Jul⁸⁹ (1994⁷). Collections: WSUC

122. §‡ Perdita (Perdita) similis pascoensis Timberlake, 1958. County records: Franklin^1,2,3,66,112. Seasonality: Sep^1,2,3,66 (1904^1,2,3,66). Collections: NMNH. Holotype. USA, Washington, Franklin County, Pasco; 11 September 1904; ESG Titus; Type No. 64325, USNM ENT 00532871. Conservation status: Vulnerable (National Research Council 2007)

123. † Perdita (Perdita) zonalis Cresson, 1879. County records: Whitman^1,2,3. Seasonality: Sep^1,2,3 (1982^1,2,3)

124. ‡ Perdita (Pygoperdita) nevadensis nevadensis Cockerell, 1896. County records: Chelan^1,2,3,88, Spokane^1,2,3. Seasonality: Jul^1,2,3,88 (1949^1,2,88). Collections: BBSL, INHS, SEMC, UCRC

125. Perdita (Pygoperdita) wyomingensis Cockerell, 1922. County records: Whitman³. Seasonality: Jun³ (1962³). Collections: UCRC

125a. § Perdita (Pygoperdita) wyomingensis sculleni Timberlake, 1956. County records: Whitman^8,88, Yakima⁶. Seasonality: Jun⁸⁸, Jul^6,88 (2022⁶). Collections: WSDA, WSUC. Conservation status: Vulnerable (National Research Council 2007). Floral records: ASTERACEAE: Achillea millefolium⁸; ROSACEAE: Holodiscus discolor⁸

125b. † Perdita (Pygoperdita) wyomingensis segona Timberlake, 1956. County records: Benton^1,2, Spokane^1,2. Seasonality: May^1,2, Jun^1,2, Jul^1,2 (2015^1,2). Collections: BBSL

Apidae: Anthophorinae: Anthophorini

Genus Anthophora Latreille

126. Anthophora (Clisodon) terminalis Cresson, 1869. County records: Benton^1,2, Okanogan^1,2,3, Pierce^1,2,3,6, San Juan^{1,2,3,124,136}, Spokane^1,2, Thurston^1,2,118, Whatcom⁶, Whitman^1,2,3. Seasonality: Jun^1,2,3, Jul^1,2,3,6,118, Aug⁶ (2021^1,2). Collections: BBSL, iNaturalist, NMNH, PWRC, SEMC, WSDA. [= Podalirius syringae Cockerell, 1898]. Holotype. USA, Washington, Thurston County, Olympia; 2 July 1896; Type No. 20234, USNM ENT 00534169. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: CONVOLVULACEAE: Calystegia soldanella¹³⁶

127. Anthophora (Lophanthophora) affabilis Cresson, 1878. County records: Whitman³². Seasonality: Jun³² (2013³²). Conservation status: G5 – Secure globally (NatureServe 2024)

128. †§ Anthophora (Lophanthophora) neglecta Timberlake and Cockerell, 1936. County records: Benton^1,2,3. Seasonality: Apr^1,2,3 (1995^1,2,3). Collections: BBSL. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

129. Anthophora (Lophanthophora) pacifica Cresson, 1878. County records: Benton^1,2,3, Chelan^1,2,3, King^1,2, Kittitas^2,3, Okanogan^1,2,3, Spokane^1,2, Whitman^1,2,3,8,61, Yakima^1,2,3,121. Seasonality: Feb^1,2, Mar^1,2, Apr^1,2,3,61, May^1,2,3,121 (2022^1,2). Collections: BBSL, iNaturalist, INHS, SEMC, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: APIACEAE: Lomatium⁸; ASTERACEAE: Balsamorhiza sagittata⁸; FABACEAE: Astragalus columbianus³, A. sinuatus³; GROSSULARIACEAE: Ribes³, R. aureum⁸; LAMIACEAE: Salvia dorrii³; OLEACEAE; Syringa⁸; ROSACEAE: Malus domestica⁸, Prunus armeniaca⁸

130. Anthophora (Lophanthophora) porterae Cockerell, 1900. County records: Benton^1,2,3, Chelan¹³⁶, Garfield^1,2,3,46, Walla Walla^1,2, Whitman^1,2, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3 (2012^1,2). Collections: BBSL, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus³, A. columbianus³, A. speirocarpus³

131. Anthophora (Lophanthophora) ursina Cresson, 1869. County records: Adams³, Garfield^1,2,3,46, Okanogan^1,2,3,59, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,2,8, Yakima^2,121. Seasonality: Mar^1,2, Apr^1,2,3, May^1,2,3,121, Jun^1,2,3, Jul^1,2 (2015^1,2). Collections: BBSL, SEMC, UCRC, WSUC. [= Anthophora simillima Cresson, 1879]. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus³, Vicia villosa⁸; ROSACEAE: Rosa nutkana ssp. nutkana^3,59

132. Anthophora (Melea) bomboides Kirby, 1837. County records: Chelan^1,2,3, Clallam^1,2, Garfield^1,2,3,46, Island^2,3,106, Jefferson^1,2, King^1,2,106, Kittitas^1,2, Pierce^1,2,6, San Juan^{1,2,3,5,6,22,106,136}, Spokane^1,2, Thurston^1,2,106, Walla Walla^1,2, Whatcom^2,106, Whitman^8,106, Yakima^1,2,3,121. Seasonality: Apr^1,2, May^1,2,3,121, Jun^1,2,3,5,6, Jul^1,2,6, Aug^2,3,6 (2020^1,2,6). Collections: BBSL, iNaturalist, PMNH, PWRC, SEMC, UCRC, WSDA, WSUC. [= Anthophora sodalis Cresson, 1879]. [= Anthophora bomboides solitaria Ritsema, 1880]. [= Anthophora bomboides stanfordiana Cockerell, 1904]. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASPARAGACEAE: Brodiaea coronaria⁵; ASTERACEAE: Balsamorhiza³; BRASSICACEAE: Cakile maritima¹³⁶; CAPRIFOLIACEAE: Symphoricarpos albus¹³⁶; CONVOLVULACEAE: Calystegia soldanella¹³⁶; FABACEAE: Astragalus podolobus³; ROSACEAE: Rosa nutkana¹³⁶, Rubus bifrons¹³⁶

133. § Anthophora (Melea) occidentalis Cresson, 1869. County records: Chelan^1,2, King^1,2, Whitman^1,2, Yakima^1,2,106. Seasonality: Apr², May^1,2, Jun^1,2, Jul^1,2 (1982^1,2). Collections: SEMC. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

134. Anthophora (Micranthophora) albata Cresson, 1876. County records: Benton^1,2,107, Chelan¹⁰⁷, Douglas^2,3. Seasonality: Jun^1,2,107, Aug^2,107 (1995^1,2,107). Collections: BBSL, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

135. † Anthophora (Micranthophora) curta Provancher, 1895. County records: Walla Walla^1,2,107. Seasonality: Jun^1,2,107, Jul¹⁰⁷ (2012^1,2,107). Collections: BBSL. Conservation status: G5 – Secure globally (NatureServe 2024)

136. ‡ Anthophora (Micranthophora) exigua Cresson, 1879. County records: Adams⁷, Grant⁷, Kittitas^1,107. Seasonality: Jun⁷, Jul^1,107, Sep⁷, Aug⁷ (1949^1,107). Collections: SEMC, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

137. † Anthophora (Micranthophora) peritomae Cockerell, 1905. County records: Benton⁷. Seasonality: Aug⁷ (1994⁷). Collections: WSUC

138. Anthophora (Mystacanthophora) urbana Cresson, 1878. County records: Benton^1,2,3,71, Chelan^1,2, Douglas^1,2, Grant^1,2, Jefferson^1,2, Kittitas^1,2,3, Klickitat^1,2, Okanogan^1,2,3,59, Walla Walla^1,2,3,71, Whitman^2,3, Yakima¹²¹. Seasonality: Jun^1,2,3,121, Jul^1,2,3, Aug^1,2,3, Sep^1,2, Oct^1,2 (2021^1,2). Collections: BBSL, iNaturalist, SEMC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: HYDROPHYLLACEAE: Phacelia hastata³; PLANTAGINACEAE: Penstemon washingtonensis^3,59

139. § Anthophora (Pyganthophora) crotchii Cresson, 1878. County records: Adams^1,2,3, Benton^1,2, Franklin^1,2,3,118, Grant^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3, Yakima^2,121. Seasonality: Mar^1,2, Apr^1,2,3,121, May^{1,2,3,118,121}, Jun^1,2,3 (2022^1,2). Collections: AMNH, BBSL, iNaturalist, SEMC, UCRC. [= Anthophora washingtoni Cockerell, 1905]. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; T Kincaid. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

140. ‡ Anthophora (Pyganthophora) edwardsii Cresson, 1878. County records: Douglas³, Garfield⁴⁶, Walla Walla^1,2,3, Whitman^1,2,3, Yakima^1,2,3,121. Seasonality: Apr^1,2,121, May^1,2,3,121, Jun^1,2 (1937^1,2). Collections: SEMC, UCRC. Conservation status: G4 – Apparently Secure Globally (NatureServe 2024)

Genus Habropoda Smith

141. Habropoda cineraria (Smith, 1879). County records: Adams², Asotin², Benton^1,2,3, Chelan^1,2,3, Franklin^1,2, King¹, Kittitas^2,3, Spokane^1,2, Whitman^1,2,3,8, Yakima^1,2,3,121. Seasonality: Mar^1,2, Apr^1,2,3,121, May^1,2,3 (2015^1,2). Collections: BBSL, INHS, SEMC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: GROSSULARIACEAE: Ribes³, R. aureum⁸; LAMIACEAE; Salvia dorrii³; ROSACEAE: Malus domestica⁸, Prunus armeniaca⁸, Rosa⁸

142. † Habropoda cressonii (Dalla Torre, 1896). County records: Whitman². Seasonality: Apr² (1973²). Collections: SEMC

143. †§ Habropoda miserabilis (Cresson, 1878). County records: Jefferson^1,2, King^1,2, Okanogan^1,2,3, Pacific^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3 (2022^1,2). Collections: BBSL, iNaturalist, SEMC. Conservation status: G2 – Imperiled globally (NatureServe 2024)

144. Habropoda morrisoni (Cresson, 1878). County records: Benton^1,2,3, Franklin^1,2,118. Seasonality: Apr^1,2,3, May^1,2 (1995^1,2). Collections: BBSL, NMNH, SEMC. [= Emphoropsis floridana var. pascoensis Cockerell, 1878]. [= Habropoda floridana var. pascoensis Cockerell, 1878]. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; Type No. 58047, USNM ENT 00534175. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

Apinae: Apini

Genus Apis Linnaeus

145. * Apis mellifera Linnaeus, 1758. County records: Adams^1,2, Asotin^1,2,3, Benton^1,2,3,6,71, Chelan^1,2,3, Clallam^1,2,3,6, Clark^1,2,3, Columbia^1,2, Cowlitz^1,2,3, Douglas^1,2, Franklin^1,2,6, Garfield^1,2,46, Grant^1,2,3,6, Grays Harbor^1,2,6, Island^1,2, Jefferson^1,2,6, King^1,2,3,6, Kitsap^1,2,6, Kittitas^1,2, Klickitat^1,2,3, Lewis^1,2,3, Lincoln^1,2, Mason^1,2,3, Okanogan^1,2,3, Pacific^1,2,3,6, Pierce^1,2,3,6, San Juan^{1,2,3,5,6,124}, Skagit^1,2,3,6,10, Skamania^1,2,3, Snohomish^1,2,3,6, Spokane^1,2,3, Stevens^1,2,3, Thurston^{1,2,3,6,130,133}, Wahkiakum^1,2,3, Walla Walla^1,2,3,6,71, Whatcom^1,2,3,6,33, Whitman^1,2,3, Yakima^1,2,3,6. Seasonality: Jan^1,2, Feb^1,2, Mar^1,2,3, Apr^1,2,3, May^{1,2,3,5,6,133}, Jun^{1,2,3,5,6,133}, Jul^1,2,3,6,133, Aug^1,2,3,6,33, Sep^1,2,3,6, Oct^1,2,3,6, Nov^1,2,6 (2022^1,2,6). Collections: BBSL, EMEC, FMNH iNaturalist, JRYA, NMNH, OSUC, PWRC, SEMC, UNM, WSDA. Floral records: APIACEAE: Heracleum sphondylium ssp. Montanum⁵; APOCYNACEAE: Apocynum androsaemifolium¹³³; ASPARAGACEAE: Camassia quamash¹³³, Triteleia hyacinthina¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Crepis capillaris¹³³, Cirsium arvense¹³³, Eriophyllum lanatum¹³³, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³, Solidago simplex¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus^5,133; ERICACEAE: Arctostaphylos uva-ursi¹³³; FABACEAE: Lupinus albicaulis¹³³, L. bicolor¹³³, L. lepidus¹³³, Trifolium repens¹³³, Vicia hirsuta¹³³, V. sativa¹³³; HYPERICACEAE: Hypericum perforatum¹³³; LAMIACEAE: Salvia dorrii³; PLANTAGINACEAE: Collinsia grandiflora¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; POLEMONIACEAE: Gilia capitata¹³³. Comments: Due to its ubiquitous use in commercial agriculture, it is assumed that A. mellifera occurs in Ferry and Pend Oreille counties as well.

Bombini

Genus Bombus Latreille

146. †§ Bombus (Alpinobombus) kirbiellus Curtis, 1835. County records: Okanogan^1,2,3. Seasonality: Aug^1,2,3 (2019^1,2,3). Collections: BOMBUS, iNaturalist, NMNH. Conservation status: Data Deficient (Hatfield et al. 2016a); G4 – Apparently Secure globally, S1 – Critically Imperiled in Washington (NatureServe 2024)

147. Bombus (Bombias) nevadensis Cresson, 1874. County records: Adams^1,2, Asotin^1,2,3, Benton^1,2,3, Chelan^1,2,3, Clark^1,2, Columbia^1,2, Douglas^1,2, Ferry^1,2, Franklin^1,2, Garfield^1,2,3,46, Grant^1,2,3, Island^1,2,3, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2, Klickitat^1,2,3, Lincoln^1,2, Okanogan^1,2, Pend Oreille^1,2, Pierce^1,2, San Juan^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Thurston^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2,3, Oct^1,2 (2021^1,2). Collections: AMNH, BBSL, BOMBUS, CNC, EMEC, iNaturalist, INHS, NMNH, PMNH, UCRC, WSUC. Conservation status: Least Concern (Hatfield et al. 2015a); G4 – Apparently Secure globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Balsamorhiza sagittata⁸, Cirsium vulgare⁸, Solidago⁸; DIPSACACEAE: Dipsacus fullonum⁸; FABACEAE: Astragulus⁸, Medicago sativa⁸, Trifolium pratense³, T. repens⁸, Vicia villosa⁸; HYDROPHYLLACEAE: Phacelia⁸; LAMIACEAE: Agastache urticifolia⁸; PLANTAGINACEAE: Penstemon⁸; ROSACEAE: Malus domestica⁸

148. § Bombus (Bombus) occidentalis Greene, 1858. County records: Asotin^1,2,3, Benton^1,2,3, Chelan^1,2,3, Clallam^1,2,3,124, Columbia^1,2,3, Cowlitz^1,3, Douglas^1,2, Ferry^1,2,3, Franklin^1,2, Garfield^1,2,3,46, Grant^1,2,3, Grays Harbor^1,2,3, Island^1,2,3,6, Jefferson^1,2,3,124, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,3, Lewis^1,2,3, Lincoln^1,2,3, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3, Pend Oreille^1,2,3, Pierce^1,2,3, San Juan^1,2,3, Skagit^1,2,3, Skamania^1,2,3, Snohomish^1,2,3,6, Spokane^1,2,3, Stevens^1,2,3, Thurston^1,2,3,130, Wahkiakum^1,2,3, Walla Walla^1,2,3, Whatcom^1,2,3,6, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Jan², Feb^1,2, Mar^1,2, Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2,3,6, Aug^1,2,3,6, Sep^1,2,3, Oct^1,2, Dec^1,2 (2021^1,2,6). Collections: AMNH, BBSL, BOMBUS, CNC, CSCA, EMEC, FMNH, iNaturalist, INHS, JRYA, LACM, NMNH, PMNH, SEMC, TAMU, UCMC, UCRC, WSDA, WSUC. Conservation status: Vulnerable (National Research Council 2007; Hatfield et al. 2015b); G3 – Vulnerable globally, S2 – Imperiled in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Arnica cordifolia⁵⁹, Balsamorhiza sagittata⁸, Cirsium vulgare⁸, Erigeron speciosus⁵⁹; FABACEAE: Lupinus polyphyllus⁸; Medicago sativa⁸, Trifolium repens⁸, Vicia villosa⁸; HYDROPHYLLACEAE: Phacelia⁸; IRIDACEAE: Sisyrinchium⁸; ONAGRACEAE: Chamerion angustifolium ssp. Angustifolium⁸; PLANTAGINACEAE: Penstemon⁸; RANUNCULACEAE: Aconitum columbianum⁸; ROSACEAE: Malus domestica⁸, Rosa⁸, Rubus parviflorus⁸

149. Bombus (Cullumanobombus) griseocollis (DeGeer, 1773). County records: Adams^1,2, Asotin^1,2, Benton^1,2,3, Chelan^1,2,3, Clark^1,2,3,124, Douglas^1,2, Franklin^1,2,3, Garfield^1,2,46, Grant^1,2,3, Kittitas^1,2, Klickitat^1,2, Lincoln^1,2, Okanogan^1,2,3, Pierce³, Spokane^1,2,3, Thurston¹³⁰, Walla Walla^1,2,3,71, Whitman^1,2,3,6,8, Yakima^1,2,3. Seasonality: Jan^1,2, Apr^1,2,3, May^1,2,3,6, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2,3, Oct^1,2 (2022^1,2). Collections: BBSL, BOMBUS, BugGuide, EMEC, iNaturalist, INHS, LACM, NMNH, UCDC, UCRC, WSDA, WSUC. Conservation status: Least Concern (Hatfield et al. 2015d); G5 – Secure globally, S5 – Secure in Washington (NatureServe 2024). Floral records: ASTERACEAE: Balsamorhiza sagittata⁸, Helianthus annuus⁸, Solidago⁸; FABACEAE: Lupinus polyphyllus⁸, Medicago sativa⁸, Vicia villosa⁸; HYDROPHYLLACEAE: Phacelia⁸; IRIDACEAE: Sisyrinchium⁸; ONAGRACEAE: Chamerion angustifolium ssp. Angustifolium⁸; PLANTAGINACEAE: Penstemon⁸; ROSACEAE: Rosa⁸

150. § Bombus (Cullumanobombus) morrisoni Cresson, 1878. County records: Adams^1,2, Asotin^2,3, Benton^1,2, Chelan^1,2,3, Franklin^1,2, Grant^1,2,3, Grays Harbor^1,2, Kittitas^1,2,3, Klickitat^1,2,3, Okanogan^1,2,3,59, Pierce^1,2,3, Spokane^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3, Yakima^1,2. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2, Jul^1,2,3, Aug^1,2,3, Sep¹, Oct¹ (2021^1,2). Collections: AMNH, BBSL, iNaturalist, INHS, NMNH, UCMC. Conservation status: Vulnerable (Hatfield et al. 2014a); G3 – Vulnerable globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: FABACEAE: Trifolium pratense³; PLANTAGINACEAE: Penstemon washingtonensis⁵⁹

151. Bombus (Cullumanobombus) rufocinctus Cresson, 1863. County records: Asotin^1,2,3, Benton^1,2,3, Chelan^1,2,3, Clallam^1,2,3, Clark^1,2,3, Columbia^1,2,3, Douglas^1,2, Ferry^1,2,3, Garfield^1,2,3, Island¹²⁴, Jefferson^1,2, Kittitas^1,2,3, Klickitat^1,2, Lewis^1,2,4, Lincoln^1,2,3, Mason^1,2, Okanogan^1,2,3,59, Pend Oreille^1,2,3, Pierce^1,2,3, San Juan^1,2,3,5,124, Skamania^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Thurston¹³³, Walla Walla^1,2, Whatcom^1,2,3, Whitman^1,2,3,6,8, Yakima^1,2. Seasonality: May^{1,2,3,4,5,133}, Jun^1,2,3,5,133, Jul^1,2,3,5,6, Aug^1,2,3,5, Sep^1,2,3, Oct^1,2,3 (2021^1,2). Collections: BBSL, BOMBUS, BugGuide, EMEC, FMNH, iNaturalist, INHS, JRYA, LACM, PCYU, PMNH, PWRC, SEMC, UCRC, WSDA, WSUC. Conservation status: Least Concern (Hatfield et al. 2015e); G5 – Secure globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Cirsium arvense³, Erigeron speciosus^3,59, Eriophyllum lanatum¹³³, Crepis capillaris⁵, Jacobaea vulgaris⁵, Solidago simplex¹³³; GERANIACEAE: Geranium viscosissimum⁸; HYDROPHYLLACEAE: Phacelia^3,5,8, P. hastata³; IRIDACEAE: Sisyrinchium⁸; ONAGRACEAE: Chamerion angustifolium ssp. Angustifolium⁸; ROSACEAE: Rosa nutkana⁵, Rubus ulmifolius⁵, R. ursinus⁵

152. § Bombus (Psithyrus) flavidus Eversmann, 1852. County records: Chelan^1,2,3, Clallam^1,2,3, Columbia^1,2, Grays Harbor^1,2,3, Island^2,3, Jefferson^1,2,3, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Mason^1,2, Okanogan^1,2,3,59, Pacific^1,2, Pend Oreille^1,2, Pierce^1,2,3, San Juan^1,2,3,124, Skagit^1,2,3, Skamania^1,2,3, Snohomish^1,2, Thurston^1,2, Whatcom^1,2.3,4, Whitman^1,2,3, Yakima^1,2. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2,3,4, Aug^1,2,3, Sep^1,2,3, Oct^1,2 (2021^1,2). Collections: BBSL, BugGuide, CNC, LACM, NMNH, PMNH, PWRC, SEMC, TAMU, UCRC, WSDA. [= Bombus fernaldae (Franklin, 1911)]. [= Psithyrus tricolor Franklin, 1911]. Conservation status: Data Deficient (Hatfield et al. 2016d); G5 – Secure Globally, S3 – Vulnerable in Washington (NatureServe 2024). Floral records: ASTERACEAE: Centaurea³, Cirsium³; BRASSICACEAE: Smelowskia calycina^3,59

153. § Bombus (Psithyrus) insularis (Smith, 1861). County records: Asotin^1,2,3, Chelan^1,2,3, Clallam^1,2, Clark^1,2, Columbia^1,2,3, Ferry^1,2, Garfield^1,2,3, Grays Harbor^1,2,3, Jefferson^1,2,3, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lewis^1,2, Lincoln^1,2,3, Mason^1,2,3, Okanogan^1,2,3,59, Pend Oreille^1,2,3, Pierce^1,2,3, San Juan^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Whatcom^1,2,3, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Jan^1,2, Mar^1,2, Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2,3, Oct^1,2 (2020^1,2). Collections: AMNH, BBSL, BOMBUS, CNC, EMEC, iNaturalist, INHS, JRYA, LACM, NMNH, NMSU, OSUC, PMNH, SEMC, UCRC, WSUC. Conservation status: Least Concern (Hatfield et al. 2014b); G3 – Vulnerable globally, S5 – Secure in Washington (NatureServe 2024). Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Agoseris glauca var. dasycephala⁵⁹, Anaphalis margaritacea⁵⁹, Cirsium arvense³, C. hookerianum⁵⁹, C. vulgare⁵⁹, Erigeron speciosus⁵⁹, Microseris nutans⁵⁹, Senecio triangularis⁵⁹, Taraxacum officinale^3,59; BRASSICACEAE: Smelowskia calycina⁵⁹; CRASSULACEAE: Sedum lanceolatum⁵⁹; DIPSACACEAE: Dipsacus fullonum⁸; FABACEAE: Melilotus albus⁵⁹, Trifolium repens³, Vicia³; LAMIACEAE: Agastache urticifolia⁸; ONAGRACEAE: Chamerion angustifolium ssp. Angustifolium⁸, Epilobium³; PLANTAGINACEAE: Penstemon confertus⁵⁹, P. washingtonensis⁵⁹

154. †§ Bombus (Psithyrus) suckleyi Greene, 1860. County records: Chelan^1,2, Clallam^1,2, Columbia^1,2, Douglas^1,2, Ferry^1,2, Jefferson^1,2,3, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2, Lewis^1,2,3, Mason^1,2,3, Pend Oreille^1,2,3, Pierce^1,2,3, San Juan^1,2,3, Skamania^1,2, Snohomish^1,2, Spokane^1,2,3, Stevens^1,2,3, Thurston^1,2,3, Walla Walla^1,2, Whitman^1,2,3, Yakima^1,2. Seasonality: Jan¹, Apr¹, May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2,3 (1998^1,2). Collections: AMNH, BBSL, CNC, EMEC, FMNH, INHS, LACM, NMNH, PMNH, SEMC, UCRC, WSUC. Conservation status: Critically Endangered (Hatfield et al. 2015f); G2 – Imperiled globally, S1 – Critically Imperiled in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Senecio⁸; IRIDACEAE: Sisyrinchium⁸; LAMIACEAE: Agastache urticifolia⁸; ONAGRACEAE: Chamerion angustifolium ssp. Angustifolium⁸

155. § Bombus (Pyrobombus) caliginosus (Frison, 1927). County records: Clallam^1,2,3,124, Clark^1,2, Cowlitz^1,2,3, Grays Harbor^1,2,3,6,70, Jefferson^1,2,3, King^2,3, Kitsap^1,2,3, Lewis^1,2,3, Mason^1,2,3, Pacific^1,2,3,6, Pierce^1,2,3, San Juan^2,3, Skamania^1,2,3, Thurston^1,2,3,6,133, Whatcom^1,2,3. Seasonality: May^1,2,133, Jun^1,2,133, Jul^1,2,3,6, Aug^1,2,3,6, Sep⁶ (2021⁶). Collections: BBSL, BOMBUS, EMEC, iNaturalist, INHS, JRYA, LACM, NMNH, PMNH, SEMC, WSDA. Conservation status: Vulnerable (Hatfield et al. 2014c); G2 – Imperiled globally, S3 – Vulnerable in Washington (NatureServe 2024). Floral records: ASTERACEAE: Microseris laciniata¹³³; CAPRIFOLIACEAE: Symphoricarpos albus¹³³; FABACEAE: Lathyrus odoratus³, Lupinus albicaulis¹³³; LAMIACEAE: Prunella vulgaris¹³³

156. Bombus (Pyrobombus) centralis Cresson, 1864. County records: Adams^1,2,3, Asotin^1,2,3, Benton^1,2,3, Chelan^1,2,3, Columbia^1,2, Douglas^1,2, Ferry^1,2,3, Garfield^1,2,3,46, Grant^1,2,3, King^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lincoln^1,2, Mason^1,2,3, Okanogan^1,2,3,59, Pend Oreille^1,2, San Juan^1,2,3, Skagit^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3,6,8, Yakima^1,2,3. Seasonality: Mar^1,2,3, Apr^1,2,3, May^1,2,3, Jun^1,2,3,6, Jul^1,2,3, Aug^1,2, Sep^1,2, Oct^1,2, Nov^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, EMEC, iNaturalist, INHS, NMNH, PMNH, PWRC, SEMC, UCRC, WSDA, WSUC. Conservation status: Least Concern (Hatfield et al. 2014d); G5 – Secure globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Anaphalis margaritacea⁸, Balsamorhiza sagittata⁸, Erigeron speciosus⁵⁹, Rudbeckia occidentalis⁸; BORAGINACEAE: Mertensia paniculata⁸; CAPRIFOLIACEAE: Lonicera³, Symphoricarpos albus³; DIPSACACEAE: Dipsacus fullonum⁸; FABACEAE: Astragalus sinuatus³, Lupinus polyphyllus⁸, L. sericeus^3,59, Trifolium repens⁸, Vicia villosa⁸; GERANIACEAE: Geranium viscosissimum⁸; HYDROPHYLLACEAE: Phacelia hastata³, P. leptosepala⁵⁹; IRIDACEAE: Sisyrinchium⁸; LAMIACEAE: Agastache urticifolia⁸; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium⁸, Clarkia pulchella³, Epilobium³; OROBANCHACEAE: Orthocarpus tenuifolius^3,59; PLANTAGINACEAE: Collinsia parviflora⁸, Penstemon⁸, P. confertus^3,59, P. washingtonensis⁵⁹; ROSACEAE: Malus domestica⁸, Rosa⁸, R. nutkana ssp. nutkana⁵⁹, Rubus parviflorus⁸

157. Bombus (Pyrobombus) flavifrons Cresson, 1864. County records: Asotin^1,2,3, Chelan^1,2,3,124, Clallam^1,2,3,47,124, Clark^1,2,3, Columbia^1,2,3, Cowlitz^1,2, Ferry^1,2, Garfield^1,2, Grays Harbor^1,2,3,6,70, Island^1,2,3,124, Jefferson^1,2,3,47,124, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Lewis^1,2,3,47, Lincoln^1,2, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2, Pend Oreille^1,2, Pierce^1,2,3,47, San Juan^{1,2,3,5,6,47,124,136}, Skagit^{1,2,3,6,10,47,70,124}, Skamania^1,2,3, Snohomish^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Thurston^{1,2,3,6,130,133}, Wahkiakum^1,2, Walla Walla^1,2,3, Whatcom^{1,2,3,6,47,124}, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Jan^1,2, Feb^1,2, Mar^1,2, Apr^1,2,3,5, May^1,2,3,5,133, Jun^1,2,3,6,133, Jul^{1,2,3,5,6,47,133}, Aug^1,2,3,6,47, Sep^1,2,3, Nov^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, CNC, EMEC, iNaturalist, INHS, JRYA, LACM, NMNH, OSUC, PMNH, PWRC, SEMC, UCRC, WSDA, WSUC. Conservation status: Least Concern (Hatfield et al. 2015g); G5 – Secure globally, S5 – Secure in Washington (NatureServe 2024). Floral records: ASTERACEAE: Balsamorhiza deltoidea¹³³, Cirsium arvense^8,133, Erigeron speciosus⁵⁹, Eriophyllum lanatum¹³³, Helianthus annuus⁸, Microseris nutans⁵⁹, Solidago simplex¹³³, Taraxacum officinale^5,136; BORAGINACEAE: Mertensia³; CAMPANULACEAE: Campanula rotundifolia¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus^5,59,133,136; CARYOPHYLLACEAE: Cerastium arvense¹³³; DIPSACACEAE: Dipsacus fullonum⁸; ERICACEAE: Gaultheria shallon³, Rhododendron⁵; FABACEAE: Astragalus miser var. serotinus⁵⁹, Lathyrus japonicus¹³⁶, L. nevadensis⁵, L. odoratus³, Lupinus albicaulis¹³³, L. lepidus¹³³, L. littoralis¹³⁶, Trifolium pratense¹³³, T. repens^3,5,59, Vicia americana¹³³, V. sativa¹³³, V. villosa⁸; GERANIACEAE: Geranium dissectum¹³³; GROSSULARIACEAE: Ribes divaricatum¹³⁶; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; HYPERICACEAE: Hypericum perforatum¹³³; IRIDACEAE: Sisyrinchium⁸; LAMIACEAE: Agastache urticifolia⁸, Prunella vulgaris¹³³; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium^3,8; OROBRANCHACEAE: Castilleja⁸, C. miniata⁵⁹, Parentucellia viscosa¹³³; PLANTAGINACEAE: Collinsia grandiflora¹³³, Penstemon⁸, P. confertus⁵⁹, P. washingtonensis⁵⁹; POLEMONIACEAE: Gilia capitata¹³³; RANUNCULACEAE: Delphinium nuttallianum^59,133; ROSACEAE: Potentilla gracilis¹³³, Rubus bifrons¹³⁶

158. § Bombus (Pyrobombus) frigidus Smith, 1854. County records: Chelan^1,2,3, Clallam^1,2, Cowlitz^1,2, Jefferson^1,2, King^1,2,3, Kitsap^1,2,3, Okanogan^1,2,3, Thurston^1,2, Whatcom^1,2, Yakima^1,2. Seasonality: Jun^1,2, Jul^1,2,3, Aug^1,2,3, Sep^1,2,3 (2010^1,2). Collections: BBSL, CNC, NMNH, SEMC. Conservation status: Least Concern (Hatfield et al. 2014e); G5 – Secure globally, S2 – Imperiled in Washington (NatureServe 2024). Floral records: CAPRIFOLIACEAE: Symphoricarpos albus³; FABACEAE: Lupinus³; ONAGRACEAE: Epilobium³

159. Bombus (Pyrobombus) huntii Greene, 1860. County records: Adams^1,2,3, Asotin^1,2, Benton^1,2,3, Chelan^1,2,3, Douglas^1,2,3, Ferry^1,2,3, Garfield⁴⁶, Grant^1,2,3, King^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lincoln^1,2,3, Okanogan^1,2,3, Pierce^1,2,3, Spokane^1,2,3, Stevens^1,2, Thurston^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Mar^1,2, Apr^1,2,3, May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2, Oct^1,2,3, Nov^1,2 (2022^1,2). Collections: AMNH, BOMBUS, BugGuide, EMEC, iNaturalist, INHS, LACM, NMNH, SEMC, UCRC. Conservation status: Least Concern (Hatfield et al. 2015h); G5 – Secure globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: CAPRIFOLIACEAE: Symphoricarpos albus³

