Corresponding author: Lynn S. Kimsey (
Academic editor: Wojciech Pulawski
The species of paper wasps in the tribe
Vespinae, or the yellow jackets and hornets, are among the most recognizable wasps in North America. All of the species are either social or are social parasites of other congeners. They construct their nests out of a mixture of plant fibers and salivary secretions, and the nests can range from baseball-sized, with a few thousand cells, to nests with hundreds of thousands of cells. Nests are generally annual but a few species will develop large perennial nests in warm climates. A number of species, such as
There have been a number of changes in the North American social vespine fauna since the widely used key published by
Given these changes, and the difficulty of using many of the existing keys, which rely heavily on coloration, we have developed a new key incorporating these taxonomic changes and attempting to place more emphasis on structural features, such as male genitalia. The key by
North America as construed here is America north of Mexico. Thus two species recently described from central Mexico (
Specimens used in the development of this key were from the collections of the American Museum of Natural History, New York; Bohart Museum of Entomology, University of California, Davis; California State Collection of Arthropods, California Department of Food & Agriculture, Sacramento, and the U. S. National Museum of Natural History, Washington, D. C.
Type repositories listed in the synonymies include: BUDAPEST – Hungarian Natural History Museum, Budapest; CAMBRIDGE – Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA; COPENHAGEN – Zoologisk Museum, Universitetsparken, Copenhagen, Denmark; DRESDEN – Staatliches Museum für Tierkunde, Dresden, Germany; GAINESVILLE – Florida State Collection of Arthropods, Gainesville, USA; GENEVA – Museum of Natural History, Geneva, Switzerland; GENOA – Museo Civico di Storia Naturale “Giacomo Doria”, Génova, Italy; LEIDEN – Rijksmuseum van Natuurlijke Historie, Leiden, Netherlands; LINNAEAN SOCIETY – Linnaean Society, London, UK; LONDON – The Museum of Natural History, London, UK; OTTAWA – Canadian National Collection of Insects, Agriculture Canada, Ottawa; OXFORD – Hope Entomological Collections, Oxford University, England; PARIS – Muséum National d’Histoire Naturelle, Paris, France; PHILADELPHIA – Academy of Natural Sciences, Philadelphia, Pennsylvania, USA; ST. PETERSBURG – Zoological Institute, St. Petersburg, Russia; STOCKHOLM – Naturhistoriska Riksmuseet, Stockholm, Sweden; TAICHUNG – National Museum of Natural Sciences, Taichung, Taiwan; TURIN – Instituto di Zoologia Sistematica, Universita di Torino, Turin, Italy; UPPSALA – Uppsala University Zoological Museum, Uppsala, Sweden; WASHINGTON - U. S. Museum of Natural History, Washington, D. C., USA.
1 | Head in dorsal view greatly expanded behind eyes, postocular distance more than twice as broad as distance between hindocelli (as in |
2 |
– | Head in dorsal view not expanded behind eyes, postocular distance subequal to distance between hindocelli (as in |
4 |
2 | Metasomal segments I and II orange or red, posterior segments black, without sublateral free or connected blackish spots ( |
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– | Metasomal segments basally blackish to brown and apically yellow; metapleural punctures ventrally shallow, separated by 1 puncture diameter or more | 3 |
3 | Female clypeal punctures clearly defined, contiguous or nearly so; male metasomal sterna VI-VII apicomedial margin straight or shallowly indented; metasomal terga III–VI transverse basal black band with sublateral free or connected black spot ( |
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– | Female clypeal punctures medially, shallow, separated by 1 puncture diameter or more; male metasomal sterna VI-VII apicomedial margin deeply emarginate; metasomal terga III transverse basal black band simple, barely undulating ( |
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4 | Malar space long, one fifth eye height or longer ( |
5 |
– | Malar space short, one-tenth eye height ( |
10 |
5 | Metasomal terga I-III entirely black ( |
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– | Metasomal terga I-III with pale markings; pronotal lateral angle not rugose | 6 |
6 | Occipital carina absent; female clypeal apical margin acutely angulate; male apical flagellomeres without tyloids; Alaska to Newfoundland, south to Arizona, North Carolina, Georgia | |
– | Occipital carina present; female clypeal apical margin with obtuse to right angles; male apical flagellomeres with tyloids | 7 |
7 | Body, particularly face, with whitish markings, metasomal terga I-II often with lateral red spots ( |
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– | Body, particularly face, with yellow markings, usually without red metasomal spots; more southern distribution | 8 |
8 | Metasomal terga I and II broad yellow bands expanded medially into sharp, triangular projection ( |
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– | Metasomal terga I and II with narrow, parallel-sided yellow bands, sometimes slightly narrowed medially; genal band integrity variable | 9 |
9 | Malar space length one-fourth eye height; clypeal apex width 1.5–1.6× malar space length; male apical flagellomeres with two tyloids; Alaska to Newfoundland, south to Colorado, Georgia | |
– | Malar space length one-fifth eye height; clypeal apex width 1.9–2.0× malar space length; male apical flagellomeres with one or two tyloids; western North America, Alaska and Alberta south to Arizona | |
10 | Female; six metasomal segments; 10 flagellomeres | 11 |
– | Male, seven metasomal segments; 11 flagellomeres | 23 |
11 | Scutum with two fully developed longitudinal yellow stripes (as in |
12 |
– | Scutum without stripes, if stripes present only partly developed; metasomal sterna with extensive black markings | 13 |
12 | Metasomal terga II-IV with small oval sublateral black spots ( |
