Research Article |
Corresponding author: Andreas Müller ( andreas.mueller@usys.ethz.ch ) Academic editor: Michael Ohl
© 2018 Andreas Müller, Christophe Praz, Achik Dorchin.
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:
Müller A, Praz C, Dorchin A (2018) Biology of Palaearctic Wainia bees of the subgenus Caposmia including a short review on snail shell nesting in osmiine bees (Hymenoptera, Megachilidae). Journal of Hymenoptera Research 65: 61-89. https://doi.org/10.3897/jhr.65.27704
|
Wainia, a species-poor genus of osmiine bees, contains two Palaearctic species, whose biologies are unknown. In the present publication, we describe the nesting site and nest architecture of W. sexsignata and analyse the pollen host spectra of W. sexsignata and W. eremoplana by microscopical analysis of larval faeces and female scopal contents. W. sexsignata nests in empty snail shells. It uses large petal pieces of yellow flowered Asteroideae to separate the linearly arranged brood cells and to construct a series of partitions between the outermost cell and the final nest closure, which consists of masticated green leaves. W. sexsignata is recorded as a new host of the meloid beetle Sitarobrachys thoracica. Both Palaearctic Wainia species have a strong preference for Asteraceae as pollen hosts, but occasionally also collect pollen on other plant taxa. A literature survey revealed that nesting in empty snail shells is widespread among osmiine bees: obligate snail shell nesting is assumed to have independently evolved at least twelve times in their evolutionary history and to occur in at least 56 species belonging to 4 genera and 14 subgenera.
Apiformes , Asteroideae , Carduoideae , desert, DNA barcoding, host plant preference, nesting behaviour, Sphincterochila
Wainia Tkalců is a species-poor genus of osmiine bees (Megachilidae, Osmiini) restricted to the eastern hemisphere and comprising 11 described species (
The biology of the two Palaearctic Wainia species is unknown. In contrast, five Afrotropical species were found or strongly supposed to nest in empty snail shells (
In the present contribution, we i) use DNA barcoding technique to prove that Wainia sexsignata did construct the putative Wainia nests from Morocco, ii) describe the nest of W. sexsignata and compare its architecture with that of the nests of Afrotropical W. (Caposmia) species, iii) analyse the pollen host preferences of both Palaearctic W. (Caposmia) species by microscopical pollen analysis of larval faeces and female scopal contents and iv) give a short review on snail shell nesting in osmiine bees.
Nests of snail shell nesting bees were collected 2.75 km southwest of Ifrane Atlas-Saghir (29°12.18'N, 09°30.32'W, 750m a.s.l.) in the province of Guelmim in southern Morocco on 17 April 2017. Ifrane Atlas-Saghir is characterized by an arid climate with a mean annual temperature of 17.3 °C and a mean annual precipitation of 170 mm (https://en.climate-data.org/location/715098). The two presumed nests of Wainia sexsignata were found on a stony and sparsely vegetated plain adjacent to a dry riverbed (Fig.
DNA barcoding was performed with one dead prepupa originating from one of the two snail shell nests and a leg of a female of Wainia sexsignata collected on 18 April 2017 near Sidi Ifni (29°15.13'N, 10°16.93'W), about 75 km from the site where the presumed Wainia nests had been found. DNA was extracted with a “NucleoSpin Tissue” kit (Macherey-Nagel) following the manufacturer’s protocol. The 658 base-pair-long barcoding fragment of the mitochondrial gene Cytochrome Oxidase I was amplified using the primers LepF and LepR (
To uncover the pollen host preferences of Wainia eremoplana, the scopal pollen contents of 50 females collected at 21 different localities in Israel and Palestine (n = 47), Jordan (n = 2) and Tunisia (n = 1) were microscopically analyzed applying the method outlined by
The description of the pollen collecting behaviour of Wainia eremoplana is based on field observations made in Jordan in the Wadi al Hasa south of Al-Karak (30°57.51'N, 35°45.50'E) on 20 April 2007.