160. * Bombus (Pyrobombus) impatiens Cresson, 1863. County records: King^1,2, Skagit^1,2, Whatcom^1,2,3,6,33. Seasonality: Apr^1,2,33, May^1,2,6,33, Jul^1,2,6, Aug^1,2,6,33, Sep^1,6, Oct^1,2,3,6, Dec^1,2 (2022^1,2). Collections: BOMBUS, BugGuide, iNaturalist, WSDA. Conservation status: Least Concern (Hatfield et al. 2014f); G5 – Secure globally (NatureServe 2024)

161. § Bombus (Pyrobombus) lapponicus sylvicola Kirby, 1837. County records: Chelan^1,2,3,124, Clallam^{1,2,3,47,69,124}, Jefferson^{1,2,3,47,69,124}, King^1,2,3, Kittitas^1,2, Lewis^1,2,47,124, Lincoln^1,2, Mason^1,2,3, Okanogan^1,2, Pierce^1,2,3,47,124, San Juan^1,2,3,124, Skagit^1,2,3,47,124, Whatcom^1,2,3,47, Yakima^1,2, Seasonality: Jun^1,2, Jul^1,2,3,47, Aug^1,2,3,47, Sep^1,2,3 (2018^1,2). Collections: BBSL, BOMBUS, iNaturalist, JRYA, LACM, NMNH, OSUC, PMNH, PWRC, UCDC. Conservation status: Least Concern (Hatfield et al. 2015j); G5 – Secure globally, S3 – Vulnerable in Washington (NatureServe 2024)

162. Bombus (Pyrobombus) melanopygus Nylander, 1848. County records: Chelan^1,2,3,124, Clallam^1,2.3,47,124, Clark^1,2,3, Cowlitz^1,2, Douglas^1,2, Ferry^1,2, Franklin^1,2, Grays Harbor^1,2,3, Island^1,2, Jefferson^1,2,3,47,124, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2, Lewis^1,2,3, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3, Pend Oreille^1,2,3, Pierce^1,2,3,47,124, San Juan^{1,2,3,5,6,22,47,124,136}, Skagit^1,2,3,10,124, Skamania^1,2,3, Snohomish^1,2,3,6, Spokane^1,2,3, Thurston^{1,2,3,130,133}, Walla Walla^1,2,3, Whatcom^{1,2,3,6,33,47,124}, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Jan^1,2, Feb^1,2, Mar^1,2, Apr^1,2,3,5,133, May^{1,2,3,5,33,133}, Jun^1,2,3,5,133, Jul^1,2,3,6,47, Aug^1,2,3,6,47, Sep^1,2, Oct^1,2, Nov^1,2, Dec^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, CNC, EMEC, FMNH, iNaturalist, INHS, LACM, NMNH, OSUC, PMNH, PWRC, SEMC, UCDC, UCRC, WSDA. Conservation status: Least Concern (Hatfield et al. 2014g); G5 – Secure globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Achillea millefolium^59,133, Anaphalis margaritacea⁵⁹, Erigeron speciosus⁵⁹, Grindelia integrifolia⁵, Hypochaeris radicata¹³³, Microseris nutans⁵⁹, Senecio integerrimus^3,59, Solidago simplex¹³³, Taraxacum officinale^5,59; BORAGINACEAE: Myosotis laxa⁵⁹; CAPRIFOLIACEAE: Symphoricarpos albus¹³⁶; CARYOPHYLLACEAE: Eremogone capillaris var. capillaris⁵⁹; CUCURBITACEAE: Marah oregana⁵; ERICACEAE: Arctostaphylos uva-ursi¹³³, Heather⁵, Rhododendron⁵; FABACEAE: Lupinus albicaulis¹³³, L. lepidus¹³³, Trifolium repens^3,59, Vicia sativa¹³³; GROSSULARIACEAE: Ribes divaricatum⁵; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; OROBRANCHACEAE: Castilleja miniata⁵⁹, Parentucellia viscosa¹³³; PLANTAGINACEAE: Collinsia grandiflora¹³³, Penstemon confertus⁵⁹; ROSACEAE: Rubus^3,59; VALERIANACEAE: Plectritis congesta⁵; VIOLACEAE: Viola adunca¹³³

163. Bombus (Pyrobombus) mixtus Cresson, 1879. County records: Asotin^1,2,3, Chelan^1,2,3,124, Clallam^1,2,3,47,124, Clark^1,2,3, Columbia^1,2,3, Cowlitz^1,2,3, Douglas^1,2, Ferry^1,2,3, Garfield^1,2, Grays Harbor^1,2,3,6,70, Island^1,2,3,6, Jefferson^1,2,3,47,124, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lewis^1,2,3,124, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3, Pend Oreille^1,2,3, Pierce^1,2,3,6,47, San Juan^{1,2,3,5,6,22,47,124,136}, Skagit^{1,2,3,6,10,47,70,124}, Skamania^1,2, Snohomish^1,2,3,6, Spokane^1,2,3, Stevens^1,2,3, Thurston^{1,2,3,6,130,133}, Wahkiakum^1,2,3, Walla Walla^1,2,3, Whatcom^{1,2,3,6,47,124}, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Jan^1,2, Feb^1,2, Mar^1,2, Apr^1,2,5,133, May^1,2,3,5,133, Jun^{1,2,3,5,6,133}, Jul^{1,2,3,5,6,47,133}, Aug^1,2,3,5,6,47, Sep^1,2,6, Oct^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, CNC, CSCA, EMEC, iNaturalist, INHS, JRYA, LACM, NMNH, OSUC, PMNH, PWRC, SEMC, UCRC, WFBM, WSDA, WSUC. Conservation status: Least Concern (Hatfield et al. 2014h); G5 – Secure globally, S5 – Secure in Washington (NatureServe 2024). Floral records: APOCYNACEAE: Apocynum androsaemifolium¹³³; ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Achillea millefolium⁵⁹, Arnica cordifolia^8,59, Balsamorhiza deltoidea¹³³, Cirsium arvense¹³³, Crepis capillaris¹³³, Erigeron speciosus⁵⁹, Eriophyllum lanatum¹³³, Hypochaeris radicata¹³³, Jacobaea vulgaris⁵, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Rudbeckia occidentalis⁸, Senecio jacobaea¹³³, S. triangularis⁵⁹, Solidago simplex¹³³, Taraxacum officinale^5,59,136; BORAGINACEAE: Mertensia³, M. paniculata⁸; BRASSICACEAE: Brassica rapa⁵, Cakile maritima¹³⁶; CAPRIFOLIACEAE: Lonicera involucrata^3,59, Plectritis congesta¹³³, Symphoricarpos albus^133,136; ERICACEAE: Arctostaphylos uva-ursi¹³³, Phyllodoce empetriformis⁵⁹; FABACEAE: Astragalus miser var. serotinus⁵⁹, Lupinus⁵⁹, L. albicaulis¹³³, L. bicolor¹³³, L. lepidus¹³³, L. littoralis¹³⁶, L. polyphyllus⁸, Vicia hirsuta¹³³, V. sativa¹³³; GERANIACEAE: Geranium dissectum¹³³, G. molle^5,136; GROSSULARIACEAE: Ribes³, R. divaricatum^5,136; HYDROPHYLLACEAE: Phacelia⁸, P. leptosepala⁵⁹; HYPERICACEAE: Hypericum perforatum¹³³; IRIDACEAE: Sisyrinchium⁸; LAMIACEAE: Prunella vulgaris¹³³; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium⁸, Clarkia amoena¹³³; OROBRANCHACEAE: Pedicularis bracteosa var. latifolia⁵⁹; PAPAVERACEAE: Eschscholzia californica⁵; PLANTAGINACEAE: Collinsia grandiflora¹³³, C. parviflora⁸, Penstemon confertus⁵⁹, P. washingtonensis⁵⁹; POLEMONIACEAE: Gilia capitata¹³³; RANUNCULACEAE: Delphinium nuttallianum⁵⁹; ROSACEAE: Potentilla gracilis¹³³, Rosa nutkana ssp. nutkana⁵⁹, Rubus⁵⁹, R. bifrons¹³⁶, R. ulmifolius⁵, R. parviflorus⁵⁹, R. ursinus⁵; VALERIANACEAE: Plectritis congesta⁵

164. Bombus (Pyrobombus) sitkensis Nylander, 1848. County records: Chelan^1,2,3, Clallam^1,2,3, Clark^1,2,3, Columbia^1,2,3, Cowlitz^1,2, Grant³, Grays Harbor^1,2,3, Island^1,2,3, Jefferson^1,2,3, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Lewis^1,2,3, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3, Pend Oreille^1,2, Pierce^1,2,3,6, San Juan^{1,2,3,6,22,124,136}, Skagit^1,2,3,6,10, Skamania^1,2, Snohomish^1,2,3, Spokane^1,2, Thurston^{1,2,3,6,130,133}, Whatcom^1,2,3,6, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Jan^1,2, Mar^1,2, Apr^1,2, May^1,2,3,133, Jun^1,2,3,6,133, Jul^1,2,3,6,133, Aug^1,2,3,6, Sep^1,2,6, Oct^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, CNC, CSCA, EMEC, FMNH, iNaturalist, INHS, JRYA, LACM, NMNH, OSUC, PMNH, PWRC, SEMC, UCDC, UCRC, WSDA. Conservation status: Least Concern (Hatfield et al. 2015i); G4 – Apparently Secure globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Cirsium arvense¹³³, Hypochaeris radicata¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus^133,136; FABACEAE: Lathyrus³, Lupinus³, L. albicauilis¹³³, Vicia hirsuta¹³⁶; GROSSULARIACEAE: Ribes divaricatum¹³⁶; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; LAMIACEAE: Agastache³, Prunella vulgaris¹³³; OROBANCHACEAE: Parentucellia viscosa¹³³; PRIMULACEAE: Dodecatheon hendersonii¹³³; RANUNCULACEAE: Delphinium nuttallii¹³³

165. § Bombus (Pyrobombus) vagans Smith, 1854. County records: Chelan^1,2, Ferry^1,2, Lincoln^1,2, Okanogan^1,2,3, Pend Oreille^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Thurston¹³³, Walla Walla^1,2,3, Whitman^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3,133, Jun^1,2,3, Jul^1,2,3, Aug^1,2, Sep^1,2, Oct^1,2 (2021^1,2). Collections: BBSL, BOMBUS, BugGuide, EMEC, iNaturalist, UCRC, WSUC. Conservation status: Least Concern (Hatfield et al. 2015k); G4 – Apparently Secure globally, S2 – Imperiled in Washington (NatureServe 2024). Floral records: CAPRIFOLIACEAE: Plectritis congesta¹³³; IRIDACEAE: Sisyrinchium⁸

166. Bombus (Pyrobombus) vancouverensis Cresson, 1879. County records: Asotin^1,2,3, Benton^1,2,3, Chelan^1,2,3,124, Clallam^1,2,3,124, Columbia^1,2,3, Douglas^1,2,3, Ferry^1,2,3, Garfield^1,2,3,46, Grant^1,2,3, Jefferson^1,2,3,124, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lewis^1,2,124, Lincoln^1,2,3, Mason^1,2,3, Okanogan^1,2,3,59, Pend Oreille^1,2,3, Pierce^1,2,3,124, San Juan^{1,2,3,5,6,22,124,136}, Skagit¹²⁴, Skamania^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Thurston^1,2,3, Walla Walla^1,2,3, Whatcom^1,2,3,124, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Jan^1,2, Mar^1,2, Apr^1,2,3, May^1,2,3,5, Jun^1,2,3, Jul^1,2,3,5,6, Aug^1,2,3,5,6, Sep^1,2, Oct^1,2 (2019^1,2,6). Collections: AMNH, BBSL, BOMBUS, CNC, CSCA, EMEC, FMNH, iNaturalist, INHS, JRYA, LACM, NMNH, PMNH, PWRC, OSUC, SEMC, UCRC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Agoseris glauca var. dasycephala⁵⁹, Anaphalis margaritacea^8,59, Arnica cordifolia⁵⁹, A. sororia⁵⁹, Cirsium arvense⁸, Erigeron speciosus⁵⁹, Hypochaeris radicata¹³⁶, Jacobaea vulgaris⁵, Microseris nutans⁵⁹, Rudbeckia occidentalis⁸, Senecio integerrimus⁵⁹, S. triangularis⁵⁹, Taraxacum officinale^59,136; BRASSICACEAE: Sisymbrium altissimum⁵⁹; CAPRIFOLIACEAE: Symphoricarpos albus^59,136; CUCURBITACEAE: Marah oregana⁵; FABACEAE: Astragalus miser var. serotinus⁵⁹, Lupinus⁵⁹, L. littoralis¹³⁶, L. polyphyllus⁸, L. sericeus⁵⁹, Melilotus albus⁵⁹, Trifolium pratense⁵⁹, T. repens⁵⁹, Vicia villosa⁸; GERANIACEAE: Geranium viscosissimum var. viscosissimum⁵⁹; GROSSULARIACEAE: Ribes divaricatum¹³⁶; HYDROPHYLLACEAE: Phacelia⁸, P. leptosepala⁵⁹; IRIDACEAE: Sisyrinchium⁸; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium^8,59; OROBANCHACEAE: Orthocarpus tenuifolius⁵⁹; PLANTAGINACEAE: Collinsia parviflora⁸, Penstemon⁸, P. confertus⁵⁹, P. washingtonensis⁵⁹; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹; ROSACEAE: Potentilla gracilis⁵⁹, Rubus bifrons¹³⁶, L. parviflorus⁵⁹

166a. Bombus (Pyrobombus) vancouverensis nearcticus Handlirsch, 1888. County records: Chelan^1,2, Kittitas^1,2, Klickitat^1,2, Lewis⁶⁸, Okanogan^1,2, Pend Oreille^1,2, Pierce^1,2,68, Skamania^1,2, Spokane^1,2, Stevens^1,2, Whatcom^1,2, Whitman^1,2, Yakima^1,2. Seasonality: Apr^1,2, May^1,2, Jun^1,2, Jul^1,2, Aug^1,2, Sep^1,2, Oct^1,2 (2022^1,2). Collections: iNaturalist

166b. Bombus (Pyrobombus) vancouverensis vancouverensis Cresson, 1879. County records: San Juan^1,2,68, Skagit^1,2. Seasonality: Mar^1,2, Apr^1,2,3, May^1,2,3, Aug^1,2 (2020^1,2). Collections: iNaturalist

167. § Bombus (Pyrobombus) vandykei (Frison, 1927). County records: Chelan^1,2,3, Clallam^3,124, Douglas^1,2, Grays Harbor^1,2, Jefferson^1,69,124, King^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Mason^1,2,3, Okanogan^1,2,3,59, Pierce^1,2,3, San Juan¹²⁴, Snohomish^1,2,3, Thurston^1,2,3, Whatcom^1,2, Whitman^1,2,3, Yakima^1,2,3,105. Seasonality: Mar^1,2, Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2 (2021^1,2). Collections: AMNH, BBSL, BOMBUS, CAS, EMEC, iNaturalist, INHS, JRYA, LACM, NMNH, PMNH, UCRC. [= Bombus flavifrons var. vandykei Frison, 1927]. Holotype. USA, Washington, Yakima County, Mt. Adams, Yakima Indian Forest Reservation; CAS #2437. [= Pyrobombus cascadensis Milliron, 1970]. Conservation status: Least Concern (Hatfield et al. 2015l); G4 – Apparently Secure globally, S3 – Vulnerable in Washington (NatureServe 2024). Floral records: FABACEAE: Lupinus^3,59; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹

168. Bombus (Pyrobombus) vosnesenskii Radoszkowski, 1862. County records: Benton^1,2,3, Chelan^1,2, Clallam^1,2,3,6,124, Clark^1,2,3,124, Cowlitz^1,2,3, Douglas^1,2, Garfield^1,2,3, Grays Harbor^1,2, Island^1,2,3,124, Jefferson^1,2,3,6,124, King^1,2,3,6, Kitsap^1,2,3, Kittitas^1,2, Klickitat^1,2, Lewis^1,2,4, Lincoln^1,2, Mason^1,2,3, Okanogan^1,2, Pacific^1,2,3,6, Pierce^1,2,3,6, San Juan^{1,2,3,5,6,136}, Skagit^1,2,3,6,10, Skamania^1,2,3, Snohomish^1,2,6, Stevens^1,2, Thurston^{1,2,3,6,130,133}, Wahkiakum^1,2, Walla Walla^1,2,3, Whatcom^1,2,6,33, Whitman^1,2, Yakima^1,2,3. Seasonality: Jan^1,2, Feb^1,2, Mar^1,2, Apr^1,2,5,33,133, May^1,2,5,33,133, Jun^1,2,3,5,133, Jul^{1,2,3,5,6,133}, Aug^1,2,6,33, Sep^1,2,6, Oct^1,2,3, Nov^1,2, Dec^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, BugGuide, CNC, CSCA, EMEC, FMNH, iNaturalist, INHS, LACM, NMNH, PCYU, PMNH, PWRC, SEMC, TAMU, UCRC, WSDA. Conservation status: Least Concern (Hatfield et al. 2015m); G5 – Secure globally, S5 – Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Brodiaea coronaria¹³³, Camassia quamash¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Cirsium arvense¹³³, Crepis capillaris¹³³, Erigeron speciosus¹³³, Eriophyllum lanatum¹³³, Grindelia integrifolia⁵, Hypochaeris radicata^5,133, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Senecio jacobaea¹³³, Solidago missouriensis¹³³, S. simplex¹³³, Taraxacum officinale¹³³; BRASSICACEAE: Lepidium campestre¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus^133,136; CARYOPHYLLACEAE: Cerastrium arvense¹³³; ERICACEAE: Arctostaphylos uva-ursi¹³³; FABACEAE: Lathyrus japonicus¹³⁶, Lupinus albicaulis¹³³, L. bicolor¹³³, L. lepidus¹³³, L. littoralis¹³⁶, Trifolium pratense¹³³, T. repens¹³³, Vicia americana¹³³, V. hirsuta¹³³, V. sativa^133,136; GROSSULARIACEAE: Ribes⁵; HYPERICACEAE: Hypericum perforatum¹³³; LAMIACEAE: Prunella vulgaris¹³³; OROBANCHACEAE: Castilleja hispida¹³³, C. levisecta¹³³, Parentucellia viscosa¹³³; PAPAVERACEAE: Eschscholzia californica⁵; PLANTAGINACEAE: Collinsia grandiflora¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; POLEMONIACEAE: Gilia capitata¹³³; PRIMULACEAE: Dodecatheon hendersonii¹³³; RANUNCULACEAE: Delphinium nuttallii¹³³; ROSACEAE: Potentilla gracilis¹³³, Rubus bifrons¹³⁶; SAPINACEAE: Acer macrophyllum⁵

169. § Bombus (Subterraneobombus) appositus Cresson, 1879. County records: Asotin^1,2,3, Chelan^1,2,3, Clallam^1,2,3,124, Clark^1,2,124, Columbia^1,2,3, Ferry^1,2, Franklin^1,2,3, Garfield^1,2,3, Grant³, King^1,2, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lincoln^1,2, Mason³, Okanogan^1,2,3,59, Pend Oreille^1,2,3, San Juan^1,2,3,5, Skagit³, Spokane^1,2,3, Stevens^1,2,3, Thurston^1,2,3, Walla Walla^1,2,3, Whatcom^1,2,3, Whitman^1,2,3,6,8, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3, Jun^1,2,3, Jul^1,2,3,5,6, Aug^1,2,3,6, Sep^1,2, Oct^1,2, Nov^2,3 (2022^1,2). Collections: BBSL, BOMBUS, BugGuide, CNC, CSCA, FMNH, iNaturalist, INHS, JRYA, LACM, NMNH, PMNH, TAMU, UCRC, WSDA, WSUC. Conservation status: Least Concern (Hatfield et al. 2015n); G3 – Vulnerable globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Balsamorhiza sagittata⁸, Cirsium³, C. arvense⁵; BORANGINACEAE: Myosotis laxa⁵⁹; FABACEAE: Lupinus³, Medicago sativa³, Vicia villosa⁸; HYDROPHYLLACEAE: Phacelia⁸; LAMIACEAE: Agastache urticifolia⁸; OROBANCHACEAE: Orthocarpus tenuifolius^3,59; PLANTAGINACEAE: Penstemon confertus^3,59, P. washingtonensis^3,59

170. § Bombus (Thoracobombus) fervidus (Fabricius, 1798) species complex. County records: Adams^1,2,3, Asotin^1,2,3, Benton^1,2,3,71, Chelan^1,2,3, Clallam^1,2,3, Clark^1,2, Columbia^1,2, Cowlitz^1,2,3, Douglas^1,2, Ferry^1,2, Franklin^1,2,3, Garfield^1,2,46, Grant^1,2,3, Grays Harbor^1,2,6,70, Island^1,2.3, Jefferson^1,2,3, King^1,2,3, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lewis^1,2,3, Lincoln^1,2, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3,6, Pend Oreille^1,2, Pierce^1,2,3,6, San Juan^1,2,3, Skagit^1,2,10.70, Skamania^1,2, Snohomish^1,2,3, Spokane^1,2,3, Stevens^1,2, Thurston^1,2,3,6,133, Wahkiakum^1,2, Walla Walla^1,2,3, Whatcom^1,2,33, Whitman^1,2,3,6,8, Yakima^1,2,3. Seasonality: Jan^1,2, Mar^1,2, Apr^1,2,3,133, May^1,2,3,133, Jun^1,2,3,133, Jul^1,2,3,6, Aug^1,2,3,6,33, Sep^1,2,3,6, Oct^1,2,3, Nov^1,2, Dec^1,2 (2022^1,2). Collections: AMNH, BBSL, BOMBUS, BugGuide, CNC, EMEC, FMNH, iNaturalist, INHS, LACM, NMNH, PMNH, OSUC, SEMC, TAMU, UCDC, UCRC, WSDA, WSUC. Conservation status: Vulnerable (Hatfield et al. 2015p); G3 – Vulnerable globally, S4 – Apparently Secure in Washington (NatureServe 2024). Floral records: ASPARAGACEAE: Camassia quamash¹³³, Triteleia grandiflora⁸; ASTERACEAE: Anaphalis margaritacea⁸, Balsamorhiza deltoidea¹³³, B. sagittata⁸, Cirsium vulgare⁸, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Rudbeckia occidentalis⁸, Taraxacum officinale¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus¹³³; CONVOLVULACEAE: Ipomoea³; DIPSACACEAE: Dipsacus fullonum⁸,; FABACEAE: Astragalus sinuatus³, Lathyrus odoratus³, Lupinus albicaulis¹³³, L. polyphyllus⁸, Medicago sativa⁸, Trifolium pratense¹³³, T. repens^3,59,133, Vicia americana¹³³, V. sativa¹³³, V. villosa⁸; GERANIACEAE: Geranium viscosissimum⁸; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; HYPERICACEAE: Hypericum perforatum¹³³; IRIDACEAE: Sisyrinchium⁸; LAMIACEAE: Agastache urticifolia⁸, Prunella vulgaris¹³³; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium⁸; OROBRANCHACEAE: Castilleja hispida¹³³, C. levisecta¹³³, C. miniata⁵⁹, Parentucellia viscosa¹³³; PLANTAGINACEAE: Collinsia grandiflora¹³³, Penstemon washingtonensis⁵⁹; RANUNCULACEAE: Delphinium nuttallii¹³³; ROSACEAE: Malus domestica⁸, Rosa⁸. Comments: Bombus fervidus and B. californicus are morphologically identical, but molecular analysis by Koch et al. (2018) supports the existence of two distinct lineages. However, based on the original species description, it is unclear which name is attributed to which species, or if these names represent two variations of the same species (Koch et al. 2018). Records of both species are presented here as a single species complex.

Eucerinae: Emphorini

Genus Diadasia Patton

171. Diadasia (Coquillettapis) diminuta (Cresson, 1878). County records: Asotin³⁶, Benton^1,2,3, Chelan^1,2,3, Walla Walla^1,2, Whatcom³, Whitman³⁶, Yakima⁷. Seasonality: May^1,2,3, Jun^1,2,3,7, Jul^1,2,7, Aug³ (2022^1,2). Collections: BBSL, iNaturalist, JRYA, UCRC, WSUC

172. † Diadasia (Coquillettapis) lutzi Cockerell, 1924. County records: Benton⁷, Yakima⁷. Seasonality: May⁷ (2015⁷). Collections: WSUC

173. Diadasia (Coquillettapis) nigrifrons (Cresson, 1878). County records: Chelan¹, Kittitas^1,2,3, Whitman^8,36, Yakima³⁶. Seasonality: Jul^1,2,3 (2023¹). Collections: SEMC, WSUC. Floral records: MALVACEAE: Sidalcea oregana⁸

174. ‡ Diadasia (Coquillettapis) nitidifrons Cockerell, 1905. County records: Chelan³, Yakima³⁶. Seasonality: Jun¹ (1919¹). Collections: UCRC

175. ‡ Diadasia (Dasiapis) ochracea (Cockerell, 1903). County records: Whitman³⁶, Yakima^7,36,121. Seasonality: Jun^7,121 (1903^7,121). Collections: WSUC. Comments: Adlakha (1969) synonymizes D. ochracea with D. olivacea; however, Snelling (1994) determined these were separate species and notes Washington records as D. ochracea.

176. Diadasia (Diadasia) enavata (Cresson, 1872). County records: Asotin^1,2, Benton^1,2,3,7, Klickitat^2,3, Walla Walla^{1,2,3,7,36,71}, Whitman^1,2,3,7,8,36, Yakima⁷. Seasonality: Jun^1,2,7, Jul^1,2,3,7, Aug^1,2,3,7, Sep^1,2 (2012^1,2). Collections: BBSL, BugGuide, INHS, TAMU, WSUC. Floral records: ASTERACEAE: Helianthus^3,7, H. annuus⁸

Eucerini

Genus Epimelissodes Ashmead

177. Epimelissodes (Epimelissodes) obliquus (Say, 1837). County records: Yakima². Seasonality: Jul² (2015²). Collections: BugGuide, iNaturalist

177a. Epimelissodes (Epimelissodes) obliquus expurgatus Cockerell, 1925. County records: Benton^1,2,3, Grant^1,2, Walla Walla^1,2,3, Whitman⁷², Yakima⁷². Seasonality: Jul^1,2, Aug^1,2,3 (2020^1,2). Collections: BBSL, iNaturalist

Genus Eucera Scopoli

178. Eucera (Synhalonia) actuosa (Cresson, 1878). County records: Benton^1,2,3, Chelan^1,2,3, Garfield^1,2,3,46, Spokane^1,2, Whitman^8,109. Seasonality: Mar^1,2, Apr^1,2,3, May^1,2,3,109, Jun^1,2,3,46 (2015^1,2). Collections: BBSL, SEMC, WSUC. Floral records: ASTERACEAE: Balsamorhiza careyana³, B. sagittata⁸; FABACEAE: Lupinus⁸, Onobrychis viciifolia³, Vicia villosa⁸; ROSACEAE: Malus domestica⁸, Prunus virginiana⁸

179. Eucera (Synhalonia) amsinckiae (Timberlake, 1969). County records: Benton^1,2,3, Walla Walla^1,2,3, Whitman¹⁰⁹. Seasonality: Apr^1,2,3, May^1,2,3 (2015^1,2). Collections: BBSL

180. †‡ Eucera (Synhalonia) angustifrons (Timberlake, 1969). County records: Spokane². Seasonality: Jun² (1957²). Collections: SEMC

181. Eucera (Synhalonia) delphinii (Timberlake, 1969). County records: Asotin^1,2,3,109, Garfield⁴⁶, Spokane^1,2, Stevens^1,2, Whitman^1,2,3,109. Seasonality: Apr^1,2, May^1,2,109, Jul^1,2,3,109 (2015^1,2). Collections: BBSL, SEMC

182. § Eucera (Synhalonia) douglasiana (Cockerell, 1906). County records: Benton^1,2, Grant^109,112,121. Seasonality: Apr^1,2, Jul^109,121 (2015^1,2). Collections: BBSL. [= Tetralonia douglasiana Cockerell, 1906]. Conservation status: Vulnerable (Shepherd 2005b; National Research Council 2007). Comments: Cockerell (1906b) and Timberlake (1969) note a record at Steamboat Rock, Grand Coulee in Douglas County; however, Steamboat Rock, Grand Coulee is located in Grant County.

183. Eucera (Synhalonia) edwardsii (Cresson, 1878). County records: Benton^1,2,3, Chelan¹³⁶, Franklin^1,2,118, Garfield^1,2,3,46, Grant⁶, Klickitat^1,2, Spokane^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3,6,8, Yakima^1,2,3,6. Seasonality: Apr^1,2,3, May^1,2,3,118, Jun^1,2,3,6, Jul^1,2 (2022⁶). Collections: BBSL, NMNH, SEMC, WSDA, WSUC. Floral records: DIPSACACEAE: Dipsacus fullonum⁸; FABACEAE: Astragalus bungeanus³, A. columbianus³, Lupinus polyphyllus⁸, Vicia villosa⁸

184. Eucera (Synhalonia) frater (Cresson, 1878). County records: Benton^1,2, Chelan^1,2,3, Garfield^1,2,46, Jefferson^1,2, Klickitat^1,2, San Juan^1,2,124,136, Stevens^1,2,109, Thurston^1,2,118, Walla Walla^1,2,3, Whitman^1,2,3,6,8,61. Seasonality: Mar¹, Apr^1,2,109,118, May^1,2,3,118, Jun^{1,2,3,6,46,118}, Jul^1,2,118, Aug^1,2 (2017¹³⁶). Collections: BBSL, BugGuide, NMNH, PWRC, WSDA, WSUC. [= Synhalonia edwardsii latior Cockerell, 1897]. Floral records: ASPARAGACEAE: Triteleia grandiflora⁸; ASTERACEAE: Balsamorhiza sagittata⁸, Hypochaeris radicata¹³⁶; FABACEAE: Astragalus sinuatus³, Lathyrus japonicus¹³⁶, Lupinus^3,118, Trifolium repens⁸, Vicia sativa¹³⁶; OLEACEAE: Syringa⁸; PLANTAGINACEAE: Penstemon attenuatus⁸; ROSACEAE: Malus domestica⁸

184a. § Eucera (Synhalonia) frater lata (Provancher, 1888). County records: Asotin^1,2,3,109, Chelan^1,2,3, Garfield^1,2,3, Island¹⁰⁹, Jefferson^1,2, King¹⁰⁹, Pierce^1,2,3, San Juan^{1,2,3,5,22,124}, Whitman^1,2,109. Seasonality: Apr^1,2,3,5, May^1,2,3,5,109, Jun^1,2,3,5,109, Jul^1,2,3,109, Aug¹⁰⁹ (2015^1,2,22). Collections: BBSL, PWRC, SEMC. Conservation status: Vulnerable (Shepherd 2005c; National Research Council 2007). Floral records: ASPARAGACEAE: Camassia quamash⁵; ASTERACEAE: Taraxacum officinale⁵; BERBERIDACEAE: Berberis aquifolium⁵; FABACEAE: Astragalus bungeanus³, A. cicer³; HYDROPHYLLACEAE: Hydrophyllum¹⁰⁹

185. Eucera (Synhalonia) fulvitarsis (Cresson, 1878). County records: Benton^1,2,3,109, Chelan^1,2,3,109, Douglas^1,2, Garfield⁴⁶, Walla Walla^1,2, Yakima^{1,2,3,109,121}. Seasonality: Mar^1,2, Apr^1,2,3,121, May^1,2,3 (2015^1,2). Collections: BBSL, SEMC. [= Synhalonia yakimensis Cockerell, 1906]. Holotype. USA, Washington, Yakima County, Yakima. [= Tetralonia yakimensis Cockerell, 1906]. Floral records: FABACEAE: Astragalus columbianus³

186. Eucera (Synhalonia) hurdi (Timberlake, 1969). County records: Asotin², Spokane^1,2, Whitman^3,109. Seasonality: Apr^1,2,3,109, May^1,2 (2015^1,2). Collections: BBSL, SEMC

187. † Eucera (Synhalonia) speciosa (Cresson, 1878). County records: Benton^1,2,3. Seasonality: May^1,2,3, Jun^1,2 (2015^1,2). Collections: BBSL

Genus Melissodes Latreille

188. Melissodes (Callimelissodes) glenwoodensis Cockerell, 1905. County records: Grant⁴⁹

189. Melissodes (Callimelissodes) lupinus Cresson, 1878. County records: Benton^1,2,7,71, Klickitat^1,2, Walla Walla^1,2,7,71, Whitman^1,2,7,8,49, Yakima⁷. Seasonality: Jun^1,2,7, Jul^1,2,7, Aug^1,2, Sep^1,2 (2015^1,2). Collections: BBSL, WSUC. Floral records: ASTERACEAE: Helianthus annuus⁸

190. ‡ Melissodes (Callimelissodes) metenua Cockerell, 1924. County records: Kittitas^1,2, Whitman^7,8, Yakima⁴⁹. Seasonality: Jul^1,2,7, Aug⁷ (1962⁷). Collections: TAMU, WSUC. Floral records: ASTERACEAE: Pyrrocoma liatriformis⁸

191. ‡ Melissodes (Callimelissodes) plumosus LaBerge, 1961. County records: Yakima⁴⁹. Seasonality: Jul⁴⁹, Aug⁴⁹ (1941⁴⁹)