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– | Metasomal terga II-IV without small oval sublateral black spots ( |
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13 | Pale body markings whitish; metasomal tergum II pale apical band narrow and parallel-sided (as in |
14 |
– | Body markings yellow; metasomal tergum II pale apical band usually broad and sinuous or emarginated medially (as in |
15 |
14 | Metasomal terga I and II with reddish markings, tergum I extensively red, with posterior whitish band along apical margin, usually with partial transverse whitish band at apex of anterior face ( |
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– | Metasomal terga I and II without reddish markings; tergum I black, with partial white band along posterior margin and often partial white band at apex of anterior face ( |
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15 | Eye dorsally margined by continuous yellow band ( |
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– | Eye not dorsally margined by yellow band on (as in |
16 |
16 | Hindtibia with long black setae; clypeal apical angles acute in females ( |
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– | Hindtibia without long black setae; clypeal apical angles blunt in females (as in |
17 |
17 | Scape yellow ventrally | 18 |
– | Scape without yellow ventrally, although may be dark brown ventrally | 20 |
18 | Metasomal tergum II largely black, irregularly parallel-sided, with narrow apical yellow band and without sublateral yellow spot or spot faint ( |
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– | Metasomal tergum II black band apically lobate, with broad apical yellow band as broad or broader than apical bands on III-V, and usually with sublateral yellow spot (as in |
19 |
19 | Metasomal tergum II black band angulate medially; gena with continuous yellow band in side view, sometimes interrupted by black spot or narrow medial interruption ( |
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– | Metasomal tergum II black band broadly rounded medially, often having free lateral yellow spots; gena with yellow band broadly interrupted by black spot, rarely continuous ( |
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20 | Supraantennal black band as broad or broader than antennal socket; gena with yellow band broadly interrupted by black spot in side view | |
– | Supraantennal black band much narrower than antennal socket; gena with yellow band uninterrupted or narrowly broken in side view | 21 |
21 | Metasomal tergum I with diamond-shaped or somewhat broader medial black mark, attachment to anterior black band no narrower than one-third of width ( |
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– | Metasomal tergum I with nearly free broadly diamond-shaped or triangular black mark or black mark broadly attached to anterior band | 22 |
22 | Metasomal tergum I with anchor-shaped medial black mark, narrowly connected to anterior black band, if melanistic with at least pair of transverse yellow spots present ( |
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– | Metasomal tergum I with triangular medial black mark, broadly connected to anterior black band ( |
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23 | Paramere dorsomedial margin evenly convex, without well-developed acute tooth or angle (as in |
24 |
– | Paramere dorsomedial margin with well-developed tooth or angle (as in |
31 |
24 | Scutum with two longitudinal yellow stripes (as in |
25 |
– | Scutum without longitudinal yellow stripes | 26 |
25 | Aedeagus elongate, strongly exserted beyond apex of paramere by one-half of paramere length or longer (as in |
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– | Aedeagus short, broad, exserted beyond apex of paramere by one-third of paramere length or less ( |
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26 | Body with pale markings whitish | 27 |
– | Body with pale markings yellow | 28 |
27 | Basal metasomal segments without red markings ( |
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– | Basal metasomal segments with red markings ( |
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28 | Metasomal tergum I with diamond-shaped medial black mark, tergum II with broad irregularly lobate posterior yellow band ( |
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– | Metasomal terga I and II with narrow subparallel-sided posterior yellow band (as in |
29 |
29 | Clypeus with large medial black spot or stripe ( |
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– | Clypeus without single medial black spot or black spot small irregular (as in |
30 |
30 | Hindtibia without long black setae; clypeal apical angle obtusely angulate | |
– | Hindtibia with long black setae (even rubbed specimens have a few); clypeal apical angle blunt but well-developed ( |
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31 | Metasomal tergum I with diamond shaped medial black mark narrowly connected to black band (as in |
32 |
– | Metasomal tergum I with parallel-sided black band, black band with triangular medial projection, broadly attached to rest of band (as in |
34 |
32 | Aedeagus without lobe or process behind apex ( |
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– | Aedeagus with short rounded ( |
3 |
33 | Metasomal tergum VII undulate, rounded dorsally in lateral view ( |
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– | Metasomal tergum VII step-like in lateral view, angulate dorsally in lateral view ( |
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34 | Supraantennal black band much narrower than antennal socket at least medially; metasomal terga II-V with strongly trilobate black band ( |
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– | Supraantennal black band as wide or wider than antennal socket; metasomal terga II-V with black band parallel-sided or weakly lobate ( |
This species occurs in the Hudsonian Zone of North America from Alaska to Maine.
