Numbers
484 species in North America listed at
nearctica.com
about 1,500 species worldwide listed at
discoverlife.orgIdentification
They have facial
foveae. This describes the pale bands of hair along the inside margins of the eyes. Actually, the facial foveae are the 'grooves' in the face from which those hairs emanate.
OVERVIEW OF SUBGENERA OF Andrena
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Images needed
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Most of northern hemisphere; absent from South America and Australia - see
Discover Life Global mapSeason
Most species fly in spring, but others fly in the summer, autumn, and a few even in winter
Remarks
Considering the large number of similar-looking species, identification to species level usually requires an expert.
Andrena are more active than Apis at lower temperatures. For this and other reasons Andrena (and Osmia...) can be, on a per bee basis, superior pollinators in cold weather. Some species such as Andrena clarkella are exceptionally cold tolerant. See: Gebhardt, M., and G. Röhr. 1987. Zur bionomie der Sandbienen Andrena clarkella (Kirby), A. cineraria (L.), A. fuscipes (Kirby) und ihrer Kuckucksbienen. Drosera 87: 89-114. Taken from a comment by
John S. Ascher, 12 April, 2009.
The Andrena catalog citation is:
Gusenleitner, F., and M. Schwarz. 2002. Weltweite Checkliste der Bienengattung Andrena mit Bemerkungen und Ergaenzungen zu palaearktischen Arten (Hymenoptera, Apidae, Andrena). Entomofauna Supplement 12: 1-1280. Taken from a
comment by
John S. Ascher, 12 April, 2009.
Internet References
pinned adult images and
brief discussion of about 12 species (Insects of Cedar Creek, U. of Minnesota)
Discover Life list of world species with links to info and images on each species