192. ‡ Melissodes (Callimelissodes) stearnsi Cockerell, 1905. County records: Kittitas^1,2,49, Okanogan^1,2,3, Seasonality: Jul^1,2,3 (1949^1,2). Collections: BBSL, SEMC

193. Melissodes (Eumelissodes) agilis Cresson, 1878. County records: Adams^7,49, Asotin^1,2,49, Benton^1,2,3,7,71, Chelan^7,49, Douglas^1,2, Garfield⁷, Grant^1,2, Klickitat⁴⁹, Spokane^1,2, Walla Walla^{1,2,3,7,49,71}, Whitman^1,2,7,8,49, Yakima^7,49. Seasonality: Jun^1,2,3,7, Jul^1,2,7, Aug^1,2,3,7, Sep^1,2,7, Oct^1,2,7 (2015⁷). Collections: BBSL, SEMC, TAMU, WSUC. Floral records: ASTERACEAE: Helianthus annuus⁸; GERANIACEAE: Geranium⁸

194. Melissodes (Eumelissodes) bimatris LaBerge, 1961. County records: Benton⁷, Franklin⁴⁹, Grant⁴⁹, Okanogan⁴⁹, Walla Walla⁴⁹, Whitman⁷, Yakima⁴⁹. Seasonality: Sep⁷ (1993⁷). Collections: WSUC

195. † Melissodes (Eumelissodes) brevipyga LaBerge, 1961. County records: Benton⁷, Yakima⁷. Seasonality: Jul⁷ (2015⁷). Collections: WSUC

196. Melissodes (Eumelissodes) grindeliae Cockerell, 1898. County records: Yakima⁴⁹

197. Melissodes (Eumelissodes) lutulentus LaBerge, 1961. County records: Adams^7,49, Benton⁷, Walla Walla⁷. Seasonality: Jun⁷, Aug⁷ (2015⁷). Collections: WSUC

198. Melissodes (Eumelissodes) menuachus Cresson, 1868. County records: Benton^1,2, Grant⁴⁹, Okanogan^2,3, Walla Walla^1,2,3,71. Seasonality: Aug^1,2, Sep^1,2,3 (2015^1,2). Collections: BBSL, SEMC

199. Melissodes (Eumelissodes) microstictus Cockerell, 1905. County records: Benton⁷, Chelan⁷, Island^2,7,49, King^1,2,49, Kitsap^{7,23, 134}, Kittitas^1,2, Klickitat^1,2, Okanogan^1,2,59, Pend Oreille⁴⁹, Pierce^1,2,49, San Juan^1,2,7,49,124, Spokane^1,2,49, Thurston^1,2,49, Walla Walla^1,2,7,49, Whatcom^7,49, Whitman^2,49, Yakima⁴⁹. Seasonality: Apr^1,2, Jun^1,2,7, Jul^1,2,7,134, Aug^1,2,7,134, Sep^1,2 (2015^1,2). Collections: BBSL, FMNH, iNaturalist, INHS PWRC, SEMC, TAMU, WSUC. Floral records: ASTERACEAE: Anaphalis margaritacea⁵⁹, Erigeron speciosus⁵⁹, Hypochaeris radicata¹³⁴

200. Melissodes (Eumelissodes) pallidisignatus Cockerell, 1905. County records: Benton^1,2,7, Island^2,3,49, Jefferson^1,2, Kittitas², Klickitat², Okanogan^1,2,59, Pend Oreille^2,49, Stevens⁴⁹, Walla Walla^1,2,7,8,71, Whitman², Yakima². Seasonality: Jun^1,2, Jul^1,2,7, Aug^1,2,3, Sep^1,2 (2015^1,2). Collections: BBSL, INHS, SEMC, UCRC, WSUC. Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Erigeron speciosus⁵⁹, Senecio triangularis⁵⁹; BRASSICACEAE: Sisymbrium altissimum⁵⁹

201. Melissodes (Eumelissodes) paululus LaBerge, 1961. County records: Benton⁷, Walla Walla^1,2,71, Yakima⁴⁹. Seasonality: Jun^1,2, Jul^1,2, Aug^1,2, Sep^1,2 (1998^1,2). Collections: BBSL, WSUC

202. Melissodes (Eumelissodes) robustior Cockerell, 1915. County records: Adams⁷, Asotin⁴⁹, Benton^1,2,7, Spokane⁷, Walla Walla^1,2,3,7,49, Whitman^1,2,3,7,8,49, Yakima^7,49. Seasonality: Jun^1,2,3,7, Jul^2,3,7, Aug⁷ (1995^1,3). Collections: BBSL, INHS, SEMC, WSUC. Floral records: ASTERACEAE: Helianthus annuus⁸

203. Melissodes (Eumelissodes) saponellus Cockerell, 1908. County records: Benton^1,2,7, Grant⁴⁹, Yakima⁷. Seasonality: May^1,2,7, Jun^1,2,7,49, Jul⁷ (2015^1,2,7). Collections: BBSL, WSUC. Holotype. USA, Washington, Grant County, Grand Coulee, Soap Lake; 29 June 1902

204. Melissodes (Eumelissodes) semilupinus Cockerell, 1905. County records: Benton^1,7, Chelan¹, Walla Walla^7,49, Whitman⁷, Yakima^2,7. Seasonality: Jul⁷, Aug^1,7, Sep^1,2,7, Oct⁷ (1995¹). Collections: INHS, WSUC

205. Melissodes (Eumelissodes) subagilis Cockerell, 1905. County records: Adams⁷, Benton⁷, Grant^7,49. Seasonality: Jul⁷, Aug⁷, Sep⁷ (2015⁷). Collections: WSUC

206. ‡ Melissodes (Eumelissodes) verbesinarum Cockerell, 1905. County records: Adams⁴⁹, Yakima⁷. Seasonality: Aug⁷ (1957⁷). Collections: WSUC

207. Melissodes (Eumelissodes) vernalis LaBerge, 1961. County records: Adams⁴⁹, Benton⁷. Seasonality: Jun⁷ (2014⁷). Collections: WSUC

208. Melissodes (Heliomelissodes) rivalis Cresson, 1872. County records: Adams^7,108, Asotin¹⁰⁸, Benton^1,2,3,7,71, Columbia⁷, Garfield¹⁰⁸, Grant⁷, King^1,2,3, Kittitas^1,2,3, Klickitat^1,2,7, Lewis^2,3,108, Lincoln¹⁰⁸, San Juan^1,2,3,124, Walla Walla^1,2,7,71, Whitman^7,8,108, Yakima^7,108. Seasonality: Jun^1,2,3,7, Jul^1,2,3,7, Aug^1,2,7, Sep^1,2, Oct^1,2 (2012^1,2). Collections: BBSL, PWRC, SEMC, WSUC. Floral records: ASTERACEAE: Cirsium vulgare⁸

209. Melissodes (Melissodes) communis Cresson, 1878. County records: Walla Walla^1,2,3. Seasonality: Jul^1,2,3 (1998^1,2,3). Collections: BBSL

209a. Melissodes (Melissodes) communis alopex Cockerell, 1928. County records: Asotin^2,3,72, Benton⁷, Yakima^1,2,7,72. Seasonality: Jun^2,3,7, Jul^1,2,3,7 (2015⁷). Collections: SEMC, WSUC

210. Melissodes (Tachymelissodes) dagosus Cockerell, 1909. County records: Adams^7,108, Benton⁷, Grant^7,108, Lincoln⁷, Yakima^7,108. Seasonality: Jun⁷, Jul⁷ (1973⁷). Collections: WSUC

Nomadinae: Ammobatini

Genus Oreopasites Cockerell

211. Oreopasites (Oreopasites) vanduzeei Cockerell, 1925. County records: Benton^1,2,3,9. Seasonality: May^1,2,3, Jun⁹ (1990^1,2,3). Collections: AMNH

Epeolini

Genus Epeolus Latreille

212. † Epeolus americanus (Cresson, 1878). County records: Benton^1,2, Walla Walla^1,2. Seasonality: Apr^1,2, May^1,2 (2022^1,2). Collections: BBSL, iNaturalist

213. Epeolus compactus Cresson, 1878. County records: King^1,2, Klickitat^1,2, Pierce^1,2,4,73,74, Thurston^1,2. Seasonality: Jun^1,2,74, Jul^1,2,4,73 (2021^1,2). Collections: BBSL, iNaturalist, PCYU. Host records: Colletes kincaidii Cockerell⁷³

214. Epeolus emiliae Onuferko and Sheffield, 2022. County records: Benton^1,64. Seasonality: Sep¹, Oct^1,64 (2023¹). Collections: iNaturalist. Comments: iNaturalist record #98573666

215. Epeolus minimus (Robertson, 1902). County records: Benton^1,2, Ferry^1,2, Spokane^1,2, Thurston³. Seasonality: May^1,2, Jul^1,2, Aug^1,2 (2015^1,2). Collections: AMNH, BBSL, SEMC

216. † Epeolus novomexicanus Cockerell, 1912. County records: Benton^1,2. Seasonality: Sep^1,2 (2021^1,2). Collections: iNaturalist

217. Epeolus olympiellus Cockerell, 1904. County records: Benton^1,2, Douglas^1,2, Garfield^1,2,4,73,74, San Juan²², Thurston^{1,2,3,52,73,74,118}, Whitman^1,2,73,74. Seasonality: May^1,2,4,74, Jun^1,2,74, Jul^{1,2,3,52,73,74,118}, Aug^1,2,73,74 (2021^1,2). Collections: AMNH, iNaturalist, NMNH, PCYU. Holotype. USA, Washington, Thurston County, Olympia; 2 July 1896; T Kincaid; USNM 534051. [= Epeolus humillimus Cockerell, 1918]. Holotype. USA, Washington, Whitman County, Pullman; 2 August 1908; WM Mann; Type No. 100017, USNM ENT 00534047

Genus Triepeolus Robertson

218. Triepeolus argus Rightmyer, 2008. County records: Benton^3,75, Yakima^3,75. Seasonality: Sep^3,75, Oct³ (1993^3,75). Collections: Miliczky. Host records: Melissodes pallidisignatus Cockerell⁷⁵. Floral records: ASTERACEAE: Ericameria nauseosa var. nauseosa^3,75

219. Triepeolus argyreus (Cockerell, 1907). County records: Benton³, Klickitat³, Walla Walla³, Yakima^3,75. Seasonality: Aug^3,75, Sep³ (1992³). Collections: Miliczky. Holotype. USA, Washington, Yakima County, North Yakima; 4 August 1903; USNM No. 100019. Host records: Melissodes pallidisignatus Cockerell^3,75. Floral records: ASTERACEAE: Centromadia pungens ssp. pungens³, Dieteria canescens³, Ericameria nauseosa var. nauseosa³

220. † Triepeolus concavus (Cresson, 1878). County records: Adams³, Franklin¹, Yakima³. Seasonality: Jul³, Aug³ (2023¹). Collections: NMNH, iNaturalist. Host records: Epimelissodes obliquus (Say)⁷⁵

221. † Triepeolus grindeliae Cockerell, 1907. County records: Benton^1,2,3. Seasonality: May^1,2, Jun^1,2,3, Sep^1,2 (1995^1,2,3). Collections: BBSL. Floral records: ASTERACEAE: Rhaponticum repens³

222. † Triepeolus helianthi (Robertson, 1897). County records: Klickitat^2,3, Whitman^2,3. Seasonality: Aug^2,3, Sep^2,3 (1982^2,3). Collections: INHS. Host records: Nomia melanderi Cockerell⁷⁵, Melissodes agilis Cresson⁷⁵

223. Triepeolus paenepectoralis Viereck, 1905. County records: Island³, Jefferson^1,2, Kitsap^2,3,75, Klickitat^1,2, Okanogan⁵⁹, Whitman^1,2,3,51. Seasonality: Jul^1,2, Aug^1,2,3,51, Sep^1,2,3,51 (2022^1,2). Collections: BBSL, iNaturalist, INHS. Host records: Melissodes microstictus Cockerell⁷⁵

224. Triepeolus texanus (Cresson, 1878). County records: Walla Walla^1,2, Whitman³, Yakima^1,2,75. Seasonality: Jun^1,2, Jul³, Aug^1,2,75 (2012^1,2). Collection: BBSL, NMNH. [= Triepeolus eldredi Cockerell, 1907]. Holotype. USA, Washington, Yakima County, North Yakima; 7 August 1903; USNM No. 100029. Host records: Melissodes druriellus (Kirby)⁷⁵, Nomia melanderi Cockerell⁷⁵

225. † Triepeolus timberlakei Cockerell, 1929. County records: Whitman^1,2,3. Seasonality: Sep^1,2,3 (1982^1,2,3). Collections: BBSL

Melectini

Genus Brachymelecta Linsley

226. † Brachymelecta californica (Cresson, 1878). County records: Benton⁷, Jefferson^1,2, Whitman⁷, Yakima⁷. Seasonality: Jun⁷, Aug^1,2, Sep⁷ (2022^1,2). Collections: iNaturalist, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024)

Genus Melecta Latreille

227. Melecta (Melecta) pacifica Cresson, 1878. County records: Benton^1,2, Okanogan^1,2,3,59, Spokane^1,2, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2, Jun^1,2,3 (2015^1,2). Collections: BBSL, SEMC

227a. Melecta (Melecta) pacifica fulvida Cresson, 1879. County records: Whitman³⁵

228. Melecta (Melecta) separata Cresson, 1879. County records: Chelan¹³⁶, Pierce^1,2, Spokane^1,2, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3 (2020^1,2). Collections: BBSL, iNaturalist. Floral records: FABACEAE: Astragalus speirocarpus³

228a. Melecta (Melecta) separata callura (Cockerell, 1926). County records: Walla Walla³⁵. Comments: Linsley (1939) lists the Washington record as Whitman County (Walla Walla). Walla Walla is located in Walla Walla County.

228b. † Melecta (Melecta) separata separata Cresson, 1879. County records: Benton^1,2, Chelan^1,2, Walla Walla^1,2,3. Seasonality: Mar^1,2, Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2 (2022^1,2). Collections: BBSL, iNaturalist

229. † Melecta (Melecta) thoracica Cresson, 1875. County records: Douglas^1,2, Spokane^1,2, Whitman³. Seasonality: Apr^1,2,3, May^1,2,3 (2015^1,2). Collections: BBSL

Genus Zacosmia Ashmead

230. ‡ Zacosmia maculata maculata (Cresson, 1879). County records: Walla Walla^3,35. Seasonality: Jun³ (1936³). Collections: BBSL. Comments: Linsley (1939) lists the Washington record as Whitman County (Walla Walla). Walla Walla is located in Walla Walla County.

Nomadini

Genus Nomada Scopoli

231. Nomada aldrichi Cockerell, 1910. County records: Spokane⁷⁶. Seasonality: May⁷⁶. [= Nomada vicinalis aldrichi Cockerell, 1910]

232. ‡ Nomada articulata Smith, 1854. County records: Kitsap^1,2,3, Whitman⁷⁶. Seasonality: May^1,2,3,76 (1965^1,2,3). Collections: BBSL, BugGuide

233. ‡ Nomada bella Cresson, 1863. County records: King¹²⁰, Thurston¹²⁰. Seasonality: Jun¹²⁰ (1897¹²⁰)

234. Nomada civilis Cresson, 1878. County records: Whitman⁷⁶. Seasonality: May⁷⁶. Comments: Discover Life has synonymized N. civilis with N. opposita without reference or explanation. We are not aware of any published work that that synonymizes these species and retain them as separate taxa in this checklist.

234a. Nomada civilis spokanensis Cockerell, 1910. County records: Spokane^1,2,3,76. Seasonality: May^3,76. Collections: NMNH. Holotype. USA, Washington, Spokane County, Spokane; 30 May; WM Mann; Type No. 29476, USNM ENT 00533989. Comments: Discover Life has synonymized N. civilis spokanensis with N. opposita without reference or explanation. We are not aware of any published work that that synonymizes these species and retain them as separate taxa in this checklist.

235. Nomada citrina Cresson, 1878. [= Xanthidium citrinum Cresson, 1878]. Comments: Viereck et al. (1905) notes N. citrina occurs in Washington, but do not provide a locality.

236. †‡ Nomada collinsiana Cockerell, 1905. County records: Walla Walla^1,2,3. Seasonality: May^1,2,3, Jun^1,2 (1939^1,2). Collections: BBSL

237. Nomada coquilletti Cockerell, 1903. County records: Whitman⁷⁶. Seasonality: Mar⁷⁶, Apr⁷⁶

238. ‡ Nomada cressonii trevoriana Viereck, 1905. County records: Thurston^1,2,76,118. Seasonality: Apr^1,2,118 (1894^1,2,118). Collections: NMNH. Holotype. USA, Washington, Thurston County, Olympia; 22 April 1894

239. † Nomada crotchii Cresson, 1878. County records: Benton^1,2, Walla Walla^1,2,3. Seasonality: Mar^1,2, May^1,2,3 (2022^1,2). Collections: BBSL, iNaturalist

240. Nomada cuneata (Robertson, 1903). County records: Whitman⁷⁶. Seasonality: May⁷⁶

241. Nomada edwardsii Cresson, 1878. County records: Benton^1,2, Kittitas^2,3, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,2,3,76. Seasonality: Mar^1,2, Apr^1,2,3, May^1,2,3, Jun^1,2,76, Jul^1,2,3 (2015^1,2). Collections: BBSL, INHS. [= Holonomada edwardsii Cresson, 1878]

241a. Nomada edwardsii vinnula Cresson, 1879. County records: Spokane⁷⁶, Whitman⁷⁶. Seasonality: May⁷⁶

242. ‡ Nomada erythrochroa Cockerell, 1903. County records: Franklin^{1,2,3,50,76,118}, Yakima^50,76. Seasonality: May^1,2,3,118, Jun^50,76 (1903⁵⁰). Collections: NMNH. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; Type No. 13185, USNM ENT 00533921

243. ‡ Nomada flammigera Cockerell, 1906. County records: Yakima^2,50,76. Seasonality: May^2,50, Jul⁷⁶ (1906⁷⁶). Collections: LACM. Holotype. USA, Washington, Yakima County, North Yakima; 15 May 1903; E Jenne.

244. Nomada grayi eastonensis Cockerell, 1903. County records: Kittitas^{1,2,3,76,118,120}. Collections: NMNH. Holotype. USA, Washington, Kittitas County, Easton; Type No. 13163, USNM ENT 00533917. [= Gnathias grayi eastonensis Cockerell, 1903]

245. Nomada hesperia hesperia Cockerell, 1903. County records: Kittitas³, Walla Walla^1,2,3, Whitman^2,3,76,77. Seasonality: Apr^3,77, May^1,2,3,76,77, Jun⁷⁷ (1989³). Collections: BBSL, INHS. Floral records: ASTERACEAE: Balsamorhiza³

246. Nomada itamera Cockerell, 1910. County records: Whitman^2,76. Seasonality: May⁷⁶. Collections: AMNH. Holotype. USA, Washington, Whitman County, Pullman; WM Mann; AMNH_IZC 00323820

247. ‡ Nomada jennei Cockerell, 1906. County records: Yakima^1,2,3,121. Seasonality: Sep^1,2,3,121 (1903^1,2,3,121). Collections: NMNH. Holotype. USA, Washington, Yakima County, North Yakima; 26 September 1903; E Jenne; Type No. 29484; USNM ENT 00533939

248. Nomada kincaidiana Cockerell, 1903. Holotype. USA: Washington State

249. Nomada lehighensis Cockerell, 1903. County records: Asotin⁶⁵. Seasonality: May⁶⁵ (2007⁶⁵). Collection: PCYU

250. ‡ Nomada malonella Cockerell, 1910. County records: Whitman^1,2,76. Seasonality: May^2,76 (1909^2,76). Collections: LACM, UCMC. Holotype. USA, Washington, Whitman County, Wawawai; 1 May 1909

251. ‡ Nomada malonina Cockerell, 1910. County records: Whitman^1,2,3,76. Seasonality: May^1,2,3,76 (1909^1,2,3,76). Collections: NMNH. Holotype. USA, Washington, Whitman County, Wawawai; 15 May 1909; WM Mann; Type No 29487, USNM ENT 00533947

252. Nomada mutans Cockerell, 1910. County records: Jefferson^1,2, Pacific¹¹⁰, Whitman^{1,2,3,76,110,111}, Yakima¹¹¹. Seasonality: Jun^1,2, Jul¹¹⁰, Aug^{1,2,3,76,110,111} (2015^1,2). Collections: BBSL, NMNH, UCMC. Holotype. USA, Washington, Whitman County, Pullman; 9 August 1908; WM Mann; USNM 13192. Paratype. USA, Washington, Whitman County, Pullman; 9 August 1908; WM Mann

253. ‡ Nomada orcusella Cockerell, 1910. County records: San Juan^2,76. Seasonality: Jul^2,76 (1909^2,76). Collections: LACM

254. ‡ Nomada packardiella Cockerell, 1906. County records: Ferry^1,2, Whitman⁷⁶. Seasonality: May⁷⁶, Aug^1,2 (1931^1,2). Collections: SEMC

255. Nomada pascoensis Cockerell, 1903. County records: Benton^2,3, Franklin^1,2,3,120, Klickitat^1,2, Walla Walla^1,2,3. Seasonality: Apr^2,3, May^1,2,3,120, Aug^1,2 (2011^1,2). Collections: BBSL, NMNH, SEMC

256. ‡ Nomada perbella (Viereck, 1905). County records: Grays Harbor^76,118, King⁷⁶, Thurston^76,118, Whitman⁷⁶. Seasonality: May^76,118, Jun¹¹⁸ (1904¹¹⁸). [= Gnathias perbella Viereck, 1905]

257. ‡ Nomada perplexans Cockerell, 1910. County records: Whitman^1,2,3,76. Seasonality: Jun^1,2,3,76 (1908^1,2,3,76). Collections: NMNH. Holotype. USA, Washington, Whitman County, Pullman; 7 June 1908; WM Mann; Type No. 29493, USNM ENT 00533967

258. Nomada pulsatillae Cockerell, 1906. County records: Spokane⁷⁶, Whitman⁷⁶. Seasonality: May⁷⁶

259. Nomada rivalis Cresson, 1878. [= Xanthidium rivale Cresson, 1878]. Comments: Viereck et al. (1905) note N. rivalis occurs in Washington, but do not provide a locality.

260. † Nomada scita Cresson, 1878. County records: Adams^1,2,3, Benton^1,2,3, Kittitas^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2 (2015^1,2). Collections: BBSL, SEMC

261. ‡ Nomada semisuavis Cockerell, 1910. County records: Whitman^1,2,76. Seasonality: Jul^1,2,76 (1908^1,2,76). Collections: LACM, UCMC. Holotype. USA, Washington, Whitman County, Wawawai; 4 July 1908; WM Mann

262. † Nomada suavis Cresson, 1878. County records: Clallam^1,2,3, Walla Walla^1,2,3, Whitman³. Seasonality: Jun^1,2,3, Jul^1,2,3 (2000^1,2,3). Collections: AMNH, BBSL. Host record: Nomia melanderi Cockerell⁷⁸

263. † Nomada texana Cresson, 1872. County records: Walla Walla^1,2, Whitman^1,2. Seasonality: Apr^1,2, Jul^1,2 (2011^1,2). Collections: BBSL, TTU. [= Nomada heiligbrodtii Cresson, 1878]

264. Nomada ultima Cockerell, 1903. County records: Spokane⁷⁶. Seasonality: May⁷⁶. [= Nomada modocorum Cockerell, 1903]

265. Nomada washingtoni Cockerell, 1903. Collections: NMNH. Holotype. USA, Washington State. [= Gnathias washingtoni Cockerell, 1903].

Xylocopinae: Ceratinini

Genus Ceratina Latreille

266. Ceratina (Zadontomerus) acantha Provancher, 1895. County records: Chelan^1,2,3, Clallam^1,2,3, Cowlitz^1,2,3, Jefferson^1,2, King^1,2,3,58,125, Kitsap^1,2,3, Klickitat^1,2, Mason³, Pierce^1,2,3, San Juan^5,6, Spokane^1,2, Thurston^6,125,133, Walla Walla^1,2,3,71, Whitman^1,2,3,6,8. Seasonality: Apr^1,2,5, May^1,2,3,5,58, Jun^1,2,3,133, Jul^1,2,3,5,6, Aug^1,2,3,6, Sep^1,2,6 (2020¹³³). Collections: AMNH, BBSL, JRYA, SEMC, TAMU, WSDA, WSUC. Floral records: APIACEAE: Lomatium⁸; ASPARAGACEAE: Camassia quamash⁵; ASTERACEAE: Cirsium vulgare⁸, Eriophyllum lanatum^8,133, Helianthus annuus⁸, Hypochaeris radicata⁵, Taraxacum officinale⁵; GERANIACEAE: Geranium viscosissiumum⁸; HYPERICACEAE: Hypericum perforatum¹³³; MALVACEAE: Iliamna longisepala³; PLANTAGINACEAE: Penstemon triphyllus⁸; ROSACEAE: Rosa⁸

267. †‡ Ceratina (Zadontomerus) micheneri Daly, 1973. County records: Whatcom⁷. Seasonality: Jun⁷ (1945⁷). Collections: WSUC

268. Ceratina (Zadontomerus) nanula Cockerell, 1897. County records: Jefferson^1,2, Klickitat^1,2, San Juan^{1,2,5,124,136}, Spokane^1,2, Thurston¹³³, Whitman^1,2,3,6,61. Seasonality: Apr^1,2,61, May^1,2,6,133, Jun^1,2,6,133, Jul^1,2,5,6,133, Aug^1,2,6, Sep^1,2, Oct^1,2 (2019¹³³). Collections: BBSL, PWRC, WSDA. Floral records: ASPARAGACEAE: Brodiaea coronaria^133,136; ASTERACEAE: Cirsium arvense¹³⁶, Crepis capillaris^5,133,136, Eriophyllum lanatum¹³³, Grindelia integrifolia⁵, Hypochaeris radicata^5,136, Taraxacum officinale¹³⁶; CARYOPHYLLACEAE: Cerastium arvense¹³³; CONVOLVULACEAE: Calystegia soldanella¹³⁶; ONAGRACEAE: Clarkia amoena¹³³; ROSACEAE: Rubus bifrons¹³⁶

269. Ceratina (Zadontomerus) pacifica H. S. Smith, 1907. County records: Chelan⁵⁸, Grant^1,2,4, Klickitat^2,3, Okanogan⁵⁸, Spokane^1,2, Whitman^1,2,58. Seasonality: Apr⁵⁸, May^1,2,58, Jun^1,2,58, Jul^1,2,58, Aug^1,2,3,58, Sep^1,2 (2014^1,2). Collections: BBSL, INHS, PCYU

270. ‡ Ceratina (Zadontomerus) sequoiae Michener, 1936. County records: Whitman⁵⁸. Seasonality: Apr⁵⁸, May⁵⁸ (1919⁵⁸)

Xylocopini

Genus Xylocopa Latreille

271. †* Xylocopa (Xylocopoides) virginica (Linnaeus, 1771). County records: Benton¹, King¹. Seasonality: Apr¹, May¹ (2024¹). Collections: iNaturalist

Colletidae: Colletinae: Colletini

Genus Colletes Latreille

272. Colletes compactus hesperius Swenk, 1906. County records: Walla Walla^37,84, Whitman^37,84,126, Yakima^37,84. Collections: NMNH. Holotype. USA, Washington, Whitman County, Almota

273. Colletes consors Cresson, 1868. County records: Clallam³, Okanogan^1,2,3,59, Yakima³. Seasonality: Jul^1,2,3 (2014³). Collections: BBSL, JRYA, SEMC. Floral records: HYDROPHYLLACEAE: Phacelia leptosepala^3,59

273a. Colletes consors pascoensis Cockerell, 1898. County records: Franklin^53,115, Okanogan^1,2, Walla Walla^1,2,3, Yakima^1,2,3,37,84. Seasonality: May^1,2,3, Jul^1,2,3,37,84, Aug^1,2 (2012^1,2). Collections: NMNH. Holotype. USA, Washington, Franklin County, Pasco. Floral records: HYDROPHYLLACEAE: Phacelia⁸⁴

274. ‡ Colletes delodontus Viereck, 1903. County records: Franklin¹¹⁵. Seasonality: May¹¹⁵ (1896¹¹⁵)

275. Colletes fulgidus Swenk, 1904. County records: Asotin^1,2,4, Benton^1,2, Garfield⁴⁶, Grant¹²⁶, Jefferson^1,2, Klickitat^1,2, Okanogan^1,2,3,4, San Juan^22,136, Spokane^1,2, Walla Walla^1,2, Whitman^6,126, Yakima¹²⁶. Seasonality: May^1,2, Jun^1,2,46, Jul^1,2, Aug^1,2,6, Sep^1,2, Oct^1,2 (2017¹³⁶). Collections: BBSL, PCYU, WSDA. Floral records: ASTERACEAE: Achillea millefolium^3,59, Anaphalis margaritacea⁵⁹, Crepis capillaris¹³⁶, Erigeron speciosus^3,59; CAPRIFOLIACEAE: Symphoricarpos albus¹³⁶; PLANTAGINACAE: Penstemon washingtonensis⁵⁹

275a. Colletes fulgidus fulgidus Swenk, 1904. County records: Benton^1,2,3, Clallam^1,2,3, Cowlitz^1,2,3, Ferry^1,2,3, Garfield^1,2,3, Grays Harbor^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Okanogan⁵⁹, San Juan^1,2, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,2,3. Seasonality: May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2 (2012^1,2). Collections: AMNH, BBSL, PWRC, SEMC. Floral records: FABACEAE: Onobrychis viciifolia³

276. Colletes gypsicolens Cockerell, 1897. County records: Benton^1,2,3, Franklin^1,2,3, Yakima^37,84. Seasonality: Sep^1,2,3, Oct^1,2 (1994^1,2,3). Collections: BBSL, SEMC

277. Colletes hyalinus Provancher, 1888. County records: Pacific^1,2,3, Pend Oreille^37,84, San Juan¹³⁶. Seasonality: Jul^1,2, Aug^1,2,3 (2017¹³⁶). Collections: BBSL. Floral records: ROSACEAE: Potentilla anserina ssp. pacifica¹³⁶

278. ‡ Colletes inaequalis Say, 1837. County records: Chelan^1,2,3,37,84, Douglas^1,2. Seasonality: May^1,2,3 (1960^1,2). Collections: SEMC

279. Colletes kincaidii Cockerell, 1898. County records: Asotin^1,2,4, Jefferson^1,2, San Juan¹³⁶, Spokane^1,2,53, Thurston^{1,2,3,53,84,115}, Whitman^1,2,3,53. Seasonality: May^1,2,3,4, Jun^1,2, Jul^1,2,3,53 (2017¹³⁶). Collections: BBSL, NMNH, PCYU, SEMC, UCRC. Holotype. USA, Washington, Thurston County, Olympia; 5 July 1946; Potentilla haliastris; Type No. 4270, USNM ENT 00534565. Floral records: ASTERACEAE: Cirsium arvense¹³⁶; CAPRIFOLIACEAE: Symphoricarpos albus¹³⁶; CARYOPHYLLACEAE: Spergularia macrotheca¹³⁶; ROSACEAE: Potentilla

280. Colletes lutzi Timberlake, 1943. County records: Benton^1,2, King⁵⁴, Spokane^1,2,3. Seasonality: May^1,2, Jun^1,2,3, Jul⁵⁴ (2015^1,2). Collections: BBSL

280a. Colletes lutzi interior Timberlake, 1951. County records: Benton^1,2,3, King^37,84, Kittitas^1,2,3,37, Whitman^37,84. Seasonality: Jul^1,2,3, Sep^1,2,3 (1995^1,2,3). Collections: BBSL, SEMC

281. Colletes nigrifrons Titus, 1900. County records: Chelan³, Okanogan^1,2,3,59, Skagit³. Seasonality: Jul^1,2, Aug^1,2,3 (2014³). Collections: BBSL, JRYA. Floral records: ASTERACEAE: Achillea millefolium⁵⁹; CELASTRACEAE: Parnassia fimbriata^3,59; CRASSULACEAE: Sedum lanceolatum⁵⁹; PLANTAGINACEAE: Penstemon washingtonensis⁵⁹; ROSACEAE: Potentilla gracilis^3,59

282. ‡ Colletes paniscus sculleni Timberlake, 1951. County records: Benton^1,2,3, Pierce^37,54,84, Yakima^1,2,3,37,84. Seasonality: May^1,2,3, Jul^1,2,3,54 (1949^1,2,3). Collections: SEMC

283. Colletes phaceliae Cockerell, 1906. County records: Ferry^1,2, Franklin^1,2,53, Thurston⁵³, Walla Walla^1,2,3. Seasonality: Apr^1,2, May⁵³, Jun^1,2,3,53, Jul⁵³, Aug^1,2 (2012^1,2). Collections: BBSL, PCYU, SEMC. Floral records: ONAGRACEAE: Chamerion angustifolium ssp. angustifolium⁵³

284. Colletes simulans Cresson, 1868. County records: Thurston¹¹⁵, Yakima¹²⁶. Seasonality: Jul¹¹⁵ (1896¹¹⁵). [= Colletes tegularis Swenk, 1905]

284a. Colletes simulans nevadensis Swenk, 1908. County records: Benton^1,2,3, Thurston¹³³. Seasonality: Jul¹³³, Sep^1,2,3 (2017¹³³). Collections: BBSL. Floral records: APIACEAE: Daucus carota¹³³; ASTERACEAE: Senecio³

285. Colletes slevini Cockerell, 1925. County records: Yakima^37,84

Hylaeinae: Hylaeini

Genus Hylaeus Fabricius

286. Hylaeus (Cephalylaeus) basalis (Smith, 1853). County records: King^1,2, Kitsap^1,2, Okanogan^1,2,3,59, San Juan⁵, Skagit^1,2, Thurston^1,2. Seasonality: May^1,2, Jun^1,2,3,5, Jul^1,2, Aug¹ (2014¹). Collections: BBSL, UCMC. Floral records: ASTERACEAE: Arnica sororia⁵⁹; BRASSICACEAE: Lepidium virginicum⁵; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; ROSACEAE: Rosa nutkana ssp. nutkana^3,59

287. Hylaeus (Hylaeus) annulatus (Linnaeus, 1758). County records: Chelan³, Clallam³, King^1,2,3, Okanogan^1,2,3,59, Skagit³. Seasonality: Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2014³). Collections: AMNH, BBSL, JRYA. [= Hylaeus ellipticus (Kirby, 1837)]. Floral records: ASTERACEAE: Agoseris glauca var. dasycephala⁵⁹, Anaphalis margaritacea⁵⁹, Taraxacum officinale^3,59; FABACEAE: Trifolium repens^3,59; GERANIACEAE: Geranium viscosissimum var. viscosissimum^3,59; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; ROSACEAE: Potentilla gracilis^3,59, Rosa nutkana ssp. nutkana⁵⁹

288. Hylaeus (Hylaeus) conspicuus (Metz, 1911). County records: Klickitat^1,2, Spokane^1,2, Whitman⁵⁵. Seasonality: Aug^1,2 (2011^1,2). Collections: BBSL, UCDC

289. Hylaeus (Hylaeus) granulatus (Metz, 1911). County records: Whitman³². Seasonality: May³², Jun³², Jul³² (2013³²)

290. †* Hylaeus (Hylaeus) leptocephalus (Morawitz, 1871). County records: Benton⁶, Douglas^1,2,3, Walla Walla^1,2, Yakima⁶. Seasonality: May⁶, Jun^1,2, Jul⁶, Aug^1,2,3 (2023⁶). Collections: BBSL, iNaturalist, WSDA. [= Hylaeus bisinuatus Förster, 1871]

291. Hylaeus (Hylaeus) mesillae (Cockerell, 1896). County records: Benton^1,2,6, Chelan⁶, Grant⁶, Okanogan⁶, Walla Walla^6,71, Yakima⁶. Seasonality: May⁶, Jun^1,2,6, Jul⁶, Aug⁶, Sep⁶ (2023⁶). Collections: BBSL, WSDA

291a. Hylaeus (Hylaeus) mesillae cressoni (Cockerell, 1907). County records: Benton^1,2,3, Walla Walla^1,2,3. Seasonality: Apr^1,2,3, Jun^1,2, Sep^1,2,3 (1997^1,2,3). Collections: BBSL

292. Hylaeus (Hylaeus) rudbeckiae (Cockerell and Casad, 1895). County records: Chelan⁶, Klickitat^1,2, Okanogan^1,2,3,6,59, Spokane^1,2. Seasonality: Jun^1,2, Jul^1,2,6, Aug^1,2,3,6, Sep^1,2 (2023⁶). Collections: BBSL, WSDA

293. †‡ Hylaeus (Hylaeus) verticalis (Cresson, 1869). County records: Kittitas^2,3. Seasonality: Jul^2,3 (1934^2,3). Collections: BBSL

294. †‡ Hylaeus (Paraprosopis) calvus (Metz, 1911). County records: Chelan^1,2,3. Seasonality: Jul^1,2,3 (1949^1,2,3). Collections: SEMC

295. Hylaeus (Paraprosopis) coloradensis (Cockerell, 1896). County records: Clallam³, Kittitas³, San Juan⁵⁵, Whitman⁵⁵. Seasonality: Aug³ (2014³). Collections: CAS, JRYA, UCMC, UCRC

296. Hylaeus (Paraprosopis) nevadensis (Cockerell, 1896). County records: Chelan³, King⁵⁵. Seasonality: Aug³ (2014³). Collections: JRYA

297. † Hylaeus (Paraprosopis) wootoni (Cockerell, 1896). County records: Chelan^1,2,3, Clallam³, Ferry^1,2,3, Pierce³, Spokane^1,2, Yakima⁶. Seasonality: Jun^1,2, Jul^1,2,3, Aug^1,2,3,6 (2023⁶). Collections: BBSL, JRYA, SEMC, UCRC, WSDA

298. ‡ Hylaeus (Prosopis) affinis (Smith, 1853). County records: Whitman⁸³. Seasonality: Jul⁸³ (1957⁸³). Collections: BBSL, SEMC, UCDC. Comments: Snelling (1966) indicates records from Pullman, WA in Garfield County; however, Pullman is located in Whitman County.