The chromatograms obtained from both prepupa and adult of Wainia sexsignata were clean. Translations to amino acids revealed that none of the sequences contained stop codons. Blast searches on Genbank and identification requests on BOLD indicated that neither sequence appeared to be close (>90% similarity) to any previously published sequence. The closest matches (approximately 88% similarity) were to diverse osmiine bee taxa (no sequence of Wainia (Caposmia) is available for this mitochondrial fragment). Both sequences were nearly identical to each other and differed by a single nucleotide on position 214, corresponding to an uncorrected genetic distance of 0.18%. This single point mutation is in a third codon position and is silent. Consequently, even if both sequences are not 100% identical it can confidently be concluded that the analyzed prepupa belongs to W. sexsignata.
The two nests of W. sexsignata were already closed when they were discovered. Each nest was built in an empty snail shell of Sphincterochila sp. (Sphincterochilidae) with a maximal diameter of 19 mm (Figs
The brood cells were arranged in a linear series and had a length of 15–17 mm (Fig.
Wainia sexsignata. 4 Brood cell partition built from yellow petal pieces of Asteroideae, which are partly covered with dark brown remnants of the larval cocoon; note the portion of leaf pulp at the right upper side of the partition used to glue the petal pieces to the inner shell surface 5 Partition of the nest plug 6 Nest plug consisting of a series of four partitions constructed from yellow Asteroideae petal pieces immediately followed by the nest closure at the shell opening, which consists of leaf pulp; the partition at the extreme right is the outermost brood cell partition 7 Yellow petal pieces adhering to the rear side of the nest closure 8 Anterior part of the nest plug with an additional wall of leaf pulp built in front of the second outermost plug partition 9Asteroideae petal pieces used to construct cell and plug partitions; petals in the upper row with traces of leaf pulp, which glued them to the inner shell surface.
The nest plug, which occupied the space between the outermost cell partition and the shell opening, had a length of 9 mm and 11 mm, respectively. It consisted of four and six partitions, respectively (Fig.
The innermost brood cell of one nest harboured a pupa of the blister beetle Sitarobrachys thoracica (Kraatz) (Meloidae) encapsulated in the cast skins of its last larval instars. This species parasitizes brood cells of andrenid and megachilid bees (
The microscopical analysis of digested pollen grains in the larval faeces of Wainia sexsignata revealed that pollen of the Asteroideae (Asteraceae) was the near exclusive constituent of the former pollen provisions (Tab.
Wainia eremoplana is mesolectic on Asteraceae and Brassicaceae (Tab.
10 Asteriscus graveolens (Asteroideae, Asteraceae), an important pollen host of Wainia sexsignata (photo V. Mauss) 11 Female of Wainia eremoplana collecting pollen on Centaurea spec. (photo G. Pisanty) 12 Habitat of Wainia eremoplana in the central Negev Desert of Israel at Nahal Hatira (the large crater), 10 km east of Yeroham.
Pollen composition of larval faeces of Wainia sexsignata in two nests with three brood cells each.
Asteraceae, Asteroideae | Scrophulariaceae | Unknown | ||
---|---|---|---|---|
nest 1 | brood cell 1 | 100% | ||
brood cell 2 | 100% | |||
brood cell 3 | 100% | |||
nest 2 | brood cell 1 | 90% | 10% | |
brood cell 2 | 100% | |||
brood cell 3 | 90% | 10% |
Pollen composition of female pollen loads of Wainia eremoplana. n = 50 pollen loads from 21 different localities in Israel and Palestine (n = 47), Jordan (n = 2) and Tunisia (n = 1).
