Halictidae
Sweat bees
The Halictidae
Sweat bees are said to be attracted to salty perspiration, hence their family name from the Greek word hals (”salt”). They share one distinguishing characteristic: the basal vein of the wing is curved (“arcuate”). In all other bees it is straight. In appearance and social organization, sweat bees vary greatly. While many species are merely gregarious, others share the defense of communal nests from predators and kleptoparasites. Some appear to decide whether to build solitary or shared nests depending on year-to-year conditions. Like miner bees, female sweat bees have a pair of bristly scopae on their hind legs; but some of them also carry pollen under their abdomen, like leaf-cutter bees.
Most North American sweat bees belong to four widespread genera. Agapostemon and Halictus have banded abdomen. Banding in Lasioglossum is uncommon. Sphecodes, a kleptoparasitic genus, often has a solid red abdomen.