299. Hylaeus (Prosopis) episcopalis (Cockerell, 1896). County records: Clallam³, King⁸³, Klickitat^1,2,3, Pacific^1,2,3, Spokane^1,2, Whitman³. Seasonality: May^1,2, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2015^1,2). Collections: BBSL, JRYA, UCMC, UCRC

300. Hylaeus (Prosopis) modestus citrinifrons Say, 1837. County record: Chelan^1,2,3, Clallam³, Cowlitz^1,2,3, Grays Harbor^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3, Pierce^1,2,3, San Juan¹³⁶ Skagit³, Whatcom^1,2,3, Yakima^1,2,3. Seasonality: Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2017¹³⁶). Collections: BBSL, JRYA, SEMC, UCRC. Floral records: ASTERACEAE: Anaphalis margaritacea^3,59, Crepis capillaris¹³⁶, Taraxacum officinale^3,59; PLANTAGINACEAE: Penstemon confertus^3,59; ROSACEAE: Potentilla anserina ssp. pacifica¹³⁶, P. gracilis⁵⁹

301. †* Hylaeus (Spatulariella) punctatus (Brullé, 1832). County records: Whitman⁷, Yakima⁶. Seasonality: Aug^6,7 (2023⁶). Collections: WSDA

Halictidae: Halictinae: Halictini

Genus Agapostemon Guerin-Meneville

302. Agapostemon (Agapostemon) femoratus Crawford, 1901. County records: Adams^1,2,7, Asotin⁷, Benton^1,2,3,6,7,71, Chelan⁷, Douglas^1,2, Ferry^1,2,3, Franklin^1,2,3,7, Garfield^1,2,3,46, Grant^1,2,7, Island⁷, Kittitas^1,2,3, Mason⁷, Okanogan^1,2,3,7,59, Pacific^1,2,3, Spokane^1,2,3,7, Walla Walla^1,2,3,7,71, Whitman^1,2,3,7, Yakima⁷. Seasonality: Apr^1,2,3,7, May^1,2,3,7, Jun^1,2,3,46,7, Jul^1,2,3,6,7, Aug^1,2,3,7, Sep^1,2,3,7, Oct^1,2,7, Nov⁷ (2022⁶). Collections: BBSL, EMEC, iNaturalist, INHS, OSUC, SEMC, TAMU, WSDA, WSUC. Holotype. USA, Washington Territory. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Arnica cordifolia⁵⁹, Erigeron speciosus⁵⁹, Senecio integerrimus⁵⁹, Rhaponticum repens³; FABACEAE: Astragalus³; PLANTAGINACEAE: Penstemon washingtonensis⁵⁹

303. Agapostemon (Agapostemon) texanus Cresson, 1872. County records: Adams^1,2,7, Benton^1,2,3,7,71, Clallam^1,2,3, Douglas⁷, Franklin^1,2,7, Garfield^1,2,3,10,46, Grant⁷, Island^1,2,7, Jefferson^1,2, King^1,2,3,7, Kitsap^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Okanogan^1,2,3,4,7,59, Pacific^1,2,3, Pierce^1,2,7, San Juan^{1,2,3,5,6,7,124}, Skagit^7,10, Spokane^1,2,7, Thurston^1,2,3,7, Walla Walla^1,2,3,7,71, Whatcom^1,2,3,7, Whitman^2,3,7,8, Yakima^1,2,3,7. Seasonality: Mar^1,2, Apr^1,2,3,7, May^1,2,3,5,7, Jun^1,2,3,5,7,46, Jul^1,2,3,5,7, Aug^1,2,3,4,6,7, Sep^1,2,3,7, Oct^1,2,3,7 (2022^1,2). Collections: AMNH, BBSL, BugGuide, EMEC, FMNH, iNaturalist, OSUC, PWRC, SEMC, UCMC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral Records: ASTERACEAE: Anaphalis margaritacea⁵, Haplopappus⁸, Helianthus anuus⁸; CONVOLVULACEAE: Convolvulus⁸; FABACEAE: Astragalus racemosus³, Medicago sativa⁸; ROSACEAE: Rosa nutkana⁵

303a. Agapostemon (Agapostemon) angelicus Cockerell, 1924/texanus Cresson, 1872. County records: Asotin^1,2, Benton^1,2,3, Chelan^1,2,3, Columbia^1,2, Franklin^1,2, Garfield^1,2,3, Jefferson^1,2, King^1,2, Kitsap^1,2,3, Kittitas^1,2, Klickitat^1,2, Pierce^1,2,3, San Juan^6,136, Spokane^1,2,3, Stevens^1,2, Thurston¹³³, Walla Walla^1,2,3, Whatcom^1,2, Whitman². Seasonality: Mar^1,2, Apr^1,2, May^1,2,133, Jun^1,2,3,6,133, Jul^1,2,3,6,133, Aug^1,2,6, Sep^1,2, Oct^1,2 (2020¹³³). Collections: BBSL, SEMC, TAMU, WSDA. Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Crepis capillaris¹³³, Balsamorhiza deltoidea¹³³, Erigeron speciosus¹³³, Hypochaeris radicata^133,136, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Solidago missouriensis¹³³; BRASSICACEAE: Cakile maritima¹³⁶; CAPRIFOLIACEAE: Plectritis congesta¹³³; CONVOLVULACEAE: Calystegia soldanella¹³⁶; FABACEAE: Onobrychis arenaria³, Vicia satvia¹³³; HYPERICACEAE: Hypericum perforatum¹³³; MALVACEAE: Iliamna longisepala³; OROBANCHACEAE: Parentucellia viscosa¹³³; ONAGRACEAE: Clarkia amoena¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; ROSACEAE: Potentilla gracilis¹³³. Comments: Females of A. angelicus and A. texanus cannot be separated morphologically (Roberts 1973), so these uncertain records are combined here. No male A. angelicus have been recorded in Washington, suggesting these are most likely records of A. texanus.

304. Agapostemon (Agapostemon) virescens (Fabricius, 1775). County records: Benton^1,2,3,7, Chelan^1,2, Douglas³, Garfield⁷, Jefferson^1,2, King^1,2, Klickitat^1,2, Lewis^1,2, Okanogan^1,2,3,7,59, Skagit^1,2, Snohomish^1,2, Spokane^1,2,3,7, Stevens^1,2, Thurston^1,2,133, Walla Walla^1,2,3,7,71, Whitman^1,2,3,6,7,8, Yakima^1,2,7. Seasonality: Apr^1,2,7, May^1,2,7,133, Jun^1,2,3,7,133, Jul^{1,2,3,6,7,133}, Aug^1,2,3,6,7, Sep^1,2,3,7, Oct^1,2,7, Nov⁷ (2022^1,2). Collections: BBSL, BugGuide, iNaturalist, INHS, SEMC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Cirsium vulgare⁸, Erigeron speciosus¹³³, Eriophyllum lanatum¹³³, Gaillardia aristata^8,133, Helianthus anuus⁸, Hypochaeris radicata¹³³, Microseris laciniata¹³³, Solidago simplex¹³³, Taraxacum officinale¹³³; BRASSICACEAE: Lepidium campestre¹³³, Sisymbrium altissimum^3,59; FABACEAE: Vicia⁸, V. hirsuta¹³³; GENTIANACEAE: Gentiana calycosa⁸; GERANIACEAE: Geranium dissectum¹³³; HYPERICACEAE: Hypericum perforatum¹³³; IRIDACEAE: Sisyrinchium idahoense¹³³; ONAGRACEAE: Chamerion angustifolium¹³³, C. angustifolium ssp. angustifolium⁸, Clarkia amoena¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; ROSACEAE: Rosa⁸

Genus Halictus Latreille

305. Halictus (Nealictus) farinosus Smith, 1853. County records: Benton^1,2,3,71, Chelan^1,2,3, Douglas³, Grant^1,2,3, Klickitat^1,2, Okanogan^1,2,3,59, Pierce^1,2,3, Spokane^1,2,3,6, Stevens^1,2, Walla Walla^1,2,3,71, Whitman^{1,2,3,6,8,119}, Yakima^1,2,3,6,119. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2,3,6, Aug^1,2,3,6, Sep^1,2, Oct^1,2 (2022^1,2). Collections: BBSL, BugGuide, EMEC, iNaturalist, OSUC, SEMC, WSDA, WSUC. Floral records: APIACEAE: Lomatium⁸; ASTERACEAE: Achillea millefolium⁵⁹, Agoseris glauca var. dasycephala^3,59, Anaphalis margaritacea⁵⁹, Arnica cordifolia^3,59, Erigeron speciosus⁵⁹, Helianthus annuus⁸, Senecio triangularis⁵⁹, Solidago⁸; BRASSICACEAE: Brassica rapa⁸, Sisymbrium altissimum⁸; ROSACEAE: Malus domestica⁸

306. Halictus (Odontalictus) ligatus Say, 1837. County records: Adams^1,2, Benton^1,2,3,71, Chelan^1,2,3, Douglas^1,2, Grant^1,2,3, King^1,2,3, Klickitat^1,2,3, Okanogan^1,2,3,59, Spokane^1,2,3,6, Thurston^1,2, Walla Walla^1,2,3,71, Whitman^1,2,6,8, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3,6, Jul^1,2,3,6, Aug^1,2,3,6, Sep^1,2, Oct^1,2 (2022^1,2). Collections: BBSL, BugGuide, FMNH, iNaturalist, WSDA, WSUC. Floral records: ASTERACEAE: Anaphalis margaritacea^3,59, Cirsium arvense⁸, Haplopappus⁸, Helianthus annuus⁸, Solidago⁸

307. Halictus (Protohalictus) rubicundus (Christ, 1791). [= Halictus lerouxii var. ruborum Cockerell, 1898]. County records: Benton^1,2, Chelan^1,2,3, Clallam^1,2,3, Clark^1,2,3, Cowlitz^1,2,3, Douglas^1,2, Garfield⁴⁶, Jefferson^1,2,3, King^1,2,3,119, Kitsap^1,2,3, Kittitas^2,3, Klickitat^1,2, Mason^1,2,3, Okanogan^1,2,3,59, Pacific^1,2,3, Pierce^1,2,3, San Juan^{1,2,3,6.22,124,136}, Skagit^1,2,3,10,124, Snohomish^1,2,3, Spokane^1,2,3,6, Stevens^1,2,3, Thurston^1,2,3,6,133, Walla Walla^1,2,3, Whatcom^1,2,3,6, Whitman^1,2,6,8. Seasonality: Feb^1,2, Mar^1,2,3, Apr^1,2,133, May^1.2,133, Jun^1,2,3,6,133, Jul^1,2,3,6, Aug^1,2,3,6, Sep^1,2,3, Oct^1,2 (2022^1,2). Collections: AMNH, BBSL, BugGuide, FMNH, iNaturalist, JRYA, PWRC, TAMU, WSDA, WSUC. Floral records: APIACEAE: Lomatium⁸; ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Achillea millefolium⁵⁹, Cirsium arvense⁸, Erigeron speciosus⁵⁹, Hypochaeris radicata¹³⁶, Senecio triangularis^3,59, Taraxacum officinale^8,133; BRASSICACEAE: Sisymbrium altissimum^3,59; CAMPANULACAEAE: Campanula rotundifolia⁵⁹; CONVOLVULACEAE: Calystegia soldanella¹³⁶; CRASSULACEAE: Sedum lanceolatum⁵⁹; FABACEAE: Lupinus sericeus⁵⁹, Trifolium pratense³, T. repens^8,59; OROBANCHACEAE: Parentucellia viscosa¹³³; RANUNCULACEAE: Ranunculus⁸; ROSACEAE: Fragaria virginiana¹³³, Rubus bifrons¹³⁶

308. Halictus (Seladonia) confusus Smith, 1853. County records: Chelan³, Clallam³, Jefferson^1,2, King^1,2,3, Klickitat^1,2, Pacific^1,2, Pierce^1,2,3, San Juan^5,6, Spokane^1,2, Thurston^1,2,3,133, Whatcom^1,2,3, Whitman⁶. Seasonality: Apr¹³³, May^1,2,5,133, Jun^1,2,3,6,133, Jul^1,2,3,6,133, Aug^1,2,3,6 (2020¹³³). Collections: AMNH, BBSL, BugGuide, EMEC, iNaturalist, JRYA, OSUC, PCYU, SEMC, WSDA. Floral records: ASPARAGACEAE: Brodiaea coronaria¹³³, Camassia quamash¹³³; ASTERACEAE: Crepis capillaris¹³³, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³; BRASSICACEAE: Lepidium campestre¹³³, Teesdalia nudicaulis¹³³; CARYOPHYLLACEAE: Cerastium arvense¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; FABACEAE: Lupinus bicolor¹³³, Trifolium repens¹³³; IRIDACEAE: Sisyrinchium idahoense¹³³; LAMIACEAE: Prunella vulgaris¹³³; PLANTAGINACEAE: Collinsia grandiflora¹³³; POLEMONIACEAE: Gilia capitata¹³³; ROSACEAE: Fragaria virginiana¹³³; Potentilla gracilis¹³³

309. Halictus (Seladonia) tripartitus Cockerell, 1895. County records: Benton^1,2,3,71, Clallam^1,2, Douglas^1,2, Jefferson^1,2, Kittitas^2,3, Klickitat^1,2, Okanogan^1,2,3,59, San Juan^{1,2,3,5,6,124}, Spokane^1,2,3, Stevens^1,2, Thurston¹³³, Walla Walla^1,2,3,71, Whitman^1,2,3,6,8, Yakima^1,2. Seasonality: Mar^1,2, Apr^1,2, May^1,2,3,133, Jun^1,2,3,133, Jul^1,2,3,5,6, Aug^1,2,3,6, Sep^1,2, Oct^1,2 (2022^1,2). Collections: AMNH, BBSL, BugGuide, iNaturalist, INHS, TAMU, UMNH, WSDA, WSUC. Floral records: APIACEAE: Lomatium⁸; ASPARAGACEAE: Triteleia hyacinthina¹³³; ASTERACEAE: Cirsium arvense⁸, Erigeron speciosus¹³³, Eriophyllum lanatum¹³³, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Solidago⁸, Taraxacum officinale⁸; CAMPANULACEAE: Campanula rotundifolia¹³³; FABACEAE: Trifolium repens⁸; OROBANCHACEAE: Parentucellia viscosa¹³³; PLANTAGINACEAE: Collinsia parviflora⁸; PLUMBAGINACEAE: Armeria maritima¹³³; RANUNCULACEAE: Ranunculus⁸; ROSACEAE: Fragaria virginiana¹³³, Potentilla gracilis^3,59,133, Rosa⁸, Rubus ulmifolius⁵

310. † Halictus (Seladonia) virgatellus Cockerell, 1901. County records: Chelan³, Clallam³, Pierce^1,2,3, Stevens^1,2, Whatcom³. Seasonality: May^1,2,3, Jun^1,2, Jul^1,2, Aug³ (2014^1,2,3). Collections: BBSL, EMEC, JRYA

Genus Lasioglossum Curtis

311. † Lasioglossum (Dialictus) albipenne (Robertson, 1890). County records: San Juan^1,2,3, Whitman⁷. Seasonality: May⁷, Jun⁷, Jul^1,2,7, Aug⁷, Sep⁷ (2011^1,2). Collections: PWRC, WSUC

312. Lasioglossum (Dialictus) albohirtum (Crawford, 1907). County records: Adams⁷, Benton^1,2,3,6,7,71, Columbia^1,2,4,38, Grant⁷, Okanogan⁷, Pierce⁷, Walla Walla^1,2,3,7,71, Whitman⁷, Yakima^7,38. Seasonality: Apr⁷, May^1,2,4,6,7,38, Jun⁷, Jul^1,2,7, Aug^1,2,3,7, Sep^1,2,3,7, Oct^1,2,7 (2022⁶). Collections: BBSL, PCYU, WSDA, WSUC. Floral records: FABACEAE: Melilotus officinalis³⁸; Ericameria nauseosa³⁸, Eriogonum³⁸

313. † Lasioglossum (Dialictus) brunneiventre (Crawford, 1907). County records: Benton⁷, Walla Walla⁷, Whitman⁷, Yakima⁷. Seasonality: May⁷, Jun⁷, Jul⁷, Aug⁷, Sep⁷, Oct⁷ (2014⁷). Collections: WSUC

314. † Lasioglossum (Dialictus) cressonii (Robertson, 1890). County records: King^1,2,3, Skagit⁷, Snohomish⁷, Stevens⁷, Whatcom^6,7, Whitman⁷. Seasonality: Apr⁷, Jun⁷, Jul^1,2,3,6, Aug⁶, Sep⁷, Oct⁷ (2011^1,2,3). Collections: AMNH, WSDA, WSUC

315. Lasioglossum (Dialictus) dashwoodi Gibbs, 2010. County records: Garfield³⁸, Klickitat⁷, Okanogan³⁸, Spokane⁷, Whitman⁷, Yakima⁷. Seasonality: May^7,38, Jun⁷, Jul⁷, Aug³⁸ (2022⁷). Collections: BBSL, PCYU, WSUC. Allotype. USA, Washington, Okanogan County, 1 mi E Muckamuck Hill, 48.601661°N, -119.765108°W; 9 August 2004; J Wilson. Paratype. USA, Washington, Okanogan County, 25 km W Clarkston, Hwy 12, 805 m; 29 May 2007; Gibbs and Sheffield

316. † Lasioglossum (Dialictus) diversopunctatum (Ellis, 1914). County records: Benton⁷, Yakima⁷. Seasonality: Jun⁷, Jul⁷, Aug⁷ (2014⁷). Collections: WSUC

317. Lasioglossum (Dialictus) helianthi (Cockerell, 1916). County records: Adams⁷, Benton⁷, Grant⁷, Grays Harbor⁶, Okanogan⁷, Pierce¹²², Walla Walla⁷, Whitman⁷, Yakima⁷. Seasonality: Apr^7,122, May⁷, Jun⁷, Jul⁷, Aug^6,7 (2020⁶). Collections: PCYU, WSDA, WSUC. [= Lasioglossum (Dialictus) imbrex Gibbs, 2010].

318. † Lasioglossum (Dialictus) hyalinum (Crawford, 1907). County records: Adams⁷, Benton⁷, Chelan⁷, Grant⁷, Yakima⁷. Seasonality: Mar⁷, Apr⁷, May⁷, Jun⁷, Jul⁶, Aug⁷, Oct⁷ (2022⁶). Collections: WSDA, WSUC

319. Lasioglossum (Dialictus) incompletum (Crawford, 1907). County records: Asotin⁷, Benton^1,2,3,7,71, Chelan⁷, Garfield^1,2,3,4, Grant⁷, Island⁷, Kittitas⁷, Klickitat⁷, San Juan^1,2,3,124, Spokane⁷, Walla Walla^1,2,3,6,7,71, Whitman⁷, Yakima⁷. Seasonality: Mar⁷, Apr⁷, May^1,2,3,4,7, Jun^1,2,7, Jul^1,2,6,7, Aug^1,2,3,7, Sep^1,2,7, Oct^1,2,7 (2022⁶). Collections: BBSL, PCYU, PWRC, WSDA, WSUC

320. Lasioglossum (Dialictus) knereri Gibbs, 2010. County records: Asotin⁷, Clark⁷, Island⁷, King^1,2,3, Klickitat⁷, Okanogan^1,2,3,38, San Juan^1,2,3,7,124, Skagit⁷, Spokane⁷, Whitman⁷, Yakima⁷. Seasonality: Apr⁷, May^1,2,7, Jun^1,2,3,7, Jul^1,2,38,7, Aug^1,2,3,7 (2011^1,2,124). Collections: BBSL, PWRC, WSUC. Floral records: BRASSICACEAE: Smelowskia calycina³, CAMPANULACEAE: Campanula rotundifolia³⁸

321. Lasioglossum (Dialictus) laevissimum (Smith, 1853). County records: Benton⁷, Clark⁷, Grant⁷, Grays Harbor⁶, Island⁷, King⁷, Okanogan⁷, Pacific⁷, Pierce^6,7, San Juan⁶, Skagit¹⁰, Snohomish⁷, Stevens⁷, Whatcom⁶, Whitman⁷. Seasonality: Apr⁷, May⁷, Jun^6,7, Jul^6,7, Aug^6,7, Sep^6,7, Oct⁷ (2021⁶). Collections: WSDA, WWUC, WSUC

322. † Lasioglossum (Dialictus) longicorne (Crawford, 1907). County records: San Juan^1,2. Seasonality: May^1,2 (2011^1,2). Collections: PWRC. Comments: This species plausibly occurs in Washington, but the specimens were not seen by the authors and its taxonomy is known to be uncertain (the taxon is part of the difficult Lasioglossum viridatum species complex.)

323. Lasioglossum (Dialictus) macroprosopum Gibbs, 2010. County records: Benton⁷, Kittitas⁷, Skagit¹⁰, Spokane⁷, Walla Walla⁷, Whitman⁷, Yakima⁷. Seasonality: Mar⁷, Apr⁷, May⁷, Jun⁷, Jul⁷, Aug⁷, Oct⁷ (2014⁷). Collections: WSUC, WWUC

324. Lasioglossum (Dialictus) marinense (Michener, 1936). County records: Asotin⁷, Okanogan^1,2,3,38,59, San Juan^1,2,3, Stevens⁷. Seasonality: Jun^1,2,3,7,38, Jul^1,2,7, Aug^1,2,3,38 (2011^1,2). Collections: BBSL, PCYU, PWRC, WSUC. Floral records: ASTERACEAE: Taraxacum officinale⁵⁹; ROSACEAE: Rosa nutkana ssp. nutkana³

325. Lasioglossum (Dialictus) nevadense (Crawford, 1907). County records: Asotin⁷, Benton⁷, Chelan⁷, Clark⁷, Cowlitz⁷, Okanogan^{1,2,3,7,38,59}, San Juan^1,2,3,124, Spokane⁷, Walla Walla⁷, Whitman⁷, Yakima⁷. Seasonality: Apr⁷, May^1,2,7, Jun^1,2,7,38, Jul^1,2,3,7,38, Aug^1,2,3,7 (2014⁷). Collections: BBSL, PCYU, PWRC, WSUC. Floral records: ASTERACEAE: Cirsium vulgare³

326. † Lasioglossum (Dialictus) nigroviride (Graenicher, 1911). County records: Chelan³, Pend Oreille⁷. Seasonality: Jun⁷, Aug³ (2014³). Collections: JRYA, WSUC

327. † Lasioglossum (Dialictus) novascotiae (Mitchell, 1960). County records: Benton⁷, Okanogan⁷, Spokane⁷, Stevens⁷, Walla Walla⁷, Whatcom⁷, Whitman⁷, Yakima⁷. Seasonality: Apr⁷, May⁷, Jun⁷, Jul⁷, Aug⁷, Sep⁷ (2013⁷). Collections: WSUC. Floral records: ASTERACEAE: Taraxacum officinale⁷; FABACEAE: Medicago sativa⁷

328. Lasioglossum (Dialictus) pacatum (Sandhouse, 1924). County records: Okanogan^1,2,3,59, San Juan^1,2,3,124. Seasonality: May^1,2, Jun^1,2, Jul^1,2,3, Aug^1,2,3 (2011^1,2,124). Collections: BBSL, PWRC. Floral records: ASTERACEAE: Taraxacum officinale³

329. † Lasioglossum (Dialictus) pallidellum (Ellis, 1914). County records: Benton⁷, Grant⁷. Seasonality: May⁷, Jul⁷, Oct⁷ (1995⁷). Collections: WSUC. Floral records: SARCOBATACEAE: Sarcobatus vermiculatus⁷

330. Lasioglossum (Dialictus) perdifficile (Cockerell, 1895). County records: Benton^1,2,3,71, Walla Walla^1,2,3,71. Seasonality: Aug^1,2, Sep^1,2,3 (1997^1,2,3). Collections: BBSL. Comments: Lasioglossum perdifficile belongs to a difficult complex that includes multiple undescribed species. Washington records of this species (originally described from New Mexico) are likely misidentifications or based on over-inclusive species concepts. Several Washington specimens have been examined and they are believed to comprise two species, one of which may be a morphological variant within L. yukonae Gibbs, 2010, and the other of which is probably undescribed. Further taxonomic work is needed to resolve this complex.

331. †‡ Lasioglossum (Dialictus) platyparius (Robertson, 1895). County records: Whitman⁷. Seasonality: May⁷ (1917⁷). Collections: WSUC. Comments: This social parasite is primarily distributed east of the Rocky Mountains. The Washington record, based on a single specimen collected at Wawawai in 1917, represents a significant and unexpected range extension both for the species and for socially parasitic Dialictus in general. But considering that Whitman County is one of the most well-collected regions in Washington and L. platyparius has not been re-collected in over 100 years, it is possible that the species is not permanently established in Washington, or it has been extirpated.

332. Lasioglossum (Dialictus) prasinogaster Gibbs, 2010. County records: Adams⁷, Benton⁷, Garfield³⁸, Franklin⁷, Grant⁷, Klickitat⁷, Okanogan^1,2,3,59, Spokane⁷, Walla Walla⁷, Whitman⁷, Yakima⁷. Seasonality: Apr⁷, May^7,38, Jun⁷, Jul^1,2,3,7, Aug⁷, Sep⁷ (2013⁷). Collections: BBSL, PCYU, WSUC. Floral records: ASTERACEAE: Chrysothamnus⁷, Taraxacum³⁸

333. Lasioglossum (Dialictus) pruinosum (Robertson, 1892). County records: Benton^1,2,3,7,71, Douglas⁷, Garfield⁷, Okanogan⁷, Walla Walla^1,2,3,7,71, Whitman⁷, Yakima⁷. Seasonality: Apr⁷, May^1,2,7, Jun^1,2,7, Jul^1,2,3,7, Aug^1,2,3,7, Sep^1,2,7, Oct^1,2 (2014⁷). Collections: BBSL, WSUC

334. Lasioglossum (Dialictus) punctatoventre (Crawford, 1907). County records: Benton⁷, Okanogan^1,2,3,59, Spokane⁷, Whitman⁷. Seasonality: May⁷, Jun⁷, Jul^1,2,3,7, Aug^1,2,7 (2011^1,2). Collections: BBSL, PWRC, WSUC. Floral records: ROSACEAE: Potentilla gracilis⁵⁹

335. † Lasioglossum (Dialictus) reasbeckae Gibbs, 2010. County records: Thurston^1,2,4. Seasonality: May⁷, Jun^1,2,4 (2009^1,2,4). Collections: PCYU, WSUC. Comments: A specimen in WSUC labeled “Rock Creek” was probably collected in Spokane County, based on other specimens from the collector (Robin D. Gray). However, there are at least 33 Rock Creeks in Washington, so the exact location is unknown.

336. Lasioglossum (Dialictus) ruidosense (Cockerell, 1897). County records: Asotin⁷, Benton⁷, Clallam³, Clark⁷, Grant⁷, Okanogan^1,2,3,59, Skagit⁷, Spokane⁷, Stevens⁷, Thurston^1,2,4,7, Whitman⁷. Seasonality: May⁷, Jun^1,2,3,4,7, Jul⁷, Aug^1,2,3,7 (2014³). Collections: BBSL, JRYA, PCYU, WSUC. Floral records: ASTERACEAE: Achillea millefolium³, Taraxacum officinale⁵⁹

337. Lasioglossum (Dialictus) sandhousiellum Gibbs, 2010. County records: Okanogan^3,59. Seasonality: Jul³ (2004^3,59). Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Taraxacum officinale⁵⁹; POLEMONIACEAE: Ipomopsis aggregata ssp. aggregata⁵⁹

338. Lasioglossum (Dialictus) sedi (Sandhouse, 1924). County records: Asotin⁷, Chelan⁷, King^1,2,3, Klickitat^1,2,3, Okanogan^1,2,3,38,59, Whitman⁷, Yakima⁷. Seasonality: Apr^1,2,3,7, May⁷, Jun^1,2,3,7,38, Jul^1,2,3,7,38, Aug^1,2 (2004^1,2,38,59). Collections: AMNH, BBSL, PCYU, WSUC. Floral records: ASTERACEAE: Erigeron speciosus^3,59; CAMPANULACEAE: Campanula rotundifolia^3,38,59; CELASTRACEAE: Parnassia fimbriata⁵⁹; CRASSULACEAE: Sedum lanceolatum⁵⁹, S. stenopetalum³⁸; HYDROPHYLLACEAE: Phacelia leptosepala³⁸; PLANTAGINACEAE: Penstemon davidsonii var. davidsonii⁵⁹; ROSACEAE: Rosa nutkana ssp. nutkana^3,59

339. Lasioglossum (Dialictus) tegulariforme (Crawford, 1907). County records: Benton^1,2,3,71, Grant⁷, Stevens¹²², Walla Walla^1,2,3,71, Whitman^1,2. Seasonality: May^1,2, Jun^1,2, Jul⁷, Aug^1,2,3,122, Sep^1,2, Oct^1,2 (2011¹²²). Collections: BBSL, EMEC, FWSE, WSUC. Comments: Prior to 2010, L. helianthi was considered a synonym of L. tegulariforme (Gibbs 2010 [as L. imbrex]; Gardner and Gibbs 2022). As the specimen from Whitman County was collected prior to 2010 and has not been examined, it is possible that this specimen could be L. helianthi.