Plant family | Plant subfamily | % pollen grain volume | number of loads with this pollen type | number of pure loads |
---|---|---|---|---|
Asteraceae | 92.0 | 50 (100%) | 23 (46%) | |
Asteraceae | Asteroideae | 78.9 | 47 (94%) | 14 (28%) |
Asteraceae | Carduoideae | 12.4 | 13 (26%) | 2 (4%) |
Asteraceae | Cichorioideae | 0.7 | 1 (2%) | 0 (0%) |
Brassicaceae | 8.0 | 27 (54%) | 0 (0%) |
The use of large petal pieces to construct both cell and plug partitions and the presence of a series of partitions evenly distributed in the space between the outermost cell partition and the nest closure as observed in Wainia sexsignata are unique characteristics among the Palaearctic osmiine bees. Both characteristics, however, were also recorded in two snail shell nesting Afrotropical W. (Caposmia) species (
In contrast, the snail shell nests of the Afrotropical Wainia (Caposmia) elizabethae (Friese) substantially differ from those of the three W. (Caposmia) species addressed above (
Beside the four species discussed above, the South African Wainia (Caposmia) braunsi (Peters) was reared from snail shells (
Pollen analysis of larval faeces of Wainia sexsignata and female scopal contents of W. eremoplana revealed a strong affiliation of both species to the Asteraceae, particularly to the Asteroideae and to a lesser extent also to the Carduoideae. However, neither species is strictly oligolectic on Asteraceae. W. eremoplana regularly collects pollen also on Brassicaceae and pollen of Scrophulariaceae was recorded in the larval faeces of W. sexsignata. The finding that the larval faeces from four out of the six brood cells were exclusively composed of Asteroideae pollen indicates that the larvae of W. sexsignata are capable of developing on a pure Asteraceae pollen diet, thus being physiologically adapted to cope with the unfavourable properties of Asteraceae pollen, which has repeatedly been shown to hamper larval development of bee species not specialized on this plant family (
The pollen host preferences of the southern African Wainia (Caposmia) species have not been studied. Except for the observation of a single female of W. atrorufa visiting flowers of Hermannia (Malvaceae), no flower records exist (
Empty snail shells offer nesting opportunities for bees that build their brood cells within preexisting cavities. They appear to be well suited for nest construction for several reasons: i) the narrow and linear, albeit curved form of the shell cavity allows for the arrangement of the cells in a linear series and easy closure of the nest at the shell aperture; ii) the progeny are well protected by the considerable hardness of the shell and the usually white shell colour, which reflects the sunlight and thus might reduce the risk of overheating; iii) xeric habitats often harbour large numbers of empty snail shells providing numerous nesting opportunities; iv) the number of colonizable snail shells does not diminish over time due to the permanent renewal of the supply of dead shells; and v) the presence of empty snail shells enables colonization of habitats, e.g. (semi)arid areas, which naturally lack preexisting linear cavities such as insect burrows in dead wood or hollow plant stems used by innumerable bee species as nesting sites. On the other hand, nesting in exposed and movable snail shells may also entail disadvantages compared to nesting in the ground, in stems, in dead wood or in rock crevices: i) the larvae may have a higher risk of experiencing lethal temperatures by direct sunlight, particularly when they are still young and do not yet have reached the diapausing stage (see
Osmiine bee species recorded to nest in empty snail shells. Nea = Nearctic, Afr = Afrotropics, Pal = Palaearctic; obl = obligatory nesting in snail shells; fac = facultatively nesting in snail shells.
Species | Biogeo-graphic region | User type | Alternative nesting sites | References |
---|---|---|---|---|
Ashmeadiella (Ashmeadiella) spec. | Nea | ? | ? |
|
Hoplitis (Anthocopa) conchophila Kuhlmann | Afr | obl | – |
|
Hoplitis (Hoplitis) fertoni (Pérez) | Pal | obl | – |
|