This is a northern boreal species found in western North America from Alaska to Alberta, and extending as far south as Arizona and New Mexico along the Rocky Mountains (R. Jacobson personal communication).
It occurs as far south as California, Arizona and Georgia in North America. Pale markings can be yellow or whitish in
This species is an obligatory social parasite of
This species is abundant throughout boreal North America.
The species occurs throughout North America.
This is the only
This species builds small, aerial nests.
Front view of face, antennae removed.
There is a single report of a colony of this Asian species in North America, from San Pedro, in Los Angeles Co., California in 2010 (LSK, personal observation). It is not clear if the species has become established in California. It has also been introduced into New Zealand. Its native range is from India to the Bismarck Islands.
In Asia,
The central European color form of this Palearctic species was introduced into the New York area in the mid-1800’s (de
Nests are generally built in above-ground cavities, wall voids, hollow trees, and even in abandoned honey bee hives. Nests are large in size because of the size of the wasps but generally contain only a few thousand cells. These wasps feed on live insects, including honey bees near hives (
This East Asian species was introduced into British Columbia, Canada but has apparently not become established. We have included it in this review because of the potential for a reintroduction.
Nests are built in a wide variety of situations including in bushes, underground cavities, hollow trees, under eaves, in attics, on rock walls, and in wall voids. As with the other
Dorsal view of worker metasoma.
Dorsal view of worker metasoma.
Lateral view of genital capsule in
This is primarily a boreal species, occurring across subArctic Canada and southern Alaska. Its range extends further south in the Rocky, Sierra, Cascade, Siskiyou and Appalachian mountains.
Widespread in North America
This North American species was usually known as
This species builds subterranean nests, preferring open areas, including pastures and golf courses. It is predatory on other insects.
This predatory species preys on live insects and usually nests in cavities, using sites in logs, wall voids and rodent burrows.
It builds subterranean nests. This species feeds on live insects, as well as other sources of sugar and protein, and is a scavenger much like
The nests are usually built in structures or less commonly in the ground. Nests can be huge and may become perennial in warmer climates. These wasps feed on live prey or scavenge any source of protein or sugar.
The distribution of
This is an obligatory social parasite of
These wasps occur in the far northern Nearctic Region.
The biology of North American
Although treated as a synonym of
This species is the most common
It builds subterranean nests in a wide variety of situations, even in abandoned vehicles. These yellow jackets prey on live insects and are also scavengers of sources of protein and sugar.
This is the most abundant pest species of
Nests are usually built in cavities, which may be in the ground or in structures, such as attics, wall voids and even basements. The nests can become huge and often become perennial in warmer climates. These wasps are general scavengers, and will feed on live prey or any other source of protein or sugar including garbage. It is adventive in Hawaii.
This is an eastern species, occurring east of the 100th meridian and south to Honduras.
It is a facultative social parasite of
This is the yellowest of the North American species, with a two yellow-striped scutum much like that seen in
Most nests are subterranean but
Lateral view of genital capsule in
Ventral view of genital capsule in
JMC acknowledges the support of National Science Foundation Grant DEB-0843505. The manuscript was greatly improved by comments and suggestions from Michael Archer and Bob Jacobson.