340. Lasioglossum (Dialictus) tenax (Sandhouse, 1924). County records: Okanogan^1,2,3,59, Pierce^1,2,4, Thurston^1,2,4. Seasonality: May^1,2,4, Jun^1,2,3, Jul^1,2,3, Aug^1,2,4 (2009^1,2,4). Collections: BBSL, PCYU. Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Cirsium vulgare⁵⁹; CAMPANULACEAE: Campanula rotundifolia³. Comments: All Washington specimens of L. tenax that have been examined so far have turned out to be an undescribed species closely related to L. tenax. This species is distinguished from the true L. tenax by the smooth, shiny, sparsely punctate mesepisternum (contrasted with the dull, rugulose mesepisternum of L. tenax). It seems likely that the true L. tenax does not occur in Washington, and all published records actually correspond to this undescribed species. The undescribed species will be described in a forthcoming publication.

341. Lasioglossum (Dialictus) zephyrus (Smith, 1853). County records: Benton⁷, Clark^1,2,79, Spokane⁷, Walla Walla⁷, Whitman^1,2,7,79, Yakima⁷. Seasonality: Apr⁷, May^1,2,7,79, Jun⁷, Jul^1,2,7,79, Aug⁷, Sep⁷, Oct⁷ (2014⁷). Collections: CAS, UCDC, WSUC

342. † Lasioglossum (Evylaeus) argemonis (Cockerell, 1897). County records: Asotin⁷, Chelan⁷, Columbia⁷, Whitman⁷, Yakima⁷. Seasonality: Apr⁷, May⁷, Jul⁷ (1980⁷). Collections: WSUC

343. † Lasioglossum (Evylaeus) robustum (Crawford, 1907). County records: Clark⁷. Seasonality: Jul⁷ (1970⁷). Collections: WSUC

344. † Lasioglossum (Hemihalictus) aspilurus (Cockerell, 1925). County records: Benton⁷, Walla Walla⁷, Whitman⁷. Seasonality: Apr⁷, May⁷ (1973⁷). Collections: WSUC

345. †* Lasioglossum (Hemihalictus) buccale (Pérez, 1903). County records: Spokane⁷. Seasonality: Jul⁷, Aug⁷ (1970⁷). Collections: WSUC

346. † Lasioglossum (Hemihalictus) glabriventre (Crawford, 1907). County records: Benton⁷, Cowlitz⁷, Garfield⁷, Klickitat^1,2, Spokane^1,2,7, Walla Walla⁷, Whitman⁷, Yakima⁷. Seasonality: May^1,2,7, Jun^1,2,7, Jul^1,2,7, Aug^1,2,7, Sep^1,2 (2015^1,2). Collections: BBSL, WSUC

347. Lasioglossum (Hemihalictus) inconditum (Cockerell, 1916). County records: Asotin⁷, Clallam⁷, Cowlitz⁷, Island^7,80, King⁸⁰, Klickitat⁷, Lewis⁷, San Juan⁷, Skagit⁷, Spokane⁷, Stevens⁷, Thurston⁸⁰, Whitman⁸⁰, Yakima⁷. Seasonality: Apr⁷, May^7, Jun⁷, Jul⁷, Aug⁷, Sep⁷ (1985⁷). Collections: WSUC

348. Lasioglossum (Hemihalictus) kincaidii (Cockerell, 1898). County records: Benton⁷, Clark⁷, Grant⁷, Jefferson⁷, King⁷, Klickitat^1,2, Pacific⁷, Pierce^1,2,4, Spokane^1,2, Thurston¹¹⁹, Walla Walla^1,2,7, Whitman⁷, Yakima⁷. Seasonality: Apr^1,2, May^1,2,7, Jun^1,2,7, Jul^1,2,4,7, Aug⁷ (2015^1,2). Collections: BBSL, PCYU, WSUC. [= Halictus kincaidii Cockerell, 1898]

349. Lasioglossum (Hemihalictus) ovaliceps (Cockerell, 1898). County records: Asotin⁷, Chelan⁷, Clark⁷, King^1,2,3, Lewis⁷, Okanogan⁷, San Juan²², Snohomish^1,2,3, Thurston^1,2,7, Whitman⁷, Yakima^1,2,4,7. Seasonality: Apr^1,2,7, May^1,2,3,4,7, Jun^1,2,7, Jul^1,2,7, Aug^1,2,3,7, Sep⁷, Oct^1,2, Nov^1,2 (2022^1,2). Collections: iNaturalist, PCYU, WSUC. Floral records: ASTERACEAE: Hypochaeris radicata³

350. † Lasioglossum (Hemihalictus) sequoiae (Michener, 1936). County records: San Juan^1,2,3. Seasonality: May^1,2, Jul^1,2 (2011^1,2). Collections: PWRC

351. †* Lasioglossum (Hemihalictus) villosulum (Kirby, 1802). County records: King⁷, Snohomish⁷. Seasonality: May⁷, Jun⁷, Jul⁷ (2019⁷). Collections: WSUC

352. Lasioglossum (Lasioglossum) anhypops McGinley, 1986. County record: Asotin⁸¹, Chelan^3,7, Klickitat^1,2, Okanogan^1,2,3,59, Pierce^1,2,3,81, Stevens^1,2, Whitman⁸¹. Seasonality: May^1,2,7, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2014^1,2,3). Collections: BBSL, JRYA, OSUC, WSUC. Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Anaphalis margaritacea^3,59; FABACEAE: Lupinus sericeus^3,59

353. Lasioglossum (Lasioglossum) athabascense (Sandhouse, 1933). County records: Asotin⁷, Island⁸¹, King⁸¹, Okanogan^1,2,3,59, Pend Oreille^7,81, San Juan^1,2,3,124, Stevens^7,81, Whitman⁷. Seasonality: May^1,2, Jun^1,2,3,7, Jul^1,2,7, Sep⁷ (2011^1,2,124). Collections: BBSL, PWRC, WSUC. Floral records: ROSACEAE: Potentilla gracilis^3,59

354. Lasioglossum (Lasioglossum) colatum (Vachal, 1904). County records: Asotin⁸¹, King⁸¹, Skagit^1,2,3, Stevens⁸¹, Thurston⁸¹, Walla Walla^7,81, Whitman^7,81. Seasonality: May⁷, Jun⁷, Jul⁷, Aug^1,2,7 (2013⁷). Collections: PWRC, WSUC

355. Lasioglossum (Lasioglossum) egregium (Vachal, 1904). County records: Chelan⁷, Columbia⁷, Cowlitz⁷, Grant⁷, Island⁷, Klickitat^1,2, Lincoln⁷, Mason^7,81, Okanogan^{1,2,3,7,59,81}, Pend Oreille^7,81, San Juan^1,2,3,124, Spokane^1,2,7,81, Thurston¹³³, Walla Walla^1,2,7, Whatcom³, Whitman^{1,2,3,4,6,7,81}, Yakima⁷. Seasonality: Apr⁷, May^1,2,7,133, Jun^1,2,6,7,133, Jul^1,2,3,4,6,7, Aug^3,6,7, Sep^1,2, Oct^1,2, Nov⁷ (2018¹³³). Collections: BBSL, JRYA, PWRC, WSDA, WSUC. Floral records: ASTERACEAE: Leucanthemum vulgare¹³³; PLUMBAGINACEAE: Armeria maritima¹³³

356. Lasioglossum (Lasioglossum) heterorhinus (Cockerell, 1930). County records: Thurston¹³³. Seasonality: May¹³³, Jul¹³³ (2019¹³³). Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Erigeron speciosus¹³³

357. Lasioglossum (Lasioglossum) mellipes (Crawford, 1907). County records: Douglas⁷, Island^7,81, King⁸¹, Kittitas^2,3,81, Klickitat^1,2, Pierce^1,2,3, San Juan^1,2,124,136, Stevens^1,2, Walla Walla^1,2. Seasonality: Apr^1,2,7, May^1,2,7, Jun^1,2, Jul^1,2,3 (2017¹³⁶). Collections: BBSL, PWRC, WSUC

358. Lasioglossum (Lasioglossum) olympiae (Cockerell, 1898). County records: Asotin^7,81, Island^7,81, Klickitat^1,2, Pierce⁸¹, San Juan^{1,2,3,5,6,7,81,124,136}, Spokane^1,2,81, Thurston^{81,119,130,133}, Walla Walla⁸¹, Whitman^2,6, Yakima⁷. Seasonality: May^1,2,5,133, Jun^1,2,6,7,133, Jul^1,2, Aug^6,7, Sep^1,2 (2020¹³³). Collections: BBSL, NMNH, PWRC, WSDA, WSUC. [= Halictus olympiae Cockerell, 1898]. Holotype. USA, Washington, Thurston County, Olympia; 26 June 1896; USNM Type No. 29420. [= Halictus olympiae var. subangustatus Crawford, 1906]. Floral records: APIACEAE: Heracleum sphondylium ssp. montanum⁵, Lomatium pugetensis¹³³; ASTERACEAE: Microseris laciniata¹³³; GROSSULARIACEAE: Ribes divaricatum¹³⁶; PLUMBAGINACEAE: Armeria maritima¹³³; POLEMONIACEAE: Gilia capitata¹³³; ROSACEAE: Potentilla gracilis¹³³

359. Lasioglossum (Lasioglossum) pacificum (Cockerell, 1898). County records: Clark^7,81, Island^7,81, Jefferson^1,2, King^7,81,119, Kitsap⁸¹, Pacific^1,2,3,81, Pierce^1,2,4,81, San Juan^{1,2,3,5,7,124}, Skagit¹⁰, Thurston^81,119,133, Yakima^1,2,3. Seasonality: Apr⁷, May^1,2,5,7,133, Jun^1,2,133, Jul^1,2,3,5, Aug^1,2,3,4, Sep⁷ (2020¹³³). Collections: BBSL, EMEC, PCYU, PWRC, SEMC, WSUC. [= Halictus pacificus Cockerell, 1898]. Lectotype. USA, Washington, Thurston County, Olympia; 24 June 1895. Floral records: APIACEAE: Heracleum sphondylium ssp. Montanum⁵; ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Crepis capillaris⁵, Microseris laciniata¹³³; BRASSICACEAE: Lepidium campestre¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; FABACEAEA: Lupinus albicaulis¹³³, L. lepidus¹³³; LAMIACEAE: Prunella vulgaris¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; RANUNCULACEAE: Ranunculus californicus⁵; ROSACEAE: Potentilla gracilis¹³³; VIOLACEAE: Viola adunca¹³³

360. Lasioglossum (Lasioglossum) pavonotus (Cockerell, 1925). County records: Grays Harbor^1,2,3,81, Pacific^1,2,3,7,81. Seasonality: Jun⁷, Jul^1,2,3,7, Aug⁷ (1976⁷). Collections: BBSL, SEMC, WSUC

361. Lasioglossum (Lasioglossum) sisymbrii (Cockerell, 1895). County records: Asotin⁷, Benton^1,2,7, Chelan^7,81, Clark^7,81, Columbia⁷, Garfield^7,81, Grant^1,2, Island⁷, King^1,2,81, Kittitas², Klickitat^1,2,81, Okanogan^1,2,3,59,81, San Juan^1,2,3,81,124, Skagit^1,2,3,81,124, Spokane^1,2,3,7,81, Stevens⁸¹, Thurston^81,119,133, Walla Walla^1,2,3,7,81, Whitman^1,2,3,6,7,81, Yakima^7,81. Seasonality: Apr^1,2,7, May^1,2,3,7,133, Jun^1,2,3,7,133, Jul^1,2,3,7, Aug^1,2,6,7, Sep^1,2,7, Oct⁷ (2022^1,2). Collections: BBSL, BugGuide, iNaturalist, PWRC, TAMU, WSDA, WSUC. [= Halictus sisymbrii Cockerell, 1895]. Floral records: ASPARAGACEAE: Camassia quamash¹³³, Triteleia hyacinthina¹³³; ASTERACEAE: Balsamorhiza deltoidea¹³³, Crepis capillaris¹³³, Eriophyllum lanatum¹³³, Leucanthemum vulgare¹³³, Microseris laciniata¹³³; BRASSICACEAE: Sisymbrium altissimum^3,59; CAMPANULACEAE: Campanula rotundifolia¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³, Symphoricarpos albus¹³³; FABACEAE: Lupinus albicaulis¹³³; HYPERICACEAE: Hypericum perforatum¹³³; LAMIACEAE: Prunella vulgaris¹³³; ONAGRACEAE: Chamerion angustifolium¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; ROSACEAE: Potentilla gracilis¹³³

362. Lasioglossum (Lasioglossum) titusi (Crawford, 1902). County records: Benton^1,2, Chelan⁷, Grays Harbor^7,81, Island^7,81, Klickitat^1,2,81, Pierce^1,2,3,81, Spokane^1,2, Thurston^7,81,133, Walla Walla^1,2,3,81, Whitman^2,7,81, Yakima⁷. Seasonality: Apr^1,2,133, May^1,2,3,7,133, Jun^1,2,3,7,133, Jul^1,2,7,133, Aug^1,2, Sep^1,2, Oct^1,2 (2020¹³³). Collections: BBSL, SEMC, WSUC. Floral records: ASPARAGACEAE: Camassia quamash¹³³, Triteleia hyacinthina¹³³; ASTERACEAE: Achillea millefolium¹³³, Balsamorhiza deltoidea¹³³, Crepis capillaris¹³³, Erigeron speciosus¹³³, Eriophyllum lanatum¹³³, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³, Microseris laciniata¹³³, Solidago simplex¹³³, Taraxacum officinale¹³³; BRASSICACEAE: Teesdalia nudicaulis¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; CARYOPHYLLACEAE: Cerastium arvense¹³³; PLUMBAGINACEAE: Armeria maritima¹³³; RANUNCULACEAE: Ranunculus occidentalis¹³³

363. Lasioglossum (Lasioglossum) trizonatum (Cresson, 1874). County records: Adams⁸¹, Benton^1,2,7, San Juan^1,2,3,124, Stevens^1,2, Thurston¹¹⁹, Walla Walla⁷, Whatcom³, Whitman^2,3,7,81, Yakima^7,81. Seasonality: Apr^1,2,7, May^1,2,7, Jun^1,2,7, Jul⁷, Aug^1,2,3,7 (2015^1,2). Collections: BBSL, JRYA, PWRC, WSUC. [= Halictus trizonatus Cresson, 1874]

364. * Lasioglossum (Leuchalictus) leucozonium (Schrank, 1781). County records: Thurston¹¹⁹. [= Halictus similis Smith, 1853].

365. * Lasioglossum (Leuchalictus) zonulus (Smith, 1848). County records: Clallam³, Jefferson^1,2,3, King^3,81, Kitsap^7,134, Klickitat^1,2, Pierce^1,2,3,81, San Juan^1,2,3,6,124, Skagit^7,10,81, Spokane^1,2, Thurston¹³³, Walla Walla^1,2,7, Whatcom^6,81. Seasonality: May^1,2,6,133, Jun^1,2,7,133, Jul^1,2,6,7, Aug^1,2,3,6 (2020¹³³). Collections: BBSL, CUIC, JRYA, PWRC, WSDA, WSUC. Floral records: ASTEACEAE: Gaillardia aristata¹³³, Microseris laciniata¹³³; BRASSICACEAE: Lepidium campestre¹³³; LILIACEAE: Fritillaria affinis¹³³; ONAGRACEAE: Epilobium cilatum³; OROBANCHACEAE: Parentucellia viscosa¹³³; ROSACEAE: Potentilla gracilis¹³³

366. Lasioglossum (Sphecodogastra) aberrans (Crawford, 1903). County records: Adams⁵⁷, Spokane^1,2. Seasonality: Jun^1,2 (2015^1,2). Collections: BBSL

367. † Lasioglossum (Sphecodogastra) allonotus (Cockerell, 1936). County records: Chelan⁷, Yakima⁷. Seasonality: Apr⁷, May⁷, Jun⁷, Sep⁷ (2008⁷). Collections: WSUC

368. Lasioglossum (Sphecodogastra) comagenense (Knerer and Atwood, 1964). County records: Pierce^1,2,4,80, Thurston^1,2,4,80, Yakima^1,2. Seasonality: Apr^1,2,4, Jun^1,2,4, Jul^1,2 (2009^1,2,4). Collections: INHS, PCYU

369. Lasioglossum (Sphecodogastra) cooleyi (Crawford, 1906). County records: Jefferson^1,2, Klickitat^1,2, Okanogan^1,2,3,59, San Juan^1,2,124, Skagit³, Spokane^1,2, Stevens^1,2, Walla Walla^1,2, Whitman⁶¹. Seasonality: Apr^1,2,61, May^1,2, Jun^1,2, Jul^1,2,3, Aug^1,2,3, Sep^1,2 (2015^1,2). Collections: BBSL, PWRC, UCMS. Floral records: ROSACEAE: Potentilla gracilis³

370. † Lasioglossum (Sphecodogastra) cordleyi (Crawford, 1906). County records: Clark⁷. Seasonality: Jul⁷, Aug⁷ (1970⁷). Collections: WSUC

371. Lasioglossum (Sphecodogastra) lusorium (Cresson, 1872). County records: Benton^57,80, Grant⁷, Walla Walla^1,2, Yakima⁵⁷. Seasonality: May^1,2, Jun^1,2,7, Jul^1,2, Aug^1,2 (2012^1,2). Collections: BBSL, WSUC. Comments: McGinley (2003) records this species on the Yakima River at Morgan’s Ferry and places the location in Kittitas County; however, a review of historical maps indicates Morgan’s Ferry is located in Yakima County.

372. † Lasioglossum (Sphecodogastra) occultum (Vachal, 1904). [= Halictus occultus Vachal, 1904]. County records: Skagit^1,2, Thurston^1,2,4. Seasonality: Jun^1,2,4, Aug^1,2 (2011^1,2). Collections: PWRC

373. † Lasioglossum (Sphecodogastra) orthocarpi (Cockerell, 1936). County records: Island⁷, San Juan^1,2,124. Seasonality: May^1,2, Jul^1,2, Aug^1,2,7 (2011^1,2,124). Collections: PWRC, WSUC

Genus Sphecodes Latreille

374. Sphecodes arvensiformis Cockerell, 1904. County records: Cowlitz^1,2,3, Thurston¹¹⁷, Walla Walla^1,2,3. Seasonality: Jun^1,2,3,117, Jul^1,2,3 (1979^1,2,3). Collections: BBSL

375. ‡ Sphecodes columbiae Cockerell, 1906. County records: Grant^1,2,3,121. Seasonality: Jul^1,2,3,121 (1902^1,2,3,121). Collections: NMNH. Holotype. USA, Washington, Grant County, Grand Coulee; 12 July 1902; Type No. 29398, USNM ENT 00535232

376. ‡ Sphecodes hesperellus Cockerell, 1904. County records: Thurston¹¹⁷. Seasonality: Jun¹¹⁷ (1895¹¹⁷)

377. ‡ Sphecodes kincaidii Cockerell, 1898. County records: Thurston^1,2,3,117. Seasonality: Jun^1,2,3,117 (1895^1,2,3). Collections: NMNH. Holotype. USA, Washington, Thurston County, Olympia; 19 June 1895; Type No. 18975, USNM ENT 00535248

378. ‡ Sphecodes manni Cockerell, 1913. County records: Whitman^1,2,3,127. Seasonality: Sep^1,2,3,127 (1908^1,2,3,127). Collections: NMNH. Holotype. USA, Washington, Whitman County, Wawawai; 6 September 1908; WM Mann; Type No. 23322, USNM ENT 535259.

379. ‡ Sphecodes minor Robertson, 1898. County records: Thurston¹¹⁷. Seasonality: Jun¹¹⁷ (1896¹¹⁷)

380. ‡ Sphecodes olympicus Cockerell, 1904. County records: Pacific^1,2, Thurston¹¹⁷. Seasonality: May¹¹⁷, Aug^1,2 (1952^1,2). Collections: EMEC. Comments: Discover Life has synonymized S. olympicus with S. confertus without reference or explanation. We are not aware of any published work that that synonymizes these species and retain them as separate taxa in this checklist.

381. ‡ Sphecodes washingtoni Cockerell, 1904. County records: Thurston¹¹⁷. Seasonality: Jun¹¹⁷ (1895¹¹⁷)

Nomiinae: Nominiini

Genus Nomia Latreille

382. Nomia (Acunomia) melanderi Cockerell, 1906. County records: Benton^1,2, Walla Walla^1,2,3,78, Whitman^1,2,3, Yakima¹²¹. Seasonality: Jun^1,2, Jul^1,2,121, Nov¹ (2022^1,2). Collections: AMNH, iNaturalist, NMNH, SEMC. Conservation status: G5 – Secure globally (NatureServe 2024)

Rophitinae

Genus Dufourea Lepeletier

383. †‡ Dufourea calochorti (Cockerell, 1924). County records: Yakima^1,2,3. Seasonality: Jul^1,2,3 (1925^1,2,3). Collections: BBSL

384. Dufourea campanulae (Cockerell, 1897). County records: Clallam^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Pierce^1,2,3, Thurston^1,2,118,133. Seasonality: Jun^1,2,118,133, Jul^1,2,3, Aug^1,2,3 (2018¹³³). Collections: BBSL, EMEC, JRYA, SEMC. [= Halictoides campanulae Cockerell, 1897]. Floral records: CAMPANULACEAE: Campanula rotundifolia¹³³, C. scouleri¹¹⁸

385. † Dufourea holocyanea (Cockerell, 1925). County records: Asotin^1,2,3, Kittitas^1,2,3, Klickitat^2,3, Stevens^2,3, Yakima^1,2,3. Seasonality: May^1,2,3, Jun^2,3, Jul^1,2,3 (2000^1,2,3). Collections: BBSL, SEMC

386. Dufourea maura (Cresson, 1878). County records: Clallam³, Okanogan^1,2,3,4,59, Spokane^1,2. Seasonality: Jun^1,2,3,4, Jul^1,2, Aug³ (2015^1,2). Collections: BBSL, JRYA. Floral records: ASTERACEAE: Achillea millefolium^3,59

387. Dufourea trochantera Bohart, 1948. County records: Clallam^1,2,3,82, Okanogan^1,2,3,59, Yakima^1,2,3. Seasonality: May^1,2, Jul^1,2,3, Aug^1,2,3,82 (2007^1,2). Collections: BBSL, SEMC. Floral records: HYDROPHYLLACEAE: Phacelia⁸², P. leptosepala^3,59

Megachilidae: Megachilinae: Anthidiini

Genus Anthidiellum Cockerell

388. † Anthidiellum (Loyolanthidium) notatum (Latreille, 1809). County records: Lincoln², Spokane². Seasonality: Jun², Aug² (2015²). Collections: BugGuide

389. † Anthidiellum (Loyolanthidium) robertsoni (Cockerell, 1904). County records: Benton^1,2, Chelan^1,2,3, Klickitat^1,2,3. Seasonality: Jul^1,2,3, Aug^1,2 (2022^1,2). Collections: BBSL. [= Anthidiellum notatum robertsoni (Cockerell, 1904)]

Genus Anthidium Fabricius

390. † Anthidium (Anthidium) atrifrons Cresson, 1868. County records: Asotin³, Columbia¹³⁵, Whitman³, Yakima³. Seasonality: May³, Jun¹³⁵, Jul³ (2021¹³⁵). Collections: AMNH, BBSL, NMDG, SEMC. Conservation status: G5 – Secure Globally (NatureServe 2024)

391. †§ Anthidium (Anthidium) banningense Cockerell, 1904. County records: Benton⁷, Garfield¹³⁵. Seasonality: May^7,135 (2023¹³⁵). Collections: NMDG, WSUC. Conservation status: G3 – Vulnerable globally (NatureServe 2024). Floral records: HYDROPHYLLACEAE: Phacelia heterophylla¹³⁵

392. † Anthidium (Anthidium) clypeodentatum Swenk, 1914. County records: Benton^1,2, Spokane^1,2. Seasonality: May^1,2, Jun^1,2 (2015^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure Globally (NatureServe 2024)

393. § Anthidium (Anthidium) edwardsii Cresson, 1878. County records: Grant^41,91. Collections: NMNH. [= Anthidium depressum H. F. Schwarz, 1927]. Holotype. USA, Washington, Grant County, Coulee City; USNM 40164. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

394. Anthidium (Anthidium) emarginatum (Say, 1824). County records: Adams^1,2,3, Benton^1,2, Jefferson^1,2, Lincoln³, Whitman⁸. Seasonality: Apr^1,2, May^1,2, Jun^1,2,3, Aug^1,2 (2015^1,2). Collections: BBSL, FMNH, UCRC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: HYDROPHYLLACEAE: Phacelia heterophylla⁸

395. †‡ Anthidium (Anthidium) formosum Cresson, 1878. County records: Spokane^1,3. Seasonality: Jul^1,3 (1882^1,3). Collections: INHS. Conservation status: G4 – Apparently Secure Globally (NatureServe 2024)

396. †* Anthidium (Anthidium) manicatum (Linnaeus, 1758). County records: Benton^1,2, Chelan^1,2,3, Clallam^1,2,3, Clark^1,2,3, Douglas^1,2,3, Grant^1,2,3, Jefferson^1,2,3, King^1,2,3, Kittitas^1,2, Lewis^1,2,3, San Juan^1,2,5,6, Skamania^1,2, Snohomish^1,2,6, Spokane^1,2,3, Thurston^1,2,3,6, Walla Walla^1,2, Whatcom^1,2,3, Yakima^1,2,3. Seasonality: May^1,2, Jun^1,2,3, Jul^1,2,3,5,6, Aug^1,2,3,6, Sep^1,2,3 (2022^1,2). Collections: AMNH, BugGuide, iNaturalist, WSDA. Conservation status: G5 – Secure globally (NatureServe 2024)

397. Anthidium (Anthidium) mormonum Cresson, 1878. County records: Kittitas^1,2,3, Klickitat^1,2, Okanogan^1,2,59, Spokane^1,2. Seasonality: May^1,2, Jun^1,2, Jul^1,2,3, Aug^1,2 (2015^1,2). Collections: BBSL, INHS, SEMC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Erigeron nivalis⁵⁹; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹

398. Anthidium (Anthidium) tenuiflorae Cockerell, 1907. County records: Kittitas^1,2,3, Okanogan^1,2,4,59, San Juan^{1,2,3,5,6,124}, Skagit³. Seasonality: Jun⁵, Jul^1,2,5,6, Aug^1,2,3,4 (2017⁶). Collections: BBSL, JRYA, PWRC, SEMC, WSDA. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: CRASSULACEAE: Sedum lanceolatum⁵⁹; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; LAMIACEAE: Micromeria douglasii⁵; ROSACEAE: Rubus ulmifolius⁵

399. Anthidium (Anthidium) utahense Swenk, 1914. County records: Grant^1,3, Klickitat^1,2, Spokane^1,2, Walla Walla^1,2,3, Whitman^8,41,91,98, Yakima^1,2,3. Seasonality: Jun^1,2, Jul^1,2,3, Aug^1,2 (2015^1,2). Collections: AMNH, BBSL, INHS, NMNH, SEMC, WSUC. [= Anthidium sagittipictum Swenk, 1914]. Holotype. USA, Washington, Whitman County, Pullman. Conservation status: G5 – Secure globally (NatureServe 2024). Floral Records: FABACEAE: Vicia villosa⁸

400. †* Anthidium (Proanthidium) oblongatum (Illiger, 1806). County records: Clark^1,2, King^1,2,3, Pierce^1,2, Snohomish^1,2, Spokane^1,2. Seasonality: May^1,2, Jun^1,2, Jul^1,2,3, Aug^1,2, Sep^1,2 (2022^1,2). Collections: BugGuide, iNaturalist. Conservation status: G5 – Secure globally (NatureServe 2024)

Genus Dianthidium Cockerell

401. Dianthidium (Dianthidium) curvatum (Smith, 1854). County records: Garfield^1,2,3. Seasonality: Jul^1,2 (1998^1,2). Collections: BBSL. Floral records: ASTERACEAE: Carthamus tinctorius³

401a. † Dianthidium (Dianthidium) curvatum sayi Cockerell, 1907. County records: Benton^1,2,3, Garfield^1,2,3, Whitman^1,2,3. Seasonality: Jul^1,2,3, Aug^1,2, Sep^2,3 (2021^1,2). Collections: BBSL, iNaturalist, INHS

402. Dianthidium (Dianthidium) heterulkei Schwarz, 1940. County records: Okanogan^1,2,3,59. Seasonality: Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL. Floral records: ASTERACEAE: Erigeron speciosus^3,59

403. Dianthidium (Dianthidium) parvum (Cresson, 1878). County records: Thurston¹³³. Seasonality: Jul¹³³ (2018¹³³). Floral records: ASTERACEAE: Crepis capillaris¹³³, Erigeron speciosus¹³³, Hieracium scouleri¹³³, Solidago missouriensis¹³³

404. † Dianthidium (Dianthidium) plenum Timberlake, 1943. County records: Klickitat^1,2,3. Seasonality: Jul^1,2,3 (2010^1,2,3). Collections: BBSL

405. Dianthidium (Dianthidium) pudicum (Cresson, 1879). County records: Benton^1,2,3,71, Spokane⁷, Walla Walla^1,2. Seasonality: Apr^1,2, May^1,2, Jun^1,2, Jul^1,2, Aug^1,2,3,7, Sep^1,2 (2023⁷). Collections: BBSL

406. Dianthidium (Dianthidium) subparvum Swenk, 1914. County records: Chelan^1,2,3, Okanogan^1,2,3,59, Spokane^1,2, Thurston¹³³, Walla Walla^1,2,3,71, Whitman⁹¹. Seasonality: Jul^1,2,3,133, Aug^1,2,3, Sep^1,2,3 (2019¹³³). Collections: BBSL. Holotype. USA, Washington, Whitman County, Pullman. Floral records: ASTERACEAE: Crepis capillaris¹³³, Erigeron speciosus¹³³

407. Dianthidium (Dianthidium) ulkei (Cresson, 1878). County records: Klickitat^1,2, Okanogan^1,2,3,59, Pierce⁹¹, Spokane^1,2. Seasonality: Jul^1,2, Aug^1,2,3, Sep^1,2 (2014^1,2). Collections: BBSL, CAS. [= Dianthidium ulkei reductum Timberlake, 1943]. Holotype. USA, Washington, Pierce County, Longmire, Mt. Rainier National Park.

Genus Stelis Panzer

408. † Stelis (Dolichostelis) laticincta Cresson, 1878. County records: Benton^1,2, Clark^1,2, Douglas^1,2, Klickitat^1,2. Seasonality: Jul^1,2, Aug^1,2 (2022^1,2). Collections: BugGuide, iNaturalist

409. † Stelis (Stelis) calliphorina (Cockerell, 1911). County records: Spokane^1,2, Whitman^2,3. Seasonality: May^2,3, Jul^1,2 (2014^1,2). Collections: BBSL

410. † Stelis (Stelis) callura Cockerell, 1925. County records: Adams^1,2,3, Benton^1,2,3, Spokane^1,2, Whitman^2,3. Seasonality: May^1,2,3, Jun^2,3 (2016^1,2). Collections: BBSL

411. †‡ Stelis (Stelis) foederalis Smith, 1854. County records: Spokane^1,2,3. Seasonality: Jul^1,2,3 (1963^1,2,3). Collections: BBSL

412. † Stelis (Stelis) holocyanea (Cockerell, 1925). County records: Spokane^1,2. Seasonality: May^1,2, Jul^1,2,3 (2015^1,2). Collections: BBSL

413. † Stelis (Stelis) lateralis Cresson, 1864. County records: Spokane^1,2, Walla Walla^1,2,3. Seasonality: May^1,2,3, Jun^1,2 (2015^1,2). Collections: BBSL

414. Stelis (Stelis) montana Cresson, 1864. County records: Benton^1,2,3, Chelan^1,2,3, Kittitas^1,2,3, Okanogan^1,2,3,59, Stevens³, Thurston^1,2,3, Walla Walla³, Yakima^1,2,3. Seasonality: May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL, SEMC. Floral records: ASTERACEAE: Erigeron speciosus^3,59; FABACEAE: Lupinus sericeus^3,59

415. † Stelis (Stelis) monticola Cresson, 1878. County records: King^1,2,3, San Juan^1,2,3, Spokane^1,2. Seasonality: Apr^1,2, May^1,2,3, Jul³ (2015^1,2). Collections: AMNH, BBSL

416. †‡ Stelis (Stelis) nitida Cresson, 1878. County records: King^1,2,3. Seasonality: May^1,2, Jun^1,2,3 (1928^1,2,3). Collections: BBSL. Floral records: ASTERACEAE: Hypochaeris³

417. †‡ Stelis (Stelis) occidentalis Parker and Griswold, 2013. County records: Spokane^1,2,3. Seasonality: Jun^1,2,3 (1969^1,2,3). Collections: BBSL

418. † Stelis (Stelis) pavonina (Cockerell, 1908). County records: Lincoln^2,3, Spokane^1,2. Seasonality: May^1,2,3, Jun^1,2, Jul^1,2 (2015^1,2). Collections: BBSL

419. ‡ Stelis (Stelis) rubi Cockerell, 1898. County records: King^1,2,98, Thurston⁹⁸. Seasonality: May^1,2,98, Jun⁹⁸ (1897^1,2). Collections: NMNH. Holotype. USA, Washington, King County, Seattle; 11 May 1897; 18979 USNM, USNM ENT 00537080. Floral records: ROSACEAE: Rubus ursinus⁹⁸. Comments: Discover Life has synonymized S. rubi with S. monticola without reference or explanation. We are not aware of any published work that that synonymizes these species and retain them as separate taxa in this checklist.