Hoplitis (Hoplitis) pallicornis (Friese) | Pal | fac | holes in stones |
|
Hoplitis (Tkalcua) zandeni (Teunissen and van Achterberg) | Pal | obl | – |
|
Hoplitis (Tkalcua) spec. nov. | Pal | obl | – | A. Müller (unpublished data) |
Osmia (Allosmia) bischoffi Atanassov | Pal | obl | – |
|
Osmia (Allosmia) lhotelleriei Pérez | Pal | obl | – |
|
Osmia (Allosmia) melanura Morawitz | Pal | obl | – |
|
Osmia (Allosmia) rufohirta Latreille | Pal | obl | – |
|
Osmia (Allosmia) rutila Erichson | Pal | obl | – |
|
Osmia (Allosmia) sybarita Smith | Pal | obl | – |
|
Osmia (Diceratosmia) conjuncta Cresson | Nea | obl? | – |
|
Osmia (Diceratosmia) marilaunidii Cockerell | Nea | ? | ? |
|
Osmia (Diceratosmia) subfasciata Cresson | Nea | fac | insect burrows in dead wood; wooden trap nest blocks; hollow stems; abandoned cells of Sceliphron |
|
Osmia (Erythrosmia) andrenoides Spinola | Pal | obl | – |
|
Osmia (Helicosmia) aurulenta (Panzer) | Pal | obl | – |
|
Osmia (Helicosmia) clypearis acuta Warncke | Pal | ? | ? | A. Müller, C. Praz and C. Sedivy (unpublished data) |
Osmia (Helicosmia) melanogaster Spinola | Pal | fac | insect burrows in dead wood, hollow stems |
|
Osmia (Helicosmia) notata (Fabricius) | Pal | fac | cavities in stones, insect burrows in the ground |
|
Osmia (Helicosmia) orientalis Benoist | Pal | obl | – |
|
Osmia (Hoplosmia) carbo (Zanden) | Pal | obl | – |
|
Osmia (Hoplosmia) croatica Friese | Pal | obl | – |
|
Osmia (Hoplosmia) fallax Pérez | Pal | obl | – |
|
Osmia (Hoplosmia) pinguis Pérez | Pal | obl | – |
|
Osmia (Hoplosmia) spinigera Latreille | Pal | obl | – |
|
Osmia (Hoplosmia) spinulosa (Kirby) | Pal | obl | – |
|
Osmia (Neosmia) bicolor (Schrank) | Pal | obl | – |
|
Osmia (Neosmia) cinnabarina Pérez | Pal | obl | – | A. Müller (unpublished data) |
Osmia (Neosmia) jason Benoist | Pal | obl | – |
|
Osmia (Neosmia) rufigastra Lepeletier | Pal | obl | – |
|
Osmia (Neosmia) scutispina Gribodo | Pal | obl | – | C. Sedivy, C. Praz and A. Müller (unpublished data) |
Osmia (Neosmia) tingitana Benoist | Pal | obl | – |
|
Osmia (Osmia) bicornis (Linnaeus) | Pal | fac | wide spectrum of cavities of diverse form and size |
|
Osmia (Osmia) cornuta (Latreille) | Pal | fac | wide spectrum of cavities of diverse form and size |
|
Osmia (Osmia) tricornis Latreille | Pal | fac | insect burrows in dead wood; hollow stems; insect burrows in the ground |
|
Osmia (Pyrosmia) ferruginea Latreille | Pal | fac | hollow stems |
|
Osmia (Pyrosmia) gemmea Pérez | Pal | obl? | – |
|
Osmia (Pyrosmia) lobata Friese | Pal | ? | ? |
|
Osmia (Pyrosmia) versicolor Latreille | Pal | obl | – |
|
Osmia (Pyrosmia) viridana Morawitz | Pal | fac | holes in rocks; abandoned cells of Megachile (Chalicodoma) |
|
Protosmia (Protosmia) exenterata (Pérez) | Pal | obl? | – |
|
Protosmia (Protosmia) glutinosa (Giraud) | Pal | fac | abandoned cells of Anthophora, Megachile (Chalicodoma) and Sceliphron; cavities in the ground; insect burrows in the ground |
|
Protosmia (Protosmia) paradoxa (Friese) | Pal | obl? | – |
|
Protosmia (Protosmia) sideritis Tkalců | Pal | obl? | – |
|
Protosmia (Protosmia) stelidoides (Pérez) | Pal | obl? | – |
|
Protosmia (Protosmia) tauricola Popov | Pal | obl? | – | Banaszak and Romasenko (2001) |
Wainia (Caposmia) atrorufa (Friese) | Afr | obl | – |
|
Wainia (Caposmia) braunsi (Peters) | Afr | obl? | – |
|
Wainia (Caposmia) elizabethae (Friese) | Afr | obl | – |
|
Wainia (Caposmia) gessorum Kuhlmann | Afr | obl | – |
|
Wainia (Caposmia) sexsignata (Benoist) | Pal | obl | – | this study |
Records of snail shell nesting species exist for all three main bee taxa that occupy preexisting cavities as nesting sites, i.e. Megachilini, Anthidiini and Osmiini (Megachilidae). However, the proportion of snail shell nesters substantially differs among these three taxa. Snail shell nesting in the Megachilini appears to be almost absent. The only record of a snail shell nesting megachiline bee refers to the Palaearctic Megachile (Chalicodoma) lefebvrei (Lepeletier), which usually constructs its brood cells in holes of stones and rocks (
The snail shell nesting osmiine bees can be divided into two groups (Tab.
