Genus Wainia
Nest of Wainia (Caposmia) atrorufa from South Africa in a shell of Trigonephrus; the space between the outermost cell partition and the nest plug (not visible) consists of a succession of thick partitions, each built from large petal pieces over which a layer of cemented sand is deposited. Foto S. Gess.
Biogeography and diversity
The genus Wainia is distributed in the Afrotropical, the Palaearctic and marginally also in the Oriental region (Michener, 2007; Ungricht et al., 2008).
Currently, there are 12 described Wainia species worldwide, 2 of which occur in the Palaearctic. Probably 1 Palaearctic species is still undescribed (Gess and Gess, 2008; A. Müller, unpublished).
Phylogeny and classification
The genus Wainia is a member of the Osmia group and sister to the clade Atoposmia+Ashmeadiella+Osmia+Hoplosmia (Praz et al., 2008b). Wainia is subdivided into three subgenera (Michener, 2000, 2007), two of which occur in the Palaearctic:
Caposmia with 2 described Palaearctic species
Wainiella with 1 probably undescribed Palaearctic species
Nesting biology
Information on the nesting biology is available for 3 Afrotropical Wainia species belonging to the subgenus Caposmia (Kuhlmann et al., 2011). All species were observed to nest in empty snail shells and to build one to several brood cells per shell. In two species, the cell partitions are constructed from several layers of large pieces of petals (e.g. Grielum); the space between the outermost cell partition and the nest plug consists of a succession of thick partitions, each built from large petal pieces glued together and over which a layer of cemented sand is deposited. In the same two species, the nest plug is 5-7.5mm thick and consists of several layers of large petal pieces glued together, followed by a very thick layer of heavily cemented sand. In Wainia elizabethae, cell partitions and nest plug consist of sand grains cemented together with a resinous or, more probably, salivary substance; the space between the outermost cell partition and the nest plug is filled with loose sand. (Gess and Gess, 1990, 1998, 1999, 2008; Kuhlmann et al., 2011; S. Gess, personal communication).
Flower preferences
Wainia eremoplana is mesolectic exploiting both Asteraceae and Brassicaceae for pollen.