420. Stelis (Stelis) subcaerulea Cresson, 1878. County records: Okanogan^1,2,3,59, Whitman⁸. Seasonality: Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL, WSUC. Floral records: ASTERACEAE: Achillea millefolium⁸, Eriophyllum lanatum⁸; CRASSULACEAE: Sedum lanceolatum^3,59

421. Stelis (Stelis) subemarginata Cresson, 1878. County records: Benton^1,2,3, Okanogan^1,2,3,59, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,2,3. Seasonality: May^1,2,3, Jun^1,2,3, Aug^1,2,3 (2015^1,2). Collections: BBSL. Floral records: ASTERACEAE: Anaphalis margaritacea^3,59, Erigeron corymbosus^3,59

422. † Stelis subglauca (Cockerell, 1925). County records: Spokane^1,2. Seasonality: Jul^1,2 (2011^1,2). Collections: BBSL. Comments: Discover Life has synonymized S. subglauca with S. foederalis without reference or explanation. We are not aware of any published work that that synonymizes these species and retain them as separate taxa in this checklist.

Dioxyini

Genus Dioxys Lepeletier and Serville

423. † Dioxys aurifuscus (Titus, 1901). County records: Grant¹. Seasonality: Jun¹ (2022¹). Collections: iNaturalist

424. † Dioxys pacificus Cockerell, 1916. County records: Benton^1,2. Seasonality: May^1,2 (2014^1,2). Collections: BBSL

425. † Dioxys pomonae Cockerell, 1910. County records: Pierce³, Spokane^1,2. Seasonality: Jun^1,2,3 (2014^1,2). Collections: BBSL

426. † Dioxys productus (Cresson, 1879). County records: Spokane^1,2. Seasonality: Jul^1,2 (2015^1,2). Collections: BBSL

Megachilini

Genus Coelioxys Latreille

427. Coelioxys (Boreocoelioxys) moestus Cresson, 1864. County records: Okanogan^1,2,59, Thurston^1,2. Seasonality: Jun^1,2, Aug^1,2 (2004^1,2,59). Collections: BBSL, UCMC. Floral records: ASTERACEAE: Erigeron speciosus⁵⁹

428. Coelioxys (Boreocoelioxys) octodentatus Say, 1824. County records: Kittitas^1,2, Walla Walla^1,2,71, Yakima^1,2. Seasonality: Jun^1,2, Jul^1,2, Sep^1,2 (2012^1,2). Collections: AMNH, BBSL, MCZ, SEMC

429. Coelioxys (Boreocoelioxys) rufitarsis Smith, 1854. County records: Benton^1,2,3,71, Chelan³, Clallam³, Ferry^1,2, Franklin³, Jefferson^1,2, King^1,2, Kittitas^2,3, Lewis^1,2,4, Okanogan^1,2, San Juan^{1,2,3,5,22,124,136}, Thurston¹³³, Walla Walla^1,2,3,71, Whitman^1,2,3, Yakima^1,2,3. Seasonality: May^1,2,3, Jun^1,2,3,133, Jul^1,2,3,5,133, Aug^1,2,3, Sep^1,2,3 (2021^1,2). Collections: AMNH, BBSL, CUIC, FMNH, iNaturalist, JRYA, PCYU, PWRC, RUAC, SEMC. Host records: Megachile perihirta Cockerell¹³⁴. Floral records: APOCYNACEAE: Apocynum androsaemifolium¹³³; ASTERACEAE: Crepis capillaris^133,136, Hypochaeris radicata⁵, Leucanthemum vulgare¹³³, Microseris laciniata¹³³; ONAGRACEAE: Clarkia amoena¹³³

430. Coelioxys (Coelioxys) sodalis Cresson, 1878. County records: Clallam³, Okanogan^1,2,3,59, Thurston^52,133. Seasonality: Jun^52,133, Aug^1,2,3 (2018¹³³). Collections: AMNH, BBSL, JRYA. Holotype. USA, Washington, Thurston County, Olympia; 9–24 June 1895, 26 June 1896; T Kincaid. Floral records: ASTERACEAE: Agoseris glauca var. dasycephala^3,59, Eriophyllum lanatum¹³³, Leucanthemum vulgare¹³³

431. † Coelioxys (Xerocoelioxys) edita Cresson, 1872. County records: Asotin^1,2,4. Seasonality: May^1,2,4 (2007^1,2,4). Collections: PCYU

432. Coelioxys (Xerocoelioxys) grindeliae Cockerell, 1900. County records: Benton^1,2,3,71. Seasonality: Aug^1,2,3 (1997^1,2,3). Collections: BBSL

433. † Coelioxys (Xerocoelioxys) mesae Cockerell, 1921. County records: Grant^1,2,4. Collections: PCYU

434. Coelioxys (Xerocoelioxys) serricaudatus J. R. Baker, 1975. County records: Spokane⁷, Whitman^58,90. Seasonality: May⁷, Jun^58,90 (2024⁷). Paratype. USA, Washington, Whitman County, Palouse; 26 June 1961; RW Dawson.

Genus Megachile Latreille

435. Megachile (Argyropile) parallela Smith, 1853. County records: Asotin^1,2, Benton^1,2,3, Walla Walla^1,2,3,25, Whitman^2,3,8,25,71, Yakima²⁵. Seasonality: Jun^1,2,3,25, Jul^2,3, Aug^1,2,3, Sep^1,2,3 (2015^1,2). Collections: BBSL, iNaturalist, INHS, TAMU, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Helianthus annuus⁸

436. Megachile (Chelostomoides) angelarum Cockerell, 1902. County records: Benton^1,2,3, Chelan^1,2, King^1,2, Thurston⁶, Walla Walla^1,2,3,26, Whitman^1,2. Seasonality: Jun^1,2,3,26, Jul^1,2, Aug^1,2,6 (2020^1,2). Collections: BBSL, iNaturalist, TAMU, WSDA. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Rhaponticum repens³

437. * Megachile (Eutricharaea) apicalis Spinola, 1808. County records: Benton^1,2,3, Columbia^1,2,4, Kittitas^1,2, Spokane^1,2,3, Walla Walla^1,2,3,71, Whitman^2,3. Seasonality: Jun^1,2,3, Jul^1,2, Aug^1,2,3, Sep^1,2 (2021^1,2). Collections: BBSL, iNaturalist, PCYU. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Rhaponticum repens³

438. †*‡ Megachile (Eutricharaea) concinna Smith, 1879. County records: Yakima^1,2,3. Seasonality: Feb^1,2,3 (1969^1,2,3). Collections: BBSL

439. * Megachile (Eutricharaea) rotundata (Fabricius, 1787). County records: Benton^1,2,3,128, Chelan^1,2,3, King^1,2, Spokane^1,2,3, Walla Walla^1,2,3, Yakima^2,128. Seasonality: Feb², Jun^1,2,3, Jul^1,2,3 (2020^1,2). Collections: BBSL, BugGuide, iNaturalist, TAMU. Conservation status: G5 – Secure globally (NatureServe 2024)

440. Megachile (Litomegachile) brevis Say, 1837. County records: Benton⁷¹, Garfield⁴⁶, Skamania^1,2, Spokane^1,2,3, Thurston¹³³, Walla Walla⁷¹, Whitman⁸, Yakima^1,2,27. Seasonality: Jun^1,2,46,133, Jul^1,2,3,133 (2020¹³³). Collections: BBSL, BugGuide, MSU, MCZ, UCRC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: APOCYNACEAE: Apocynum androsaemifolium¹³³; ASTERACEAE: Gaillardia aristata¹³³, Helianthus annuus⁸, Solidago missouriensis¹³³; HYPERICACEAE: Hypericum perforatum¹³³; ONAGRACEAE: Clarkia amoena¹³³

441. Megachile (Litomegachile) cleomis Cockerell, 1900. County records: Grant⁷, Whitman⁷, Yakima^7. Seasonality: May⁷, Jul⁷, Sep⁷ (1900⁷). Collections: WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Comments: Records from Grant and Yakima counties during May and September were males identified by Mitchell. Megachile cleomis was raised to full species from a subspecies of M. texana based on DNA barcodes with no morphological diagnosis (Sheffield and Genaro 2013). Mitchell (1935b) indicates that males of M. cleomis and M. lippiae are indistinguishable. As there is no way to confirm the identification of these males, it is possible they may represent records of M. lippiae.

441a. Megachile (Litomegachile) cleomis Cockerell, 1900/lippiae Cockerell, 1900. County records: Chelan^1,2, Garfield⁴⁶, Walla Walla^1,2,3, Whatcom^1,2,3, Whitman^1,2,3. Seasonality: May^1,2, Jun^1,2, Jul^1,2,3 (1995^1,2). Collections: BBSL, SEMC, TAMU. Floral records: FABACEAE: Lupinus sericeus³. Comments: These records were originally identified as M. texana. Sheffield et al. (2011) and Sheffield and Genaro (2013) raised M. lippiae and M. cleomis, respectively, to full species from subspecies of M. texana, which has a distinctly eastern distribution compared to M. cleomis. While Sheffield and Genaro (2013) don’t describe where the east/west dividing line is located, it is highly likely that Washington is far enough west for these records to not be M. texana. Since these specimens have not been physically examined, it is unclear whether these records are actually M. lippiae or M. cleomis.

442. Megachile (Litomegachile) coquilletti Cockerell, 1915. County records: Benton^1,2,3, Chelan^1,2,3, Walla Walla^1,2,3, Whitman²⁷, Yakima²⁷. Seasonality: Jul^1,2,3 (1998^1,2). Collections: BBSL, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

443. Megachile (Litomegachile) mendica Cresson, 1878. County records: Kittitas^1,3, Whitman^2,3. Seasonality: Jun^1,2,3 (2003^2,3). Collections: AMNH, BBSL. Conservation status: G5 – Secure globally (NatureServe 2024)

444. Megachile (Litomegachile) onobrychidis Cockerell, 1908. County records: Benton^1,2,3, Clark^1,2, Ferry^1,2,3, Garfield^1,2,3,46, Grant^1,2,3, Klickitat^1,2, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,3,6,27, Yakima^1,2,3. Seasonality: May^1,2, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3,6, Sep^1,2, Oct^1,2 (2014^1,2). Collections: AMNH, BBSL, SEMC, WSDA. [= Megachile brevis onobrychidis Cockerell, 1908]. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Rhaponticum repens³

445. § Megachile (Litomegachile) snowi Mitchell, 1927. County records: Whitman³². Seasonality: Jul³² (2013³²). Conservation status: G3 – Vulnerable globally (NatureServe 2024)

446. Megachile (Megachile) centuncularis (Linnaeus, 1758). County records: Okanogan^1,2,3,59, Pierce²⁴, Whitman²⁴. Seasonality: Jul²⁴, Aug^1,2,3 (2012^1,2). Collections: BBSL. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Erigeron speciosus^3,59

447. ‡ Megachile (Megachile) lapponica Thomson, 1872. County Records: Pend Oreille⁹⁴. Seasonality: Jul⁹⁴ (1931⁹⁴). [= Megachile nivalis Friese, 1903]. Conservation status: G5 – Secure globally (NatureServe 2024)

448. Megachile (Megachile) montivaga Cresson, 1878. County records: Benton^1,2,3,71, Grant^1,2, Kittitas^1,2, Klickitat^1,2, Okanogan^1,2,3,59, Pierce^1,2,3,24, Spokane^1,2, Thurston²⁴, Wahkiakum^1,2, Walla Walla^1,2,3,71, Whitman^2,3,24, Yakima²⁴. Seasonality: May^1,2, Jun^1,2,3,24, Jul^1,2,3,24, Aug^1,2,3 (2020^1,2). Collections: BBSL, iNaturalist, INHS, SEMC, TAMU. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Cirsium vulgare^3,59

449. Megachile (Megachile) relativa Cresson, 1878. County records: Chelan³, Clallam^1,2,3, Clark^1,2,3, Jefferson^2,3, King²⁴, Mason³, Okanogan^1,2,3,59, Pierce^1,2,3,24, Thurston²⁴, Whitman^1,2,3,24, Yakima^1,2,3. Seasonality: Jun^1,2,3,24, Jul^1,2,3,24, Aug^1,2,3 (2014³). Collections: AMNH, BBSL, INHS, JRYA, SEMC, UCRC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Achillea millefolium⁵⁹, Erigeron speciosus^3,59, Taraxacum officinale^3,59; BRASSICACEAE: Smelowskia calycina⁵⁹; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium^3,59

450. § Megachile (Megachiloides) anograe Cockerell, 1908. County records: Asotin¹³¹, Benton^1,2, Grant^1,2,4. Seasonality: May^1,2,131 (2015^1,2). Collections: BBSL, PCYU. [= Megachile laurita Mitchell, 1927]. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

451. Megachile (Megachiloides) gravita Mitchell, 1933. County records: Klickitat^1,2, Thurston⁹⁹. Seasonality: Jul^1,2, Aug⁹⁹ (2011^1,2). Collections: BBSL. [= Megachile astata Mitchell, 1933]. Paratype. USA, Washington, Thurston County, Olympia; 20 August 1893; T Kincaid. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

452. §‡ Megachile (Megachiloides) legalis Cresson, 1879. County records: Grant^131,132. Seasonality: Jun^131,132 (1902^131,132). Collections: WSUC. [= Megachile (Xeromegachile) couleeana Mitchell, 1938]. Holotype. USA, Washington, Grant County, Grand Coulee, Wash Soap Lake; 29 June 1902; WSU No. 425. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

453. § Megachile (Megachiloides) nevadensis Cresson, 1879. County records: Benton^1,2,3, Yakima¹³¹. Seasonality: Aug^1,2,3, Sep^1,2,3 (1995^1,2,3). Collections: BBSL. Conservation status: G3 – Vulnerable globally (NatureServe 2024). Floral records: ASTERACEAE: Senecio³

454. Megachile (Megachiloides) pascoensis Mitchell, 1934. County records: Franklin^1,2,3,99, Spokane^1,2, Thurston¹³³, Whitman⁹⁹. Seasonality: May^1,2,3,99, Jun¹³³, Jul^99,133 (2020¹³³). Collections: BBSL, NMNH. Holotype. USA, Washington, Franklin County, Pasco; 25 May 1896; USNM No. 39982. Paratype. USA, Washington, Whitman County Pullman; July. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ONAGRACEAE: Clarkia amoena¹³³; POLEMONIACEAE: Gilia capitata¹³³

455. Megachile (Megachiloides) subnigra Cresson, 1879. County records: Adams^30,131, Benton^1,2, Grant^1,2,4,131, Whitman¹³¹, Yakima^1,2,3,30,92. Seasonality: May^1,2,4,131, Jun¹³¹, Jul^1,2,3,92 (2015^1,2). Collections: BBSL, RSKM, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

456. § Megachile (Megachiloides) umatillensis (Mitchell, 1927). County records: Benton^{1,2,3,6,29,95}, Spokane^29,95, Walla Walla^1,2. Seasonality: May^1,2,6, Jun^1,2,29,95, Jul^1,2,3,29,95, Aug^1,2 (2022⁶). Collections: BBSL, WSDA. Paratype. USA, Washington Territory, Little Spokane; 26 July 1882; S Henshaw. [= Megachiloides umatillensis Mitchell, 1927]. Holotype. USA, Washington Territory, Camp Umatilla; 26 June 1882; MCZ Type No 15714. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

457. ‡ Megachile (Megachiloides) wheeleri Mitchell, 1927. County records: Benton⁹⁵, Spokane^1,2,93,95, Yakima¹³¹. Seasonality: Jun⁹⁵, Jul^1,2,131 (1936¹³¹). Collections: MCZ. [= Megachile spokanensis Mitchell, 1927]. Holotype. USA, Washington Territory, Little Spokane. Paratype. USA, Washington Territory, Camp Umatilla; 26 June 1882. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

458. Megachile (Sayapis) fidelis Cresson, 1878. County records: Benton^1,2,3, Chelan^1,2,3, Ferry^1,2,3, King^1,2, Kitsap^1,2, Kittitas^1,2, Okanogan^1,2,3,59, Thurston^1,2,3. Seasonality: Jun^1,2,3, Aug^1,2,3, Sep^1,2 (2022^1,2). Collections: BBSL, iNaturalist, SEMC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: BRASSICACEAE: Sisymbrium altissimum^3,59

459. Megachile (Sayapis) mellitarsis Cresson, 1878. County records: Grant^1,2, Yakima²⁸. Seasonality: May^1,2, Jul²⁸ (2007^1,2). Collections: PCYU. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

460. Megachile (Sayapis) pugnata Say, 1837. County records: Chelan^1,2,3, Ferry², King³, Kitsap^1,2,3, Okanogan^1,2,3,59, San Juan^3,28, Spokane², Thurston², Walla Walla^1,2,3,71, Whitman^2,8, Yakima²⁸. Seasonality: Jun^1,2,3, Jul^1,2,3, Aug^1,2,3, Sep^1,2,3 (2021^1,2). Collections: AMNH, BBSL, BugGuide, iNaturalist, UCRC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Achillea millefolium³, Erigeron speciosus^3,8, Taraxacum officinale³

461. § Megachile (Xanthosarus) dentitarsus Sladen, 1919. County records: San Juan^1,2,3,124, Yakima^1,2,29. Seasonality: Jul^1,2,29 (2011^1,2,124). Collections: MCZ, PWRC. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

462. † Megachile (Xanthosarus) frigida Smith, 1853. County records: Grays Harbor^1,2,3, King³, Lewis^2,3, Okanogan^1,2,3, Thurston^2,3, Walla Walla^1,2,3, Yakima^1,2,3. Seasonality: Jun^1,2,3, Jul^1,2,3, Aug³ (2017²). Collections: BBSL, BugGuide, SEMC, UCRC. Conservation status: G5 – Secure globally (NatureServe 2024)

463. Megachile (Xanthosarus) gemula Cresson, 1878. County records: Okanogan^1,2,3,59, San Juan², Thurston^3,24,133. Seasonality: May¹³³, Jun^1,2,3,24,133, Jul^1,2,3,24 (2020¹³³). Collections: BBSL, SEMC, UCRC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASPARAGACEAE: Triteleia hyacinthina¹³³; CAMPANULACEAE: Campanula rotundifolia^3,59; CAPRIFOLIACEAE: Plectritis congesta¹³³; FABACEAE: Lupinus^3,59; HYDROPHYLLACEAE: Phacelia leptosepala^3,59; ROSACEAE: Physocarpus malvaceus⁸

463a. Megachile (Xanthosarus) gemula cressonii Dalla Torre, 1896. County records: Thurston²⁴. Seasonality: Jul²⁴ (1896²⁴)

463b. Megachile (Xanthosarus) gemula gemula Cresson, 1878. County records: Garfield⁴⁶. Seasonality: (1989⁴⁶)

464. Megachile (Xanthosarus) melanophaea Smith, 1853. County records: Chelan³, Clallam^1,2,3, Jefferson^1,2,3, King^1,2,3, Okanogan^1,2,3,59, Pierce^1,2,3,24, San Juan^{1,2,3,5,24,124,136}, Skamania^1,2,3, Thurston^2,24,133, Wahkiakum^1,2, Yakima^1,2,3. Seasonality: May^1,2,133, Jun^{1,2,3,5,24,133}, Jul^{1,2,3,5,24,32}, Aug^1,2,3,24 (2021^1,2). Collections: AMNH, BBSL, BugGuide, iNaturalist, JRYA, PWRC, SEMC, UCRC. [= Megachile gemula fulvogemula Mitchell, 1935]. Paratype. USA, Washington, Thurston County, Olympia; 2 June 1894. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: APOCYNACEAE: Apocynum androsaemifolium¹³³; ASTERACEAE: Eriophyllum lanatum¹³³, Hypochaeris radicata¹³³, Microseris laciniata¹³³; CAMPANULACEAE: Campanula rotundifolia^3,59,133; CAPRIFOLIACEAE: Plectritis congesta¹³³; CONVOLVULACEAE: Calystegia soldanella¹³⁶; FABACEAE: Lupinus albicaulis¹³³, L. littoralis¹³⁶, Trifolium repens^3,59, Vicia sativa^5,133; LAMIACEAE: Micromeria douglasii⁵; ONAGRACEAE: Chamerion angustifolium¹³³; PLANTAGINACEAE: Penstemon washingtonensis⁵⁹; PLUMBAGINACEAE: Armeria maritima¹³³; ROSACEAE: Potentilla gracilis¹³³, Rubus ulmifolius⁵

464a. Megachile (Xanthosarus) melanophaea calogaster Cockerell, 1898. County records: King²⁴, Thurston²⁴. Seasonality: Jun²⁴ (1895²⁴). Collections: NMNH, WSUC. Holotype. USA, Washington, Thurston County, Olympia; 21 June 1895; USNM No. 4268

465. Megachile (Xanthosarus) perihirta Cockerell, 1898. County records: Benton^1,2,3, Chelan^1,2,3, Clallam^1,2,3, Douglas^1,2, Ferry^1,2,3, Garfield⁴⁶, Grant^1,2,3,29, Island^1,2, Jefferson^1,2,3, King^1,2,3,29, Kitsap^1,2,3,134, Kittitas^1,2,3,29, Klickitat^1,2, Okanogan^1,2,3,59, Pierce^1,2,3, San Juan^{1,2,3,5,6,29,124,136}, Skamania^1,2, Snohomish^1,2,3, Spokane^1,2, Stevens³, Thurston^1,2,3,29,133, Wahkiakum^1,2, Walla Walla^1,2,3,71, Whatcom^1,2,3,6, Whitman^1,2,3,8,29, Yakima^1,2,3. Seasonality: Jan^1,2, May^1,2, Jun^1,2,3,133, Jul^1,2,3,5,133, Aug^1,2,3,6, Sep^1,2,3,29, Oct^1,2 (2021^1,2). Collections: AMNH, BBSL, BugGuide, FMNH, iNaturalist, INHS, JRYA, PWRC, SEMC, TAMU, UCRC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: APOCYNACEAE: Apocynum androsaemifolium¹³³; ASTERACEAE: Achillea millefolium⁵⁹, Cirsium arvense^8,133, C. vulgare⁸, Crepis capillaris^133,136, Erigeron speciosus^3,59,133, Gaillardia aristata^8,133, Grindelia integrifolia⁵, Helianthus³, Hieracium scouleri¹³³, Hypochaeris radicata¹³³, Leucanthemum vulgare¹³³, Senecio jacobaea¹³³, S. serra⁸, S. triangularis⁵⁹, Solidago⁸, S. canadensis¹³³, S. missouriensis¹³³, Taraxacum officinale⁵⁹, Xanthium⁸; BRASSICACEAE: Cakile maritima¹³⁶; CONVOLVULACEAE: Calystegia soldanella¹³⁶; FABACEAE: Lupinus⁵⁹, L. sericeus³, Vicia villosa⁸; HYPERICACEAE: Hypericum perforatum¹³³; ONAGRACEAE: Chamerion angustifolium¹³³, Clarkia amoena¹³³; ROSACEAE: Rubus ulmifolius⁵

Osmiini

Genus Ashmeadiella Cockerell

466. ‡ Ashmeadiella (Arogochila) foxiella Michener, 1939. County records: Yakima⁴⁴. Seasonality: May⁴⁴ (1903⁴⁴)

467. Ashmeadiella (Arogochila) timberlakei timberlakei Michener, 1936. Comments: Michener (1939) notes an observation of a single specimen from Washington but does not provide a locality within the state.

468. Ashmeadiella (Ashmeadiella) aridula Cockerell, 1910. County records: Spokane^1,2, Whitman⁴⁴, Yakima^2,3. Seasonality: Jul^1,2,3,44 (2015^1,2). Collections: BBSL, SEMC

469. ‡ Ashmeadiella (Ashmeadiella) bucconis denticulata (Cresson, 1878). County records: Chelan⁴⁴, Yakima⁴⁴. Seasonality: Jul⁴⁴ (1918⁴⁴)

470. Ashmeadiella (Ashmeadiella) cactorum (Cockerell, 1897). County records: King⁴⁴, Okanogan^1,2,3,59, Thurston⁹⁷. Seasonality: Jul^44,97, Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL. [= Ashmeadiella curriei curriei Titus, 1904]. Floral records: ASTERACEAE: Taraxacum officinale^3,59; HYDROPHYLLACEAE: Phacelia leptosepala^3,59

471. ‡ Ashmeadiella (Ashmeadiella) californica californica (Ashmead, 1897). County records: Grant⁴⁴, Whitman^1,2,3,44. Seasonality: Jul^1,2,3,44 (1925^1,2,3,44). Collections: SEMC

472. Ashmeadiella (Ashmeadiella) cubiceps (Cresson, 1879). County records: Okanogan^1,2,3,59. Seasonality: Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL. Floral records: ASTERACEAE: Erigeron speciosus^3,59, Hieracium scouleri^3,59

473. † Ashmeadiella (Ashmeadiella) meliloti (Cockerell, 1897). County records: Spokane^1,2. Seasonality: Jul^1,2 (2015^1,2). Collections: BBSL

Genus Atoposmia Cockerell

474. Atoposmia (Atoposmia) elongata (Michener, 1936). County records: Okanogan^1,2,3,4,59, Pierce⁹⁶. Seasonality: Jul^1,2,3,4 (2004^1,2,3,4,59). Collections: BBSL

475. Atoposmia (Hexosmia) copelandica (Cockerell, 1908). County records: Okanogan^1,2,3,59, Stevens^1,2. Seasonality: Jul^1,2, Aug^1,2,3 (2014^1,2). Collections: BBSL. Floral records: HYDROPHYLLACEAE: Phacelia leptosepala^3,59

Genus Chelostoma Latreille

476. Chelostoma (Neochelostoma) minutum Crawford, 1916. County records: Okanogan^1,2,3,59, Spokane^43,96. Seasonality: Jun^1,2,3, Jul⁴³, Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL. Floral records: CRASSULACEAE: Sedum lanceolatum^3,59

477. Chelostoma (Neochelostoma) phaceliae Michener, 1938. County records: Asotin⁹⁶, Benton^1,2,3, Walla Walla^43,96. Seasonality: May⁴³, Jun^1,2,3 (1994^1,2,3). Collections: BBSL

Genus Heriades Spinola

478. † Heriades (Neotrypetes) carinata Cresson, 1864. County records: Cowlitz^1,2, King^1,2,3, Thurston³, Yakima^1,2. Seasonality: Jul^1,2, Aug^1,2,3 (1983^1,2,3). Collections: BBSL, SEMC, UCRC

479. Heriades (Neotrypetes) cressoni Michener, 1938. County records: Chelan^1,2,3, Okanogan^1,2,3,59. Seasonality: Jul^1,2,3, Aug^1,2,3 (2004^1,2,3,59). Collections: BBSL. Floral records: ASTERACEAE: Erigeron speciosus^3,59; MALVACEAE: Iliamna longisepala³

480. †‡ Heriades (Neotrypetes) occidentalis Michener, 1938. County records: Yakima³. Seasonality: Jul³ (1920³). Collections: UCRC

481. Heriades (Neotrypetes) variolosa (Cresson, 1872). County records: Stevens^1,2, Yakima^1,2,3,42. Seasonality: Jul^1,2,3, Aug^1,2,3 (2011^1,2). Collections: BBSL, SEMC

Genus Hoplitis Klug

482. Hoplitis (Alcidamea) albifrons (Kirby, 1837). County records: Chelan³, Clallam^1,2,3, Columbia^1,2,3, Kittitas^1,2, Klickitat^1,2,3, Okanogan^1,2,3,4,59, Pierce^1,2,3, San Juan³, Spokane^1,2, Stevens^1,2, Thurston^2,133, Yakima^1,2,3,96. Seasonality: Apr², Jun^1,2,3,4,133, Jul^1,2,3,4, Aug^1,2,4 (2018^2,133). Collections: AMNH, BBSL, BugGuide, SEMC, UCRC, WSUC. Floral records: ASTERACEAE: Arnica sororia⁵⁹, Erigeron speciosus⁵⁹, Senecio triangularis⁵⁹, Taraxacum officinale^3,59; FABACEAE: Lupinus^3,59, L. polyphyllus⁸, Trifolium pratense⁵⁹, T. repens^3,59; HYDROPHYLLACEAE: Phacelia leptosepala^8,59; MALVACEAE: Sidalcea oregana³; PLANTAGINACEAE: Penstemon confertus⁵⁹; ROSACEAE: Potentilla gracilis^3,59,133, Rosa nutkana ssp. nutkana⁵⁹

483. Hoplitis (Alcidamea) fulgida (Cresson, 1864). County records: Clallam³, Columbia¹³⁵, Ferry², Grant¹⁰⁴, Kittitas^1,2,3, Okanogan^1,2,3,59, Pierce³, Spokane^1,2,3, Stevens^1,2, Yakima^1,2,3. Seasonality: May^1,2,104, Jun^1,2,3,135, Jul^1,2,3, Aug^1,2,3 (2021¹³⁵). Collections: BBSL, BugGuide, NMDG, INHS, JRYA, SEMC, UCRC, WSUC. Floral records: ASTERACEAE: Achillea millefolium^3,59, Crepis atrabarba⁵⁹, Taraxacum officinale^3,59; BORANGINACEAE: Myosotis laxa^3,59; HYDROPHYLLACEAE: Phacelia leptsepala^3,59, P. heterophylla⁸; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹; RANUNCULACEAE: Delphinium nuttallianum⁸, Ranunculus⁸; ROSACEAE: Physocarpus malvaceus⁸, Potentilla gracilis^3,59

484. Hoplitis (Alcidamea) grinnelli (Cockerell, 1910). County records: Benton^1,2,3, Garfield^1,2,3,46,104, Grant^1,2,4, Klickitat^1,2, Lewis^1,2,4,104, Okanogan^1,2,3,59, Spokane^1,2, Thurston¹³³, Whitman^1,2,3,103. Seasonality: Apr^1,2, May^1,2,3,4,104, Jun^1,2,103,133, Jul¹⁰³, Aug^1,2,3 (2018¹³³). Collections: BBSL, PCYU, SEMC. Floral records: FABACEAE: Astragalus³, Lupinus lepidus¹³³; ROSACEAE: Potentilla gracilis¹³³

485. Hoplitis (Alcidamea) hypocrita (Cockerell, 1906). County records: Benton^1,2,3, Garfield^1,2,3,46, Spokane^1,2,3, Whitman^1,2,3,8, Yakima^1,2,4. Seasonality: May^1,2,3,4, Jun^1,2,3,46, Jul^1,2,3 (2012^1,2). Collections: BBSL, WSUC. Floral records: APIACEAE: Lomatium⁸; ASTERACEAE: Balsamorhiza sagitta⁸; FABACEAE: Astragalus³, A. bungeanus³, A. falcatus³; PLANTAGINACEAE: Penstemon attenuatus⁸

486. Hoplitis (Alcidamea) louisae (Cockerell, 1934). County records: Benton^1,2,3, Kittitas^1,2,3, Thurston¹⁰³, Yakima¹⁰³. Seasonality: Jun^1,2,3, Jul^1,2,3 (1994^1,2,3). Collections: BBSL, SEMC

487. Hoplitis (Alcidamea) producta (Cresson, 1864). County records: Benton^1,2, Klickitat^1,2,104, Okanogan⁵⁹, Skamania^1,2, Spokane^1,2, Thurston¹³³, Wahkiakum^1,2, Whitman^6,104. Seasonality: Apr^1,2, May¹⁰⁴, Jun^1,2,133, Jul^1,2,6,104, Aug^1,2 (2019¹³³). Collections: BBSL. Floral records: ASTERACEAE: Achillea millefolium⁵⁹; FABACEAE: Lupinus lepidus¹³³; ROSACEAE: Potentilla gracilis¹³³

487a. § Hoplitis (Alcidamea) producta subgracilis Michener, 1947. County records: Okanogan^1,2,3, Pierce¹⁰³, Skagit^1,2,3, Whitman¹⁰³. Seasonality: Jun^1,2,3, Jul^1,2,3 (2004^1,2,3). Collections: BBSL. Conservation status: Vulnerable (National Research Council 2005, Shepherd 2005d). Floral records: ASTERACEAE: Achillea millefolium³

488. Hoplitis (Alcidamea) sambuci Titus, 1904. County records: Garfield^1,2,3,46, Klickitat^1,2, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,2,3,96,103. Seasonality: May^1,2,3, Jun^1,2,3,46, Jul^1,2, Aug^1,2 (2015^1,2). Collections: BBSL, NMNH. Holotype. USA, Washington, Whitman County, Pullman; CV Piper; Type No. 66860, USNM ENT 00536520. Floral records: Sambucus glacua⁹⁶

489. †‡ Hoplitis (Alcidamea) spoliata (Provancher, 1888). County records: Whitman^1,3. Seasonality: Jul^1,3 (1908^1,3). Collections: INHS