Based on available molecular phylogenies (
Phylogenetic distribution of snail shell nesting in osmiine bees. Red = taxa that probably exclusively consist of obligate snail shell nesters; blue = taxa that contain both obligate and facultative snail shell nesters (in Hoplitis (Anthocopa), only one (exclusive) snail shell nester is known); green = taxa that probably contain only facultative snail shell nesters; black = taxa that do not contain any snail shell nesters to the present knowledge (nesting biology of Hoplitis (Megahoplitis), Hoplitis (Platosmia), Wainia (Wainia), Wainia (Wainiella) and Osmia (Nasutosmia) still unknown). sp. gr. = species group. Phylogeny based on
Among the snail shell nesting osmiine bees, Osmia (Allosmia) and O. (Neosmia) are the only subgenera containing species that seal their nests with a mixture of leaf pulp and fragments of mollusc shells and that transport and bury their shells after nest closure (Tab.
Two species of Osmia (Allosmia), probably all species of O. (Neosmia) and one species of O. (Helicosmia) glue patches of leaf pulp onto the outer surface of the nest shell before and often also during cell construction and provisioning (Tab.
Species of Osmia (Allosmia) invariably construct only one brood cell per snail shell (Tab.
Several Palaearctic and Afrotropical species of the subgenera Osmia (Allosmia), O. (Erythrosmia), O. (Neosmia), O. (Pyrosmia) and Wainia (Caposmia) construct a barrier between the outermost cell partition and the nest closure, which most probably contributes to impede the invasion of the nests by predators and parasites (Fig.
14 Opened nest of Osmia (Helicosmia) notata with brood cells arranged side by side 15 Opened nest of Osmia (Hoplosmia) pinguis with brood cells arranged in a linear series 16 Nest of Osmia (Helicosmia) aurulenta densely covered with patches of leaf pulp 17 Opened nest of Hoplitis (Hoplitis) fertoni with brood cells arranged side by side (photo G. Le Goff) 18 Opened nest of Osmia (Allosmia) rufohirta with single brood cell (photo P. Westrich) 19 Opened nest of Osmia (Neosmia) bicolor with barrier composed of small pebbles and earth crumbs (photo A. Krebs).
One of the most fascinating aspects of the biology of snail shell nesting osmiine bees is the way the females treat their nests after having sealed them (Tab.
20Osmia (Pyrosmia) viridana at nest entrance (photo N. Vereecken) 21Protosmia (Protosmia) paradoxa on snail shell (photo N. Vereecken) 22Osmia (Hoplosmia) spinulosa turning its nest in situ 23Osmia (Allosmia) rufohirta rolling its nest towards a protected place 24Osmia (Allosmia) sybarita rolling its nest into a self excavated hole in sandy soil (photo N. Vereecken) 25Osmia (Neosmia) bicolor covering its nest with plant stalks (photo A. Krebs).
Nest characteristics of osmiine bee species recorded to nest in empty snail shells. For authors of the species names and references see Tab.
