Metallic Sweatbee (Agopopstemin sp.)

17 June

Members of the family of bees known as Halictidae. Like other sweat bees, they are attracted to human sweat, and they use the salt from the sweat for nutrition. They are generally green or blue, especially the head and thorax. Sometimes the abdomen in females is green or blue although it may be striped, and most males have the yellow-striped abdomen on a black or metallic background.

Nest in the ground, sometimes in dense aggregations. Some species are communal such as A. virescens. In this and other communal species, multiple females share the same nest entrance, but beneath the common entrance burrow, construct their own portion of the nest. Thus each female digs her own brood cells and collects pollen and nectar to fashion the pollen ball upon which she will lay an egg.

Unlike other social bees, in communal bees there is no reproductive division of labor. The advantage of this form of sociality seems to be that cleptoparasitic Nomada bees have greater difficulty gaining access to the nest and brood cells when there are multiple females inside.

In cool temperate regions, there is one generation per year, with females being active in the early summer and males and pre-diapausing females active in the late summer. Only mated females survive the winter. This is probably because unmated females cannot enter diapause. Males can often be seen in large numbers flying around shrubs with large flowers