490. † Hoplitis (Alcidamea) uvulalis (Cockerell, 1902). County records: Okanogan^1,2. Seasonality: Aug^1,2 (2012^1,2). Collections: BBSL

491. Hoplitis (Alcidamea) viridimicans (Cockerell, 1897). County records: Thurston^96,103. Collections: NMNH. Holotype. USA, Washington, Thurston County, Olympia

492. Hoplitis (Formicapis) robusta (Nylander, 1848). County records: Chelan^1,2,3, Garfield^1,2,3, Okanogan^1,2,3,59. Seasonality: Jul^1,2,3, Aug^1,2,3 (2010^1,2,3). Collections: BBSL

493. § Hoplitis (Proteriades) orthognatha (Griswold, 1983). County records: Asotin^102,112. Seasonality: Jun¹⁰² (1973¹⁰²). Collections: WSUC. [= Proteriades orthognathus Griswold, 1983]. Holotype. USA, Washington, Asotin County, Fields Spring, 6.4 km S Anatone; 7 June 1973; M Jackson; WSUC No. 370. Conservation status: Vulnerable (Shepherd 2005e; National Research Council 2007)

Genus Osmia Panzer

494. Osmia (Cephalosmia) californica Cresson, 1864. County records: Benton^1,2,3, Chelan¹³⁶, Franklin^121,129, Grant^1,2,3, Kittitas^1,2,3, Klickitat^1,2, Lincoln^1,2,3, Okanogan^1,2,3,59, Spokane^1,2, Stevens^1,2, Walla Walla^1,2,3, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3,129, Jun^1,2,3, Jul^1,2,3 (2015^1,2). Collections: AMNH, BBSL, INHS, SEMC, WSUC. [= Osmia pascoensis Cockerell, 1897]. Paratype. USA, Washington, Franklin County, Pasco; May; Kincaid; Type No. 6868. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: APIACEAE: Lomatium⁸; ASTERACEAE: Arnica sororia^3,59, Balsamorhiza sagittata⁸, Gaillardia aristata⁸, Senecio hydrophiloides^3,59; FABACEAE: Lupinus sericeus⁵⁹; GROSSULARIACEAE: Ribes aureum⁸

495. † Osmia (Cephalosmia) grinnelli Cockerell, 1910. County records: Yakima⁷. Seasonality: May⁷, Aug⁷ (2012⁷). Collections: WSUC

496. Osmia (Cephalosmia) marginipennis Cresson, 1878. County records: Chelan³, Okanogan^1,2,3,59, Stevens^1,2, Whitman⁹⁷, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jul^1,2,3 (2012^1,2). Collections: BBSL, UCRC. Floral records: ROSACEAE: Potentilla gracilis^3,59

497. Osmia (Cephalosmia) montana Cresson, 1864. County records: Douglas⁷, Kittitas^1,2,3, Klickitat^1,2, Okanogan^1,2,3,4,59, Spokane^1,2, Stevens^1,2, Whitman⁸, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2, Jun^1,2,3, Jul^1,2,3,7, Aug^1,2 (2016^1,2). Collections: BBSL, BugGuide, EMEC, SEMC, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Arnica sororia⁵⁹, Crepis atrabarba⁵⁹, Erigeron speciosus^3,59, Gaillardia aristata⁸, Senecio hydrophiloides⁵⁹, S. triangularis⁵⁹, Taraxacum officinale^3,59; POLEMONIACEAE: Polemonium pulcherrimum^3,59; ROSACEAE: Potentilla gracilis^3,59, Rosa⁸

498. Osmia (Cephalosmia) subaustralis Cockerell, 1900. County records: Clallam³, Okanogan^1,2,3,4,59, Spokane^1,2, Stevens^1,2, Walla Walla^1,2,3, Whitman⁸. Seasonality: Apr^1,2, Jun^1,2,3, Jul^1,2,3,4, Aug^1,2,3,4 (2014^1,2,3). Collections: BBSL, JRYA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Arnica cordifolia⁵⁹, Erigeron speciosus^3,59, Gaillardia aristata⁸, Packera cana³, Senecio⁵⁹, S. triangularis⁵⁹, Taraxacum officinale⁵⁹; ROSACEAE: Fragaria virginiana ssp. platypetala⁵⁹

499. †§ Osmia (Hapsidosmia) iridis Cockerell and Titus, 1902. County records: Garfield⁷, Spokane^1,2. Seasonality: May^1,2, Jul⁷ (2014^1,2). Collections: BBSL, WSUC. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

500. †* Osmia (Helicosmia) caerulescens (Linnaeus, 1758). County records: Clallam², King^1,2,3, Skamania^1,2, Spokane², Thurston^1,2,3, Wahkiakum^1,2, Yakima². Seasonality: May^1,2,3, Jun^1,2, Jul^1,2 (2019^1,2). Collections: BBSL, BugGuide, iNaturalist. [= Osmia coerulescens (Linnaeus, 1758)]. Conservation status: G5 – Secure globally (NatureServe 2024)

501. Osmia (Helicosmia) coloradensis Cresson, 1878. County records: Chelan^1,2,3, Clallam³, Island^1,2,3, King^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Lewis^1,2,4, Okanogan^1,2,3,4,59, Pierce^1,2,3, Spokane^1,2,3, Stevens^1,2, Thurston^1,2,3, Walla Walla^1,2,3, Whatcom^1,2,3, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3,4, Jun^1,2,3, Jul^1,2,3,4, Aug^1,2,3,4 (2016^1,2). Collections: BBSL, JRYA, PCYU, SEMC, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Achillea millefolium^3,59, Agoseris glauca var. dasycephala⁵⁹, Arnica cordifolia⁸, A. sororia⁵⁹, Cirsium vulgare⁵⁹, Erigeron speciosus^3,59, Senecio³, S. hydrophiloides⁵⁹, S. triangularis⁵⁹, Taraxacum officinale^3,59; FABACEAE: Trifolium repens⁸; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹

502. † Osmia (Helicosmia) texana Cresson, 1872. County records: Asotin^2,3, Clark^1,2, Klickitat^1,2, Pierce^1,2,3,4, Wahkiakum^1,2, Whitman^1,4, Yakima⁷. Seasonality: May^1,4, Jun^1,3,4, Jul¹, Aug⁷ (2016¹). Collections: BBSL, PCYU, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024)

503. Osmia (Melanosmia) aglaia Sandhouse, 1939. County records: Whitman³². Seasonality: May³² (2012³²). Conservation status: G5 – Secure globally (NatureServe 2024)

504. Osmia (Melanosmia) albolateralis Cockerell, 1906. County records: Benton^1,2,3, Chelan¹³⁶, Garfield^1,2,3,46, Kittitas^2,3, Klickitat^1,2, Lincoln^2,3, Okanogan^1,2,3,4,59, Skagit⁷, Skamania^1,2, Spokane^1,2, Stevens^1,2, Wahkiakum^1,2, Whitman^1,2,3,6, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3,6,7, Jul^1,2,3,7, Aug^1,2,3,4 (2016^1,2). Collections: BBSL, SEMC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Taraxacum officinale^3,59; BORAGINACEAE: Myosotis laxa⁵⁹; FABACEAE: Astragalus miser var. miser^3,59; LAMIACEAE: Salvia dorrii³, PLANTAGINACEAE: Penstemon confertus^3,59; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹

505. † Osmia (Melanosmia) atriventris Cresson, 1864. County records: Whitman^2,3. Seasonality: (2003^2,3). Collections: BBSL. Conservation status: G5 – Secure globally (NatureServe 2024)

506. Osmia (Melanosmia) atrocyanea Cockerell, 1897. County records: Chelan^1,2,3, Clark^1,2, Garfield^1,2,3,46, Klickitat^1,2,3, Lincoln^2,3, Okanogan^1,2,3,59, Spokane^1,2,3, Stevens^1,2, Thurston^1,2,129, Walla Walla^1,2,3, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2, Jun^1,2,3, Jul^1,2,3,129 (2015^1,2). Collections: BBSL, NMNH, SEMC, WSUC. Holotype. USA, Washington, Thurston County, Olympia; 4 July 1896; Type No. 28209, USNM ENT 00536700. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Balsamorhiza sagittata⁸; FABACEAE: Astragalus bungeanus³, Lupinus polyphyllus⁸, Trifolium repens^3,59, Vicia villosa⁸; PLANTAGINACEAE: Penstemon confertus^3,59; ROSACEAE: Malus domestica⁸

507. †§ Osmia (Melanosmia) austromaritima Michener, 1936. County records: Benton^1,2, Spokane^1,2. Seasonality: Apr^1,2, May^1,2, Jun^1,2 (2014^1,2). Collections: BBSL. [= Osmia hurdi White, 1952]. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

508. † Osmia (Melanosmia) bella Cresson, 1878. County records: Grant^1,2,3, Kittitas^1,2,3, Klickitat^1,2,3, Okanogan^1,2,3, Pierce^1,2,3, San Juan^1,2,3. Seasonality: Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2004^1,2,3). Collections: BBSL

509. Osmia (Melanosmia) brevis Cresson, 1864. County records: Kittitas^2,3, Klickitat^1,2,3, Okanogan^1,2,3,4,59, Spokane^1,2,3, Stevens^1,2, Whitman^1,2,3,4,8, Yakima^1,2,3. Seasonality: May^1,2,3,4, Jun^1,2,3, Jul^1,2,3,4, Aug^1,2,3,4 (2015^1,2). Collections: BBSL, INHS, PCYU WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Agoseris glauca var. dasycephala^3,59, Erigeron speciosus⁵⁹; FABACEAE: Trifolium repens⁸, Vicia villosa⁸; HYDROPHYLLACEAE: Phacelia heterophylla⁸; PLANTAGINACEAE: Penstemon confertus^3,59, P. serrulatus³, P. washingtonensis⁵⁹

510. Osmia (Melanosmia) bruneri Cockerell, 1897. County records: Benton^1,2,3, Chelan¹³⁶, Columbia^1,2,3, Garfield^1,2,3,46, Grant^1,2,3, Kittitas^1,2,3, Spokane^1,2, Stevens^1,2, Walla Walla³, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3, Jun^1,2,3, Jul^1,2,3 (2015^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral record: FABACEAE: Astragalus³, Trifolium³; LAMIACEAE: Salvia dorrii³

511. Osmia (Melanosmia) bucephala Cresson, 1864. County records: Clark^1,2, Garfield^1,2,3,46, Jefferson^1,2, King^1,2,3, Kitsap^1,2,3, Okanogan^1,2,3,59, San Juan^1,2,3,136, Skamania^1,2, Stevens^1,2, Thurston^40,129, Wahkiakum^1,2, Whatcom⁷, Whitman^1,2,3,40. Seasonality: Apr^1,2, May^1,2,3,40, Jun^{1,2,3,7,40,129}, Jul^1,2,3 (2017¹³⁶). Collections: BBSL, CUIC, NMNH, SEMC, UCRC, WSUC. [= Osmia subornata Cockerell, 1897]. Paratype. USA, Washington, Thurston County, Olympia; 1 June 1894; Type No. 6879, USNM ENT 00536996. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus miser var. serotinus³, Lathyrus japonicus^7,136; OLEACEAE: Syringa³

512. †‡ Osmia (Melanosmia) cahuilla Cooper, 1993. County records: Pierce^1,2,3. Seasonality: Jul^1,2,3 (1920^1,2,3). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

513. Osmia (Melanosmia) calla Cockerell, 1897. County records: Benton^1,2,3, Klickitat^1,2, Spokane^1,2, Thurston¹²⁹, Whitman^1,2,3,6,8. Seasonality: May^1,2, Jun^1,2,6, Jul^1,2,3, Aug^1,2 (2015^1,2). Collections: BBSL, NMNH, WSDA, WSUC. Paratype. USA, Washington, Thurston County, Olympia; Kincaid; Type No. 6866. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus³, Vicia villosa⁸; HYDROPHYLLACEAE: Phacelia hastata³

514. †‡ Osmia (Melanosmia) cara Cockerell, 1910. County records: Kittitas^1,2,3. Seasonality: Jul^1,2,3 (1935^1,2,3). Collections: BBSL

515. † Osmia (Melanosmia) cobaltina Cresson, 1878. County records: Chelan^1,2,3, Franklin^1,2,3, Grant^1,2,3, Whitman^2,3. Seasonality: Apr^1,2,3, May^1,2,3 (1977^1,2,3). Collections: BBSL, INHS

516. Osmia (Melanosmia) cyanella Cockerell, 1897. County records: Asotin³, Chelan^1,2,3, King^1,2,3, Klickitat^1,2, Thurston^1,2,3,129, Yakima^1,2,4. Seasonality: May^1,2,3,4, Jun^1,2, Jul^1,2,3, Aug^1,2 (2012^1,2). Collections: BBSL, EMEC, NMNH, UCRC. Type. USA, Washington, Thurston County, Olympia; May; Kincaid; Type No. 6364

517. Osmia (Melanosmia) cyanopoda Cockerell, 1916. County records: Benton^1,2,3, Garfield^1,2,3,46, Walla Walla^1,2. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3 (2012^1,2). Collections: BBSL. Floral records: FABACEAE: Astragalus³

518. Osmia (Melanosmia) dakotensis Michener, 1937. County records: Benton^1,2, Garfield^1,2,46. Seasonality: May^1,2 (1998^1,2). Collections: BBSL. [= Osmia (Melanosmia) cockerelli Sandhouse, 1939]. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

519. † Osmia (Melanosmia) densa Cresson, 1864. County records: Chelan^1,2,3, Clallam³, Garfield^1,2,3, Island^1,2,3, King^1,2,3, Kittitas^1,2,3, Klickitat^1,2, San Juan^1,2,3, Spokane^1,2, Stevens^1,2, Whatcom³, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3 (2016^1,2). Collections: BBSL, JRYA, OSUC, UCRC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: FABACEAE: Onobrychis³, Trifolium repens³; MALVACEAE: Sidalcea oregana³

520. Osmia (Melanosmia) dolerosa Sandhouse, 1939. County records: Chelan³, Clallam³, King^1,2,3,100, Kitsap^1,2,3, Klickitat^1,2, Okanogan^1,2,3, Pacific^1,2,3, Pierce^1,2,3, San Juan^2,3,100,136, Thurston¹⁰⁰, Whitman³. Seasonality: Apr^1,2,3, May^1,2,3,100, Jun^1,2,3,100, Jul^1,2,3,100, Aug³ (2017¹³⁶). Collections: BBSL, JRYA, SEMC, UCRC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Trifolium hybridum³; ROSACEAE: Rubus bifrons¹³⁶, R. ursinus³

521. † Osmia (Melanosmia) ednae Cockerell, 1907. County records: Spokane^1,2, Whitman^1,2,4. Seasonality: May^1,2,4 (2014^1,2). Collections: BBSL, PCYU. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

522. Osmia (Melanosmia) exigua Cresson, 1878. County records: Klickitat^1,2, Okanogan^1,2,3,59, Spokane^1,2, Stevens^1,2, Thurston¹³³, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,133, Jun^1,2,3,133, Jul^1,2,3, Aug^1,2 (2019¹³³). Collections: BBSL. Floral records: ASTERACEAE: Hypochaeris radicata¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; FABACEAE: Lupinus albicaulis¹³³, L. lepidus¹³³, Trifolium repens^3,59

523. Osmia (Melanosmia) giliarum Cockerell, 1906. County records: Adams^2,101, King¹⁰¹, Kittitas^1,2, Klickitat^1,2, Thurston¹⁰¹, Walla Walla^1,2,101, Whitman^1,2,101, Yakima^1,2,101. Seasonality: May^1,2,101, Jun^1,2,101, Jul^1,2,101 (2012^1,2). Collections: BBSL, SEMC. [= Osmia physariae Cockerell, 1907]. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

524. †‡ Osmia (Melanosmia) grindeliae Cockerell, 1910. County records: Chelan^1,2,3. Seasonality: Jul^1,2,3 (1930^1,2,3). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

525. Osmia (Melanosmia) inermis (Zetterstedt, 1838). County records: King^1,2,3,31. Collections: BBSL. Conservation status: G5 – Secure globally (NatureServe 2024)

526. Osmia (Melanosmia) integra Cresson, 1878. County records: Adams⁷, Benton^1,2,3, Chelan^1,2,3, Garfield^1,2,3,46, Grant^1,2,3,4, Kittitas^1,2,3, Walla Walla^1,2,3,101, Yakima^1,2,3. Seasonality: Apr^1,2,3,7,101, May^1,2,3,4,101 (2014^1,2). Collections: BBSL, LACM, PCYU, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus bungeanus³; LAMIACEAE: Salvia dorrii³

527. † Osmia (Melanosmia) inurbana Cresson, 1878. County records: Garfield^1,2,3, Thurston¹³³, Walla Walla^1,2,3, Whitman^1,2,3. Seasonality: May^1,2,3,133, Jun^1,2,3,133, Jul¹³³ (2020¹³³). Collections: BBSL, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Crepis capillaris¹³³, Hypochaeris radicata¹³³; CAPRIFOLIACEAE: Plectritis congesta¹³³; FABACEAE: Lupinus bicolor¹³³, L. lepidus¹³³; HYPERICACEAE: Hypericum perforatum¹³³; ROSACEAE: Potentilla gracilis¹³³

528. Osmia (Melanosmia) juxta Cresson, 1864. County records: Asotin⁷, Chelan^1,2,3, Ferry³, King^1,2,3, Kittitas³, Klickitat^1,2, Lewis^1,2,4, Okanogan^1,2,3,4,59, San Juan^1,2,3, Spokane^1,2, Stevens^1,2,3, Thurston^1,2,3, Whitman⁶. Seasonality: Apr^1,2, May^1,2,3,4, Jun^1,2,3,4,6,7, Jul^1,2,3, Aug^1,2,3,4 (2015^1,2). Collections: BBSL, EMEC, LACM, OSUC, PCYU, UCRC, WSDA, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Arnica cordifolia⁵⁹, Erigeron speciosus^3,59, Microseris nutans⁵⁹, Taraxacum officinale⁵⁹; FABACEAE: Trifolium repens^3,59; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; ONAGRACEAE: Chamerion angustifolium ssp. angustifolium⁸; PLANTAGINACEAE: Penstemon confertus^3,59

529. Osmia (Melanosmia) kincaidii Cockerell, 1897. County records: Benton^1,2,3, Klickitat^1,2, Okanogan^1,2, Pierce^1,2,3, Skagit^1,2,3, Spokane^1,2, Stevens^1,2, Thurston^1,2,3,129. Seasonality: Apr^1,2, May^1,2, Jun^1,2,3, Jul^1,2,3, Aug^1,2 (2016^1,2). Collections: BBSL, NMNH, WSUC. Lectotype. USA, Washington, Thurston County, Olympia; 2 June 1894; Type No. 3710, USNM ENT 00536951. Paratype. USA, Washington, Thurston County, Olympia; Kincaid; Type No. 6867. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: HYDROPHYLLACEAE: Phacelia heterophylla⁸; PLANTAGINACEAE: Collinsia parviflora⁸

530. † Osmia (Melanosmia) laeta Sandhouse, 1924. County records: Klickitat^1,2, Okanogan^2,4. Seasonality: Jun^1,2, Jul^2,4, Aug^2,4 (2012^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

531. †§‡ Osmia (Melanosmia) lanei Sandhouse, 1939. County records: Yakima^1,2,3. Seasonality: Jun^1,2,3 (1927^1,2,3). Collections: NMNH. Holotype. USA, Washington, Yakima County, Naches River; 8 June 1927; MC Lane; Type No 52872, USNM ENT 00536953. Conservation status: G3 – Vulnerable globally, possibly extirpated in Washington (NatureServe 2024)

532. Osmia (Melanosmia) longula Cresson, 1864. County records: Benton^1,2,3, Chelan¹³⁶, Kittitas^1,2,3, Okanogan^1,2,3,4,59, Spokane^1,2, Thurston¹²⁹, Whitman^1,2,6, Yakima^1,2,3. Seasonality: Apr^1,2,3, May¹²⁹, Jun^1,2,3,6, Jul^1,2,3, Aug^1,2,3,4 (2018^1,2,3). Collections: BBSL, iNaturalist, WSDA. [= Osmia grandior Cockerell, 1897]. Paratype. USA, Washington, Thurston County, Olympia; 10 May 1894; Kincaid; Type No. 6869, USNM ENT 00536934. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus columbianus³, A. miser var. miser⁵⁹; PLANTAGINACEAE: Penstemon washingtonensis^3,59

533. † Osmia (Melanosmia) malina Cockerell, 1909. County records: Chelan^1,2,3, Clallam^1,2,3, King^1,2,3, Klickitat^1,2, Wahkiakum^1,2. Seasonality: May^1,2,3, Jun^1,2, Jul^1,2,3, Aug^1,2 (2011^1,2). Collections: BBSL, OSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: MALVACEAE: Sidalcea oregana³

534. Osmia (Melanosmia) melanopleura Cockerell, 1916. County records: Klickitat^1,2, Spokane^1,2, Stevens^1,2, Whitman^1,2,3,40. Seasonality: Apr^1,2, May^1,2,3,40, Jun^1,2 (2016^1,2). Collections: BBSL, INHS, SEMC. [= Osmia bakeri Sandhouse, 1924]

535. Osmia (Melanosmia) nanula Cockerell, 1897. County records: King^{1,2,3,100,129}, Okanogan^1,2, Skamania^1,2, Spokane^1,2, Walla Walla^1,2,3, Whitman^1,2,3,8. Seasonality: May^1,2,3,129, Jun^1,2,3, Jul^1,2, Aug^1,2 (2016^1,2). Collections: BBSL, INHS, NMNH, SEMC, WSUC. Type. USA, Washington, King County, Seattle; 19 May 1896; Type No. 6865, USNM ENT 00536968. [= Osmia phaceliae Cockerell, 1907]. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: GERANIACEAE: Geranium viscosissimum⁸; RANUNCULACEAE: Ranunculus⁸

536. Osmia (Melanosmia) nemoris Sandhouse, 1924. County records: Benton^1,2, Klickitat^1,2, Spokane^1,2, Thurston^1,2, Walla Walla^1,2,3, Whitman^1,2,3,8. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2, Aug^1,2 (2014^1,2). Collections: BBSL, MCZ, SEMC, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Arnica cordifolia⁸, Balsamorhiza sagittata⁸

537. ‡ Osmia (Melanosmia) nifoata Cockerell, 1909. County records: Whitman^1,2,3,101, Yakima^1,2,3,101. Seasonality: Jun¹⁰¹, Jul^1,2,3,101 (1904¹⁰¹). Collections: BBSL, SEMC, WSUC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Senecio³

538. Osmia (Melanosmia) nigrifrons Cresson, 1878. County records: Adams⁷, Benton^1,2,3, Garfield^1,2,3,46, King^1,2,3, Klickitat^1,2, Stevens^1,2, Whitman^1,2,3,8,101. Seasonality: Apr^1,2,3, May^{1, 2,3,7,101}, Jun^1,2,3,101 (2012^1,2). Collections: AMNH, BBSL, EMEC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Balsamorhiza sagittata⁸; FABACEAE: Astragalus³, Trifolium³, Vicia villosa⁸

539. Osmia (Melanosmia) nigriventris (Zetterstedt, 1838). County records: Okanogan^1,2,3,31,59, Pierce^1,2,3, Stevens^1,2, Whatcom^1,2,3. Seasonality: Jun^1,2, Jul^1,2,3,31 (2014^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

540. §‡ Osmia (Melanosmia) nigrobarbata Cockerell, 1916. County records: Walla Walla^1,2,3,101. Seasonality: May^1,2,3,101 (1937^1,2,3,101). Collections: SEMC. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

541. †§ Osmia (Melanosmia) obliqua White, 1952. County records: Klickitat^1,2, Spokane^1,2. Seasonality: May^1,2, Jun^1,2 (2014^1,2). Collections: BBSL. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

542. § Osmia (Melanosmia) odontogaster Cockerell, 1897. County records: King^1,2,3, Okanogan^1,2,3,59, Thurston^{1,2,3,101,129}, Whitman^1,2,3,101. Seasonality: Apr^1,2, May^1,2,3,101, Jun^1,2,3,101, Jul^1,2,3 (2004^1,2,3,59). Collections: BBSL, NMNH, SEMC. Paratype. USA, Washington, Thurston County, Olympia; Kincaid; Type No. 3709. Conservation status: G2 – Imperiled globally (NatureServe 2024). Floral records: ASTERACEAE: Erigeron nivalis⁵⁹, Senecio hydrophiloides^3,59; FABACEAE: Trifolium pratense⁵⁹, T. repens^3,59; ROSACEAE: Potentilla gracilis^3,59, Rubus ursinus³

543. Osmia (Melanosmia) paradisica Sandhouse, 1924. County records: Chelan³, Okanogan^1,2,3,4,59, Pierce^1,2,3, Skagit³, Stevens^1,2, Whatcom³. Seasonality: Jun^1,2, Jul^1,2,3,4, Aug^1,2,3,4 (2016^1,2). Collections: BBSL, JRYA. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Anaphalis margaritacea^3,59, Erigeron speciosus^3,59, Senecio integerrimus⁵⁹; CRASSULACEAE: Sedum lanceolatum⁵⁹; FABACEAE: Lupinus^3,59; PLANTAGINACEAE: Penstemon washingtonensis⁵⁹; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹; ROSACEAE: Potentilla gracilis^3,59

544. Osmia (Melanosmia) pentstemonis Cockerell, 1906. County records: Clallam³, Kittitas^2,3, Klickitat^1,2, Okanogan^1,2,3,4,59, Pierce^1,2,3, Stevens^1,2, Whitman^1,2,3,8, Yakima^1,2,3. Seasonality: Jun^1,2,3, Jul^1,2,3,4, Aug^1,2,3,4, Sep³ (2016^1,2). Collections: BBSL, JRYA, SEMC, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Erigeron speciosus⁵⁹, Senecio triangularis⁵⁹, Taraxacum officinale⁵⁹; FABACEAE: Trifolium repens^3,59; ONAGRACEAE: Gayophytum diffusum ssp. parviflorum^3,59; PLANTAGINACEAE: Penstemon albertinus⁸, P. serrulatus³, P. washingtonensis⁵⁹; ROSACEAE: Fragaria virginiana ssp. platypetala⁵⁹

545. Osmia (Melanosmia) pikei Cockerell, 1907. County records: King^1,2,3,40, Okanogan^1,2,3,59, Thurston⁴⁰. Seasonality: Apr^1,2, May^1,2,3, Jul^1,2,3 (2004^1,2,3,59). Collections: BBSL, EMEC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Balsamorhiza sagittata⁸; ROSACEAE: Rubus ursinus³

546. Osmia (Melanosmia) proxima Cresson, 1864. County records: Clark^1,2, Garfield^1,2,3,46, Jefferson^1,2, Klickitat^1,2, Okanogan^1,2,3,59, San Juan¹³⁶, Skamania^1,2, Spokane^1,2,3, Stevens^1,2, Wahkiakum^1,2, Whitman^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3, Jul^1,2, Aug^1,2,3 (2017¹³⁶). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: CONVOLVULACEAE: Calystegia soldanella¹³⁶; FABACEAE: Astragalus miser³; ROSACEAE: Rubus bifrons¹³⁶

547. †§ Osmia (Melanosmia) pulsatillae Cockerell, 1907. County records: King^1,2,3, Whitman^1,2,3. Seasonality: May^1,2 (2003^1,2,3). Collections: BBSL, OSUC, SEMC. Conservation status: G2 – Imperiled globally (NatureServe 2024)

548. Osmia (Melanosmia) pusilla Cresson, 1864. County records: Benton^1,2,3, Clallam³, Clark^1,2, Cowlitz^1,2,3, Garfield^1,2,3,46, Klickitat^1,2, Okanogan^1,2,3,4,59, Pierce^1,2,3, Skamania^1,2, Spokane^1,2, Stevens^1,2, Whatcom^1,2,3, Whitman^1,2,3,6. Seasonality: May^1,2,3, Jun^1,2,3,6, Jul^1,2,3,4,6, Aug^1,2,3, Sep^1,2 (2016^1,2). Collections: BBSL, INHS, JRYA, WSDA. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Anaphalis margaritacea^3,59, Erigeron speciosus^3,59, Taraxacum officinale⁵⁹; BORAGINACEAE: Myosotis laxa⁵⁹; FABACEAE: Astragalus chaborasicus³, Lupinus sericeus⁵⁹, Onobrychis³, Trifolium repens^3,59; HYDROPHYLLACEAE: Phacelia leptosepala⁵⁹; PLANTAGINACEAE: Penstemon confertus⁵⁹; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹; ROSACEAE: Fragaria virginiana ssp. platypetala^3,59, Potentilla gracilis^3,59

549. Osmia (Melanosmia) raritatis Michener, 1957. County records: Klickitat^1,2, Spokane^1,2, Yakima⁴⁰. Seasonality: Apr^1,2, May^1,2,40 (2012^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

550. † Osmia (Melanosmia) rawlinsi Sandhouse, 1939. County records: Chelan^1,2,3, Grant^1,2,3, Walla Walla^1,2, Yakima^1,2,3. Seasonality: Apr^1,2,3, May^1,2,3 (2012^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: LAMIACEAE: Salvia dorrii³

551. Osmia (Melanosmia) regulina Cockerell, 1911. County records: Garfield^1,2,3,46, Klickitat^1,2, Walla Walla^1,2,3,71. Seasonality: Jun^1,2,3, Aug^1,2,3 (2012^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus cicer³

552. Osmia (Melanosmia) sculleni Sandhouse, 1939. County records: Klickitat^1,2, Okanogan^1,2,3,59, Spokane^1,2. Seasonality: Apr^1,2, May^1,2, Jun^1,2, Jul^1,2, Aug^1,2,3 (2015^1,2). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Arnica cordifolia^3,59

553. † Osmia (Melanosmia) sedula Sandhouse, 1924. County records: Klickitat^1,2, Thurston^1,2. Seasonality: May^1,2, Jun^1,2 (2011^1,2). Collections: BBSL. [= Osmia claremontensis Michener, 1936]. Conservation status: G5 – Secure globally (NatureServe 2024)

554. Osmia (Melanosmia) simillima Smith, 1853. County records: Clallam³, Garfield^1,2,3,46, Island^1,2,3, Jefferson^1,2, King^1,2,3, Pacific^1,2,3, Spokane^1,2, Stevens^1,2, Thurston^1,2,3, Whatcom⁷, Whitman^1,2,3,6, Yakima^1,2,3. Seasonality: Apr^1,2, May^1,2,3, Jun^1,2,3,6,7, Jul^1,2,3, Aug^1,2,3 (2016^1,2). Collections: BBSL, EMEC, JRYA, SEMC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: FABACEAE: Astragalus chaborasicus³, Lathyrus japonicus⁷, Trifolium repens³

555. Osmia (Melanosmia) tanneri Sandhouse, 1939. County records: Okanogan^1,2,3,4,59. Seasonality: Jul^1,2,3,4, Aug^1,2 (2004^1,2,3,4,59). Collections: BBSL. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: FABACEAE: Oxytropis campestris var. cusickii⁵⁹; PLANTAGINACEAE: Penstemon washingtonensis⁵⁹; POLEMONIACEAE: Polemonium pulcherrimum⁵⁹; ROSACEAE: Dryas hookeriana⁵⁹

556. †§ Osmia (Melanosmia) thysanisca Michener, 1957. County records: Whitman⁷, Yakima^1,2. Seasonality: Apr⁷, Jul^1,2 (1973⁷). Collections: SEMC, WSUC. Conservation status: G3 – Vulnerable globally (NatureServe 2024)

557. Osmia (Melanosmia) trevoris Cockerell, 1897. County records: Benton^1,2,3, Clark^1,2, Columbia^1,2,3, Franklin⁹⁷, Garfield^1,2,3,4,46, King^1,2,3,129, Kittitas^1,2,3, Klickitat^1,2, Okanogan^1,2,3,4,59, Skamania^1,2, Spokane^1,2,3, Stevens^1,2, Thurston^1,2,3, Walla Walla^1,2,3, Whitman^1,2,3,6,7. Seasonality: Apr^1,2,3, May^1,2,3,4,129, Jun^1,2,3,4,6,7, Jul^1,2,3,6, Aug^1,2,3,4 (2016^1,2). Collections: BBSL, INHS, NMNH, PCYU, SEMC, WSDA, WSUC. Type. USA, Washington, King County, Seattle; 19 May 1896; Type No. 1895, USNM ENT 00537003. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Erigeron corymbosus^3,59, E. speciosus^3,59; FABACEAE: Astragalus³

558. †§ Osmia (Melanosmia) trifoliama Sandhouse, 1939. County records: Klickitat^1,2, San Juan^1,2,3. Seasonality: Jul^1,2, Aug^1,2 (2011^1,2). Collections: BBSL, PWRC. Conservation status: G3 – Vulnerable globally, possibly extirpated in Washington (NatureServe 2024)