Species | Shell surface covered with patches of leaf pulp | Material used for brood cell partitions | Material used for nest plug | Number of brood cells | Arrangement of the cells | Treatment of the sealed shells |
---|---|---|---|---|---|---|
Ashmeadiella (Ashmeadiella) spec. | ? | ? | ? | ? | ? | ? |
Hoplitis (Anthocopa) conchophila | no | entire brood cells built from petal pieces | ? | up to 7 | linear | ? |
Hoplitis (Hoplitis) fertoni | no | mud, sometimes mixed with small pebbles | mud, sometimes mixed with small pebbles | 1-8 | linear and side by side | not moved |
Hoplitis (Hoplitis) pallicornis | ? | mud and small pebbles | ? | ? | ? | ? |
Hoplitis (Tkalcua) zandeni | no | mixture of leaf pulp and sand grains | mixture of leaf pulp and sand grains | 1-2 | linear | not moved |
Hoplitis (Tkalcua) spec. nov. | no | mixture of leaf pulp and sand grains | mixture of leaf pulp and sand grains | 1-2 | linear | not moved |
Osmia (Allosmia) bischoffi | yes | ? | ? | ? | ? | ? |
Osmia (Allosmia) lhotelleriei | no | leaf pulp | fragments of mollusc shells embedded into a matrix of leaf pulp | ? | ? | transported and buried |
Osmia (Allosmia) melanura | no | leaf pulp | fragments of mollusc shells embedded into a matrix of leaf pulp | 1 | - | transported and buried |
Osmia (Allosmia) rufohirta | yes | leaf pulp | layer of small pebbles and earth crumbs followed by a wall of leaf pulp | 1 | - | transported and hidden (rarely buried) |
Osmia (Allosmia) rutila | no | leaf pulp | fragments of mollusc shells, sometimes also small stones embedded into a matrix of leaf pulp | 1 | - | transported and buried |
Osmia (Allosmia) sybarita | no | leaf pulp | fragments of mollusc shells embedded into a matrix of leaf pulp | 1 | - | transported and buried or hidden |
Osmia (Diceratosmia) conjuncta | ? | leaf pulp | ? | ? | ? | ? |
Osmia (Diceratosmia) marilaunidii | ? | mixture of leaf pulp and sand | mixture of leaf pulp and sand | ? | ? | ? |
Osmia (Diceratosmia) subfasciata | ? | mixture of leaf pulp and sand or leaf pulp alone | mixture of leaf pulp and sand or leaf pulp alone | ? | ? | ? |
Osmia (Erythrosmia) andrenoides | no | leaf pulp | layer of loosely packed particles (small pebbles, earth crumbs and small plant sticks) followed by two walls of leaf pulp immediately behind each other | 1 | - | ? |
Osmia (Helicosmia) aurulenta | yes | leaf pulp | leaf pulp | up top 17 | linear and side by side | not moved |
Osmia (Helicosmia) clypearis acuta | ? | ? | leaf pulp | ? | ? | ? |
Osmia (Helicosmia) melanogaster | ? | leaf pulp | leaf pulp | several | ? | ? |
Osmia (Helicosmia) notata | no | leaf pulp | leaf pulp | up to 18 | linear and side by side | not moved |
Osmia (Helicosmia) orientalis | ? | leaf pulp | - | up to 10 | linear | ? |
Osmia (Hoplosmia) carbo | no | leaf pulp | leaf pulp | 1-3 | linear | not moved |
Osmia (Hoplosmia) croatica | no | leaf pulp | leaf pulp | 1 | - | ? |
Osmia (Hoplosmia) fallax | ? | ? | ? | 1-4 | ? | ? |
Osmia (Hoplosmia) pinguis | no | leaf pulp | leaf pulp | 2-4 | linear | not moved |
Osmia (Hoplosmia) spinigera | no | leaf pulp | leaf pulp | ? | ? | ? |
Osmia (Hoplosmia) spinulosa | no | leaf pulp | leaf pulp | 1-3 | linear | turned in situ |
Osmia (Neosmia) bicolor | yes | leaf pulp | layer of densely packed particles (small pebbles, earth crumps, broken mollusc shells, pieces of chalk and wood) followed by a wall of leaf pulp | 1-5 | linear | turned in situ, partly buried and covered |
Osmia (Neosmia) cinnabarina | yes | leaf pulp | layer of densely packed particles (small pebbles, fragments of mollusc shells, petals and stems) followed by a wall of leaf pulp with embedded fragments of mollusc shells and small pebbles | 1-3 | linear | ? |
Osmia (Neosmia) jason | yes | leaf pulp | four compartments each limited by walls made of leaf pulp; these compartments are either empty or filled with sand, earth crumps and small pebbles | 2 | linear | buried and covered |
