The genus Agapostemon (literally "stamen loving") is a common group of Western Hemisphere sweat bees.

They superficially resemble various members of another tribe, the Augochlorini, which are also typically metallic green.

The advantage of this form of sociality seems to be that kleptoparasitic Nomada cuckoo bees have greater difficulty gaining access to the nest and brood cells when there are multiple females inside.

[citation needed] Some 42 species in the genus range from Canada to Argentina.

In cool temperate regions, there is one generation per year, with females active in the early summer and males and pre-diapausing females active in the late summer.