559. Osmia (Melanosmia) tristella Cockerell, 1897. County records: Chelan³, Clallam^1,2,3, King^1,2,3, Okanogan^1,2,3,4,59, Pierce^1,2,3, Spokane^1,2, Stevens^1,2, Thurston^1,2,3,129, Walla Walla⁷, Yakima^1,2,3. Seasonality: Jan^1,2, Mar^1,2, Apr^1,2,3, May^1,2,3,7, Jun^1,2,3, Jul^1,2,3, Aug^1,2,3,4 (2015^1,2). Collections: BBSL, EMEC, JRYA, NMNH, WSUC. Type. USA, Washington, Thurston County, Olympia; Kincaid; Type No. 6863, USNM ENT 00537005. Conservation status: G4 – Apparently Secure globally (NatureServe 2024). Floral records: ASTERACEAE: Agoseris glauca var. dasycephala⁵⁹, Arnica cordifolia⁵⁹, Erigeron speciosus^3,59, Senecio triangularis⁵⁹, Taraxacum officinale⁵⁹; FABACEAE: Lupinus⁵⁹, Trifolium pratense^3,59, T. repens⁵⁹; HYDROPHYLLACEAE: Phacelia leptsepala⁵⁹; ONAGRACEAE: Gayophytum diffusum spp. parviflorum^3,59; OROBRANCHACEAE: Castilleja miniata⁵⁹; PLANTAGINACEAE: Penstemon³, P. confertus⁵⁹; POLEMONIACEAE: Polemonium pulcherrimum^3,59; ROSACEAE: Fragaria virginiana ssp. platypetala⁵⁹, Potentilla gracilis⁵⁹

560. Osmia (Melanosmia) unca Michener, 1937. County records: Benton^1,2, Garfield⁴⁶, Walla Walla^1,2,3, Whitman^1,2,3,101. Seasonality: Apr^1,2, May^1,2,3,101, Jun^1,2,3 (2014^1,2). Collections: BBSL, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

561. Osmia (Melanosmia) vandykei Sandhouse, 1924. County records: Benton^1,2, Klickitat^1,2, Spokane^1,2, Whitman^1,2,3,40. Seasonality: Mar^1,2,3, Apr^1,2, May^1,2, Jun^1,2 (2016^1,2). Collections: BBSL, SEMC. Conservation status: G4 – Apparently Secure globally (NatureServe 2024)

562. †* Osmia (Osmia) cornifrons (Radoszkowski, 1887). County records: King², Thurston^1,2. Seasonality: Mar^1,2, Apr² (2021^1,2). Collections: BugGuide, iNaturalist. Conservation status: G5 – Secure globally (NatureServe 2024)

563. Osmia (Osmia) lignaria Say, 1837. County records: Adams³, Chelan^1,2,3, Clallam^1,2,3, Clark^1,2, Cowlitz^1,2, Ferry², Grant^1,2,3, Island^1,2,3, Jefferson^1,2, King^1,2,3, Kitsap^1,2,3, Klickitat^1,2, Mason^1,2, Okanogan^1,2,3, Pacific^1,2,3, Pierce^1,2,3, San Juan^1,2,3, Skagit^2,3,10, Snohomish^1,2,3, Spokane^1,2,3, Stevens^1,2,3, Thurston^1,2,3,6,133, Walla Walla^2,3, Whatcom^1,2,3, Whitman^1,2,3, Yakima^1,2,3. Seasonality: Feb^1,2, Mar^1,2,3, Apr^1,2,3, May^1,2,3,133, Jun^1,2,3,6, Jul^1,2, Aug^1,2,3, Nov³, Dec^1,2 (2022^1,2). Collections: BBSL, BugGuide, CUIC, iNaturalist, INHS, NCSU, PMNH, SEMC, UCMC, WSDA, WSUC. Conservation status: G5 – Secure globally (NatureServe 2024). Floral records: ASPARAGACEAE: Camassia quamash¹³³; ASTERACEAE: Arnica cordifolia⁸, Taraxacum³; FABACEAE: Astragalus sinuatus³; HYDROPHYLLACEAE: Phacelia heterophylla⁸

Genus Protosmia Ducke

564. Protosmia (Chelostomopsis) rubifloris (Cockerell, 1898). County records: Chelan^1,2,130, King^1,2,96, Okanogan^1,2, Thurston^1,2,104. Seasonality: Apr^130,104, May^1,2, Jun^1,2 (2021^1,2). Collections: BBSL, iNaturalist, NMNH. [= Chelynia rubifloris Cockerell, 1898]. Holotype. USA, Washington, King County, Seattle. Floral records: BORAGINACEAE: Hackelia venusta⁷

Melittidae: Melittinae: Macropidini

Genus Macropis Panzer

565. §‡ Macropis (Macropis) steironematis opaca Michener, 1938. County records: Yakima^1,2,45,112. Seasonality: Jul^1,2,45,112 (1882^1,2,45,112). Collections: MCZ. Holotype. USA, Washington Territory, Yakima River, Morgan’s Ferry; 1 July 1882; MCZ Type 23415, MCZ-ENT 00023415. Conservation status: Critically Endangered (National Research Council 2007)

Bee species likely to occur in Washington

Andrenidae

Andrena (Achandrena) angustella Cockerell, 1936

Andrena (Andrena) edwardsi Viereck, 1916

Andrena (Callandrena) vulpicolor Cockerell, 1897

Andrena (Cnemidandrena) apacheorum Cockerell, 1897

Andrena (Derandrena) vandykei Cockerell, 1936

Andrena (Diandrena) ablegata (Cockerell, 1922)

Andrena (Melandrena) regularis Malloch, 1917

Andrena (Parandrena) concinnula Cockerell, 1898

Andrena (Parandrena) gibberis Viereck, 1924

Andrena (Parandrena) papagorum Viereck & Cockerell, 1914

Andrena (Ptilandrena) penemisella LaBerge & Ribble, 1975

Andrena (Scaphandrena) cruciferarum Ribble, 1974

Andrena (Scaphandrena) plana Viereck, 1904

Calliopsis (Nomadopsis) anthidius Fowler, 1899

Panurginus beardsleyi (Cockerell, 1904)

Perdita (Perdita) claypolei limatula Timberlake, 1962¹

Perdita (Perdita) exclamans Cockerell, 1895

Perdita (Perdita) fallax Cockerell, 1896

Perdita (Perdita) nuda Cockerell, 1896

Perdita (Perdita) oreophila Timberlake, 1964

Perdita (Perdita) stottleri Cockerell, 1896

Perdita (Perdita) subfasciata Cockerell, 1897

Perdita (Perdita) zebrata Cresson, 1878

Perdita (Pygoperdita) mormonica Timberlake, 1956

Protandrena (Pterosarus) innuptus (Cockerell, 1896)

Protandrena (Pterosarus) irregularis (Cockerell, 1922)

Apidae

Anthophora (Micranthophora) maculifrons Cresson, 1879

Anthophora (Pyganthophora) lesquerellae (Cockerell, 1896)

Biastes (Neopasites) fulviventris (Cresson, 1878)^*

Bombus (Psithyrus) variabilis (Cresson, 1872)²

Eucera (Synhalonia) chrysophila (Cockerell, 1914)

Eucera (Synhalonia) cordleyi (Viereck, 1905)

Melecta edwardsii Cresson, 1879

Melissodes (Callimelissodes) lustrus LaBerge, 1961

Melissodes (Callimelissodes) minusculus LaBerge, 1961

Melissodes (Callimelissodes) nigracauda LaBerge, 1961^*

Melissodes (Eumelissodes) confusus Cresson, 1878

Melissodes (Melissodes) tepidus yumensis LaBerge, 1956

Nomada accepta Cresson, 1878

Nomada calloxantha Cockerell, 1921

Nomada citrina rufula Cockerell, 1903

Nomada depressa Cresson, 1863

Nomada erythraea Dalla Torre, 1896

Nomada hemphilli Cockerell, 1903

Nomada opposita Cresson, 1878³

Nomada scitiformis Cockerell, 1903

Nomada taraxacella Cockerell, 1903

Nomada ultimella Cockerell, 1903

Nomada valida Smith, 1854

Nomada vicinalis vicinalis Cresson, 1878

Triepeolus balteatus Cockerell, 1921

Triepeolus bihamatus (Cockerell, 1907)

Triepeolus utahensis (Cockerell, 1921)

Xenoglossa (Peponapis) pruinosa (Say, 1837)

Halictidae

Agapostemon (Agapostemon) melliventris Cresson, 1874

Dieunomia nevadensis (Cresson, 1874)

Dufourea dilatipes Bohart, 1948^*

Lasioglossum (Dialictus) abundipunctum Gibbs, 2010

Lasioglossum (Dialictus) pavoninum (Ellis, 1913)

Lasioglossum (Dialictus) planatum (Lovell, 1905)

Lasioglossum (Dialictus) sagax (Sandhouse, 1924)

Lasioglossum (Dialictus) subversans (Mitchell, 1960)

Lasioglossum (Dialictus) yukonae Gibbs, 2010

Lasioglossum (Hemihalictus) diatretum (Vachal, 1904)

Lasioglossum (Hemihalictus) pulveris (Cockerell, 1930)

Lasioglossum (Lasioglossum) paraforbesii McGinley, 1986

Lasioglossum (Sphecodogastra) nigrum (Viereck, 1903)

Lasioglossum (Sphecodogastra) peraltum (Cockerell, 1901)

Sphecodes confertus Say, 1837^***

Sphecodes eustictus Cockerell, 1906

Sphecodes lautipennis Cockerell, 1908

Sphecodes patruelis Cockerell, 1913

Megachilidae

Anthidiellum (Loyolanthidium) ehrhorni (Cockerell, 1900)

Anthidium (Anthidium) maculosum Cresson, 1878

Anthidium (Anthidium) palliventre Cresson, 1878

Anthidium (Anthidium) placitum Cresson, 1879

Ashmeadiella (Ashmeadiella) gillettei Titus, 1904

Atoposmia (Atoposmia) abjecta (Cresson, 1878)

Atoposmia (Atoposmia) oregona (Michener, 1943)

Coelioxys (Synocoelioxys) alternatus Say, 1837

Coelioxys (Synocoelioxys) apacheorum Cockerell, 1900

Coelioxys (Boreocoelioxys) banksi Crawford, 1914

Coelioxys (Cyrtocoelioxys) deani Cockerell, 1909

Coelioxys (Paracoelioxys) funerarius Smith, 1854

Coelioxys (Synocoelioxys) hunteri Crawford, 1914

Coelioxys (Boreocoelioxys) porterae Cockerell, 1900

Hoplitis (Proteriades) boharti (Timberlake & Michener, 1950)

Hoplitis (Proteriades) linsdalei Michener, 1947

Megachile (Litomegachile) gentilis Cresson, 1872

Megachile (Megachile) inermis Provancher, 1888

Megachile (Litomegachile) lippiae Cockerell, 1900⁴

Megachile (Chelostomoides) odontostoma Cockerell, 1924

Megachile (Megachiloides) pseudonigra Mitchell, 1927

Megachile (Pseudocentron) sidalceae Cockerell, 1897

Osmia (Melanosmia) cyaneonitens Cockerell, 1906^*

Osmia (Melanosmia) gaudiosa Cockerell, 1907

Osmia (Melanosmia) indeprensa Sandhouse, 1939^*

Osmia (Osmia) ribifloris Cockerell, 1900

Osmia (Melanosmia) tarsata Provancher, 1888

Stelis (Stelis) interrupta Cresson, 1879

Melittidae

Hesperapis (Carinapis) carinata Stevens, 1919

Macropis (Macropis) nuda (Provancher, 1882)

Records excluded from analysis

We highlight 38 records as questionable and propose that they require more research to confirm their presence in Washington state. Many of these would be significant and surprising range expansions. Most of these records were obtained from data made available through GBIF, Discover Life, or BOLD, and could represent species that are mislabeled or misidentified in their parent collections. A few records were derived from identifications recorded in older revisions and may reflect outdated taxonomy. We do not include these records in the total bees recorded by state or county and highlight them here to ensure they are treated with appropriate caution.

Andrenidae

1. ! Andrena (Andrena) mandibularis Robertson, 1892 – Yakima^2,3; Apr^2,3 (1987^2,3); INHS

Comments. This species is generally eastern in distribution.

2. ! Andrena (Andrena) tridens Robertson, 1902 – Kittitas ^2,3; May^2,3 (1989^2,3); INHS

Comments. This species is generally eastern in distribution.

3. ! Andrena (Cnemidandrena) luteihirta Donovan, 1977 – Benton ⁷; Jul⁷ (1994⁷); WSUC

Comments. This species is generally restricted to southern California, west of the Sierra Nevada mountains. A positive identification requires examination of genitalia; this specimen (which is a male with the genitalia hidden) is more likely the closely related A. surda which occurs east and north of the Sierra Nevada range.

4. ! Andrena (Conandrena) cheyennorum Viereck and Cockerell, 1914 – Whitman ^2,3; (2003^2,3); BBSL

Comments. This species is generally southwestern in distribution

5. ! Andrena (Melandrena) sayi Robertson, 1891 – Snohomish ^1,3; Aug^1,3 (1985^1,3); INHS

Comments. This species is generally eastern in distribution.

6. ! Andrena (Onagrandrena) rozeni Linsley and MacSwain, 1955 – King ^2,3; May^2,3 (1914^2,3); INHS

Comments. This species is generally southwestern in distribution.

7. ! Andrena (Ptilandrena) erigeniae Robertson, 1891 – Kittitas ^2,3; Apr^2,3 (1989^2,3); INHS

Comments. This species is generally eastern in distribution.

8. ! Calliopsis (Nomadopsis) obscurella Cresson, 1879 – Franklin¹¹⁸; May¹¹⁸ (1896¹¹⁸)

Comments. Older identification - Rozen (1958) recommends these records be taken with caution until the specimens have either been examined or other records in the distributional gap are confirmed.

9. ! Perdita (Perdita) aridella Timberlake, 1960 – Benton ^1,2; May^1,2, Jun^1,2, Aug^1,2 (2015^1,2); BBSL

Comments. This species is generally southwestern in distribution.

10. ! Perdita (Perdita) ashmeadi Cockerell, 1899 – Columbia ^1,2,4; PCYU

Comments. This species is generally southwestern in distribution. Additionally, P. ashmeadi is a specialist on Prosopis spp. (Simpson and Neff 1987) which do not occur in Washington state.

Apidae

11. ! Anthophora (Clisodon) furcata (Panzer, 1798) – Grays Harbor ^1,2, Pierce^1,2; Jul^1,2 (1935^1,2); SEMC

Comments. This species is generally European in distribution. However, A. terminalis was sometimes considered a subspecies of A. furcata (Muesebeck et al. 1951; Hurd 1979) and sometimes a full species (Mitchell 1962). These records are likely older identifications of A. terminalis.

12. ! Anthophorula (Anthophorula) rufiventris (Timberlake, 1947) – no location reported^2,4; PCYU

Comments. This species is generally southwestern in distribution.

13. ! Bombus (Alpinobombus) polaris Curtis, 1835 – Thurston ^1,2, Yakima^1,2; Jul^1,2, Aug^1,2 (1971^1,2); NMNH; Data Deficient (Hatfield et al. 2016b)

Comments. This species is generally arctic in distribution.

14. ! Bombus (Bombus) terricola Kirby, 1837 – San Juan^1,2,3, Whitman^1,2, Yakima^1,2; May^1,2,3, Aug^1,2 (1959^1,2); INHS, PMNH; Vulnerable (National Research Council 2007; Hatfield et al. 2015c); G3 – Vulnerable globally (NatureServe 2024)

Comments. Milliron (1971) considered Bombus occidentalis a subspecies of B. terricola; however, current taxonomy classifies B. occidentalis as a distinct species (e.g., Bertsch et al. 2010; Williams et al. 2012; Owen and Whidden 2013). It is probable that these records represent B. occidentalis.

15. ! Bombus (Psithyrus) ashtoni (Cresson, 1864) – Whitman ^1,2,3; Oct^1,2,3 (1960^1,2,3); BBSL; Data Deficient (Hatfield et al. 2016c); G4 – Apparently Secure globally (NatureServe 2024)

Comments. This species is generally northern and eastern in distribution.

16. ! Bombus (Pyrobombus) ternarius Say, 1837 – Whitman ¹; Oct¹ (1950¹); PSUC; Least Concern (Hatfield et al. 2014i)

Comments. This species is generally northeastern and northcentral in distribution.

17. ! Bombus (Subterraneobombus) borealis Kirby, 1837 – Clallam ^1,2,3; Sep^1,2,3 (1955^1,2,3); CNC; Least Concern (Hatfield et al. 2015o)

Comments. This species is generally northeastern and northcentral in distribution.

18. ! Bombus (Thoracobombus) pensylvanicus (DeGeer, 1773) – Mason ^1,2,3, Thurston^1,2,3; Aug^1,2,3 (1908^1,2,3); BBSL; Vulnerable (Hatfield et al. 2015q)

Comments. This species is generally eastern and southwestern in distribution.

19. ! Habropoda depressa Fowler, 1899 – Walla Walla ^1,2; May^1,2 (1937^1,2); SEMC; G4 – Apparently Secure globally (NatureServe 2024)

Comments. This species is generally southwestern in distribution.

20. ! Melissodes (Eumelissodes) bicoloratus LaBerge, 1961 – Benton ^1,2; Jun^1,2 (2014^1,2); BBSL

Comments. This species is generally southwestern in distribution.

21. ! Melissodes (Eumelissodes) druriellus (Kirby, 1802) [= Melissodes rustica (Say, 1837)] – Benton^1,2; Jun^1,2 (2014^1,2); BBSL

Comments. This species is generally eastern and midwestern in distribution.

22. ! Melissodes (Eumelissodes) utahensis LaBerge, 1961 – Yakima ^2,3; Sep^2,3 (1993^2,3); INHS

Comments. This species is generally southwestern in distribution.

23. ! Nomada argentea (Schwarz, 1966) – Walla Walla^1,2,3; Jun^1,2,3 (1951^1,2); BBSL

Comments. This species is Middle Eastern in distribution.

24. ! Triepeolus lunatus (Say, 1824) – Klickitat^1,2; Aug^1,2 (2011^1,2); BBSL

Comments. This species is generally eastern and midwestern in distribution.

25. ! Triepeolus verbesinae (Cockerell, 1897) – Klickitat^1,2, Stevens³; Jul³, Sep^1,2 (2011^1,2); BBSL, NMNH

Comments. This species is generally southwestern in distribution.

Halictidae

26. ! Agapostemon (Agapostemon) sericeus (Forster, 1771) [= Agapostemon radiatus Say, 1837] – Douglas^1,2, Franklin¹¹⁹; May^1,2 (1905^1,2); FMNH

Comments. This species is normally distributed east of the Rocky Mountains.

27. ! Augochloropsis (Paraugochloropsis) sumptuosa (Smith, 1853) – Spokane ^1,2,3; Jun^1,2, Jul^1,2 (2007^1,2,3); BBSL

Comments. This species is generally eastern and midwestern in distribution.

28. ! Halictus (Nealictus) parallelus Say, 1837 – Kittitas ^1,2; Aug^1,2 (1967^1,2); FMNH

Comments. This species is generally eastern and midwestern in distribution.

Megachilidae

29. ! Anthidium (Anthidium) collectum Huard, 1896 – G3 – Vulnerable globally (NatureServe 2024)

Comments. Gonzalez and Griswold (2013) make note of an isolated record from south central Washington well outside the expected distribution, but do not provide a specific locality.

30. ! Coelioxys (Boreocoelioxys) insita Cresson, 1872 – Columbia^1,2,4; PCYU

Comments. This species is generally midwestern in distribution.

31. ! Dianthidium (Dianthidium) dubium H. F. Schwarz, 1928 – Spokane ^1,2; Jun^1,2, Jul^1,2 (2015^1,2); BBSL

Comments. This species is generally southwestern in distribution.

31a. ! Dianthidium (Dianthidium) dubium mccrackenae Timberlake, 1943 – Benton ^1,2, Walla Walla^1,2; Jun^1,2, Jul^1,2 (2014^1,2); BBSL

Comments. This subspecies is generally southwestern in distribution.

32. ! Hoplitis (Hoplitis) samarkanda (Warncke, 1991) – Garfield^1,2,3; (1998^1,2,3); BBSL

Comments. This species is generally Palearctic in distribution.

33. ! Megachile (Xanthosarus) latimanus Say, 1823 [= Megachile vidua Smith, 1853] – San Juan²⁴, Thurston²⁴, Whitman^1,2, Yakima^1,2; Jul^1,2,24, Aug²⁴ (1949^1,2); CMNH, MCZ; G5 – Secure globally (NatureServe 2024)

Comments. This species is generally only found east of the 100^th meridian. Megachile latimanus and M. perihirta are considered an eastern and western sibling pair with only subtle characters distinguishing M. latimanus females from M. perihirta females.

34. ! Osmia (Diceratosmia) subfasciata Cresson, 1872 – King ^1,2,3; Jul^1,2,3 (1929^1,2,3); BBSL; G5 – Secure globally (NatureServe 2024); LAMIACEAE: Prunella vulgaris³

Comments. This species is generally southern in distribution.

35. ! Osmia (Melanosmia) crassa Rust and Bohart, 1986 – Walla Walla ^1,2,3; May^1,2,3 (1937^1,2,3); BBSL

Comments. This species is generally southwestern in distribution.

36. ! Osmia (Melanosmia) granulosa Cockerell, 1911 – Walla Walla ^2,3; May^2,3 (1937^2,3); BBSL; G4 – Apparently Secure globally (NatureServe 2024)

Comments. Hurd (1979) synonymized O. granulosa with O. exigua without explanation. As this record and a single record from Wyoming are the only records of O. granulosa outside of California, NatureServe (2024) suggests that these records could possibly be O. exigua.

37. ! Osmia (Melanosmia) phenax Cockerell, 1897 [= Osmia titusi Cockerell, 1905] – Stevens^1,2; Jun^1,2, Jul^1,2 (2015^1,2); BBSL

Comments. This species is generally southwestern in distribution.

38. ! Stelis (Stelis) robertsoni Timberlake, 1941 – Spokane ¹; Jul¹ (2015¹); BBSL

Comments. This species is generally southwestern in distribution.

Acknowledgements

We are grateful to Dr. Katie Buckley, Dr. Karen Wright, and the Washington State Pollinator program for ongoing support and input. We thank Nate Green, Dr. Thor Hansen, and Dr. Julie Combs for the use of records from their personal collections, and the National Park Service for the use of records from their data. We recognize Dr. Richard Zack, Curator at the WSUC, for the decades of effort in surveys of the state of Washington. His work has added many county records from the Hanford site in Benton County. We also thank Dr. Julie Combs and Dr. Jack Neff for suggestions on this manuscript. Funding for this work was provided by the Washington State Legislature as part of SSB 5253 and from NSF DBI-2216934 to EAM.

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Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2014d) Bombus centralis. The IUCN Red List of Threatened Species 2014: e.T44937777A69001290. https://doi.org/10.2305/IUCN.UK.2014-3.RLTS.T44937777A69001290.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2014e) Bombus frigidus. The IUCN Red List of Threatened Species 2014: e.T44937790A69002715. https://doi.org/10.2305/IUCN.UK.2014-3.RLTS.T44937790A69002715.en

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Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2014g) Bombus melanopygus. The IUCN Red List of Threatened Species 2014: e.T44937809A68983638. https://doi.org/10.2305/IUCN.UK.2014-3.RLTS.T44937809A68983638.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2014h) Bombus mixtus. The IUCN Red List of Threatened Species 2014: e.T44937898A69004061. https://doi.org/10.2305/IUCN.UK.2014-3.RLTS.T44937898A69004061.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2014i) Bombus ternarius. The IUCN Red List of Threatened Species 2014: e.T44937988A69005644. https://doi.org/10.2305/IUCN.UK.2014-3.RLTS.T44937988A69005644.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015a) Bombus nevadensis. The IUCN Red List of Threatened Species 2015: e.T21215146A21215273. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T21215146A21215273.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S, Foltz Jordan S (2015b) Bombus occidentalis. The IUCN Red List of Threatened Species 2015: e.T44937492A46440201. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937492A46440201.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015c) Bombus terricola. The IUCN Red List of Threatened Species 2015: e.T44937505A46440206. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937505A46440206.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015d) Bombus griseocollis. The IUCN Red List of Threatened Species 2015: e.T44937645A46440221. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937645A46440221.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015e) Bombus rufocinctus. The IUCN Red List of Threatened Species 2015: e.T21215145A21215305. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T21215145A21215305.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015f) Bombus suckleyi. The IUCN Red List of Threatened Species 2015: e.T44937699A46440241. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937699A46440241.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015g) Bombus flavifrons. The IUCN Red List of Threatened Species 2015: e.T44937784A46440266. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937784A46440266.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015h) Bombus huntii. The IUCN Red List of Threatened Species 2015: e.T21215139A21215245. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T21215139A21215245.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015i) Bombus sitkensis. The IUCN Red List of Threatened Species 2015: e.T44937938A46440301. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937938A46440301.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015j) Bombus sylvicola. The IUCN Red List of Threatened Species 2015: e.T44937945A46440306. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937945A46440306.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015k) Bombus vagans. The IUCN Red List of Threatened Species 2015: e.T44938024A46440316. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44938024A46440316.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015l) Bombus vandykei. The IUCN Red List of Threatened Species 2015: e.T44938052A46440321. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44938052A46440321.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015m) Bombus vosnesenskii. The IUCN Red List of Threatened Species 2015: e.T44938235A46440326. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44938235A46440326.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015n) Bombus appositus. The IUCN Red List of Threatened Species 2015: e.T44938356A46440331. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44938356A46440331.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2015o) Bombus borealis. The IUCN Red List of Threatened Species 2015: e.T44938377A46440336. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44938377A46440336.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S, Foltz Jordan S (2015p) Bombus fervidus. The IUCN Red List of Threatened Species 2015: e.T21215132A21215225. https://doi.org/10.2305/IUCN.UK.2015-4.RLTS.T21215132A21215225.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S, Foltz Jordan S (2015q) Bombus pensylvanicus. The IUCN Red List of Threatened Species 2015: e.T21215172A21215281. https://doi.org/10.2305/IUCN.UK.2015-4.RLTS.T21215172A21215281.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S, Foltz Jordan S (2016a) Bombus kirbiellus. The IUCN Red List of Threatened Species 2016: e.T88088737A88291693. https://doi.org/10.2305/IUCN.UK.2016-1.RLTS.T88088737A88291693.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S, Foltz Jordan S (2016b) Bombus polaris. The IUCN Red List of Threatened Species 2016: e.T88120725A46440181. https://doi.org/10.2305/IUCN.UK.2016-1.RLTS.T88120725A46440181.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2016c) Bombus bohemicus. The IUCN Red List of Threatened Species 2016: e.T13152926A46440141. https://doi.org/10.2305/IUCN.UK.2016-1.RLTS.T13152926A46440141.en

Hatfield R, Jepsen S, Thorp R, Richardson L, Colla S (2016d) Bombus flavidus. The IUCN Red List of Threatened Species 2016: e.T13340361A46440156. https://doi.org/10.2305/IUCN.UK.2016-1.RLTS.T13340361A46440156.en

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1 We are aware of unpublished records for these species in Washington which could not be included in this checklist.

2 Mayer et al. (2000) states that their Moscow Mountain site is located in southeastern Washington; however, further investigation revealed that the Moscow Mountain site may, in fact, be located across the border in Idaho.

3 Discover Life has synonymized these species with other species already in the checklist without reference or explanation. As we are not aware of any publications that synonymize these species, these species are kept separate here.

4 Sheffield et al. (2011) raised Megachile lippiae from a subspecies of Megachile texana. It is possible records of M. lippiae in Washington already exist under the name M. texana.

Supplementary materials

Supplementary material 1

Life history data for each species

Chanda S. Bartholomew, Elizabeth A. Murray, Silas Bossert, Joel Gardner, Chris Looney

Data type: xlsx

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.

Download file (49.15 kb)

Supplementary material 2

Species by ecoregion

Chanda S. Bartholomew, Elizabeth A. Murray, Silas Bossert, Joel Gardner, Chris Looney

Data type: csv

Download file (20.97 kb)

﻿Abstract

Keywords

﻿﻿Introduction

﻿﻿Materials and methods

﻿﻿Results and discussion

﻿﻿Checklist

﻿﻿Andrenidae: Andreninae: Andrenini

﻿﻿Genus Andrena Fabricius

﻿﻿Panurginae: Calliopsini

﻿﻿Genus Calliopsis Smith

﻿﻿Panurgini

﻿﻿Genus Panurginus Nylander

﻿﻿Perditini

﻿﻿Genus Perdita Smith

﻿﻿Apidae: Anthophorinae: Anthophorini

﻿﻿Genus Anthophora Latreille

﻿﻿Genus Habropoda Smith

﻿﻿Apinae: Apini

﻿﻿Genus Apis Linnaeus

﻿﻿Bombini

﻿﻿Genus Bombus Latreille

﻿﻿Eucerinae: Emphorini

﻿﻿Genus Diadasia Patton

﻿﻿Eucerini

﻿﻿Genus Epimelissodes Ashmead

﻿﻿Genus Eucera Scopoli

﻿﻿Genus Melissodes Latreille

﻿﻿Nomadinae: Ammobatini

﻿﻿Genus Oreopasites Cockerell

﻿﻿Epeolini

﻿﻿Genus Epeolus Latreille

﻿﻿Genus Triepeolus Robertson

﻿﻿Melectini

﻿﻿Genus Brachymelecta Linsley

﻿﻿Genus Melecta Latreille

﻿﻿Genus Zacosmia Ashmead

﻿﻿Nomadini

﻿﻿Genus Nomada Scopoli

﻿﻿Xylocopinae: Ceratinini

﻿﻿Genus Ceratina Latreille

﻿﻿Xylocopini

﻿﻿Genus Xylocopa Latreille

﻿﻿Colletidae: Colletinae: Colletini

﻿﻿Genus Colletes Latreille

﻿﻿Hylaeinae: Hylaeini

﻿﻿Genus Hylaeus Fabricius

﻿﻿Halictidae: Halictinae: Halictini

﻿﻿Genus Agapostemon Guerin-Meneville

﻿﻿Genus Halictus Latreille

﻿﻿Genus Lasioglossum Curtis

﻿﻿Genus Sphecodes Latreille

﻿﻿Nomiinae: Nominiini

﻿﻿Genus Nomia Latreille

﻿﻿Rophitinae

﻿﻿Genus Dufourea Lepeletier

﻿﻿Megachilidae: Megachilinae: Anthidiini

﻿﻿Genus Anthidiellum Cockerell

﻿﻿Genus Anthidium Fabricius

﻿﻿Genus Dianthidium Cockerell

﻿﻿Genus Stelis Panzer

﻿﻿Dioxyini

﻿﻿Genus Dioxys Lepeletier and Serville

﻿﻿Megachilini

﻿﻿Genus Coelioxys Latreille

﻿﻿Genus Megachile Latreille

﻿﻿Osmiini

﻿﻿Genus Ashmeadiella Cockerell

﻿﻿Genus Atoposmia Cockerell

﻿﻿Genus Chelostoma Latreille

﻿﻿Genus Heriades Spinola

﻿﻿Genus Hoplitis Klug

﻿﻿Genus Osmia Panzer

﻿﻿Genus Protosmia Ducke

﻿﻿Melittidae: Melittinae: Macropidini

﻿﻿Genus Macropis Panzer

﻿﻿Bee species likely to occur in Washington

﻿﻿Andrenidae

﻿﻿Apidae

﻿﻿Halictidae

﻿﻿Megachilidae

Abstract

Introduction

Materials and methods

Results and discussion

Checklist

Andrenidae: Andreninae: Andrenini

Genus Andrena Fabricius

Panurginae: Calliopsini

Genus Calliopsis Smith

Panurgini

Genus Panurginus Nylander

Perditini

Genus Perdita Smith

Apidae: Anthophorinae: Anthophorini

Genus Anthophora Latreille

Genus Habropoda Smith

Apinae: Apini

Genus Apis Linnaeus

Bombini

Genus Bombus Latreille

Eucerinae: Emphorini

Genus Diadasia Patton

Eucerini

Genus Epimelissodes Ashmead

Genus Eucera Scopoli

Genus Melissodes Latreille

Nomadinae: Ammobatini

Genus Oreopasites Cockerell

Epeolini

Genus Epeolus Latreille

Genus Triepeolus Robertson

Melectini

Genus Brachymelecta Linsley

Genus Melecta Latreille

Genus Zacosmia Ashmead

Nomadini

Genus Nomada Scopoli

Xylocopinae: Ceratinini

Genus Ceratina Latreille

Xylocopini

Genus Xylocopa Latreille

Colletidae: Colletinae: Colletini

Genus Colletes Latreille

Hylaeinae: Hylaeini

Genus Hylaeus Fabricius

Halictidae: Halictinae: Halictini

Genus Agapostemon Guerin-Meneville

Genus Halictus Latreille

Genus Lasioglossum Curtis

Genus Sphecodes Latreille

Nomiinae: Nominiini

Genus Nomia Latreille

Rophitinae

Genus Dufourea Lepeletier

Megachilidae: Megachilinae: Anthidiini

Genus Anthidiellum Cockerell

Genus Anthidium Fabricius

Genus Dianthidium Cockerell

Genus Stelis Panzer

Dioxyini

Genus Dioxys Lepeletier and Serville

Megachilini

Genus Coelioxys Latreille

Genus Megachile Latreille

Osmiini

Genus Ashmeadiella Cockerell

Genus Atoposmia Cockerell

Genus Chelostoma Latreille

Genus Heriades Spinola

Genus Hoplitis Klug

Genus Osmia Panzer

Genus Protosmia Ducke

Melittidae: Melittinae: Macropidini

Genus Macropis Panzer

Bee species likely to occur in Washington

Andrenidae

Apidae

Halictidae

Megachilidae

Melittidae