Osmia (Neosmia) rufigastra | yes | leaf pulp | layer of densely packed particles (sand grains, earth crumbs, fragments of mollusc shells, stems and blades), followed by a wall of leaf pulp with embedded fragments of mollusc shells | 1 to several | linear | transported and buried |
Osmia (Neosmia) scutispina | yes | leaf pulp | layer of loosely packed particles (small pebbles, earth crumbs, leaflets or seeds) followed by a wall of leaf pulp | 6 | linear | ? |
Osmia (Neosmia) tingitana | yes | leaf pulp | layer of densely packed particles (sand grains, small pebbles, earth crumbs, fragments of mollusc shells and plants) followed by a wall of leaf pulp with embedded fragments of mollusc shells | 1-7 | linear | turned in situ and covered |
Osmia (Osmia) bicornis | ? | mud | mud | several | ? | ? |
Osmia (Osmia) cornuta | no | mud | mud | several | ? | ? |
Osmia (Osmia) tricornis | no | mud | mud | several | linear and side by side | not moved |
Osmia (Pyrosmia) ferruginea | no | leaf pulp | layer of loosely packed particles (small pebbles, earth crumbs, seeds or leaflets) followed by a wall of leaf pulp occasionally with embedded small pebbles or other particles | up to 10 | linear | not moved |
Osmia (Pyrosmia) gemmea | ? | ? | ? | ? | ? | ? |
Osmia (Pyrosmia) lobata | ? | leaf pulp | leaf pulp | 3 | linear | ? |
Osmia (Pyrosmia) versicolor | no | leaf pulp | layer of densely packed particles (small pebbles, earth crumbs, pieces of dry blades) followed by a wall of leaf pulp | up to 7 | linear | ? |
Osmia (Pyrosmia) viridana | no | leaf pulp mixed with small pebbles | layer of loosely packed particles (small pebbles, earth crumbs, pieces of dry blades) followed by a wall of leaf pulp mixed with small pebbles | several | linear | ? |
Protosmia (Protosmia) exenterata | ? | resin | resin | up to 5 | ? | ? |
Protosmia (Protosmia) glutinosa | ? | resin | ? | 1 | ? | ? |
Protosmia (Protosmia) paradoxa | ? | resin | resin | ? | ? | ? |
Protosmia (Protosmia) sideritis | ? | ? | ? | ? | ? | ? |
Protosmia (Protosmia) stelidoides | ? | resin | resin | 2-4 | ? | ? |
Protosmia (Protosmia) tauricola | ? | ? | ? | ? | ? | ? |
Wainia (Caposmia) atrorufa | ? | large pieces of petals | succession of several partitions of large petal pieces followed by a wall built from a mixture of cemented sand and plant matter | several | linear | ? |
Wainia (Caposmia) braunsi | ? | ? | ? | ? | ? | ? |
Wainia (Caposmia) elizabethae | ? | sand grains cemented together with a resinuous substance (saliva?) | layer of loose sand followed by a wall of sand grains cemented together with a resinuous substance (saliva?) | 1-3 | linear | ? |
Wainia (Caposmia) gessorum | ? | large pieces of petals | succession of several partitions of large petal pieces followed by a wall built from a mixture of cemented sand and plant matter | several | linear | ? |
Wainia (Caposmia) sexsignata | no | large pieces of petals | succession of several partitions of large petal pieces followed by a wall of leaf pulp | 3 | linear | ? |
V. Mauss (Staatliches Museum für Naturkunde Stuttgart) and R. Prosi (Crailsheim) participated in an excursion to southern Morocco, where the nests of Wainia sexsignata were discovered. A. W. Ebmer (Puchenau), S. Gess (Albany Museum and Rhodes University Grahamstown), G. Le Goff (Barentin) and J. Ortiz-Sanchez (Universidad de Almería) provided unpublished observations on the biology of snail shell nesting osmiine bees. E. Neubert (Naturhistorisches Museum Bern) identified the snail shells. M.A. Bologna (University Roma Tre) identified the blister beetle pupa and provided literature on Sitarobrachys. F. Gusenleitner and M. Schwarz (Biologiezentrum Linz) allowed removal of pollen from collected specimens of Wainia eremoplana. G. Le Goff, A. Krebs (Winterthur), V. Mauss, G. Pisanty (Canadian National Collection of Insects, Ottawa), N. Vereecken (Université Libre de Bruxelles) and P. Westrich (Kusterdingen) provided photos. Comments by Jack Neff and Michael Ohl improved the manuscript.