Image Credit: Patty O'Hearn Kickham
Banded Green Sweat Bees (Halictidae: Agapostemon)
Male Agapostemon all uniquely have brilliant green heads and thorax and the transversely black & yellow-banded abdomen; female Agapostemon resemble the entirely green Augochlorine Green Sweat Bees but have oval eyes and a transverse ridge completely around their waist. (They are often entirely green, but the abdomen, particularly in more southerly forms, can be variously colored.) Agapostemon are found throughout North America, and are especially abundant in disturbed and agricultural situations. All species of Agapostemon are generalist-feeders.
Agapostemon are apparently all solitary bees, but several species have the tendency for several females to share the same burrow opening, but independently manage separate burrows within. Like other members of the sweat-bees, the immatures develop completely the first year, with fall mating and over-winter hibernation for the females.
The female of most of the US species is entirely brilliant green, whereas the male has a black/brown abdomen with eye-catching yellow stripes. The female can be confused with mason bees (Mason bees carry pollen on the belly, while Agapostemon carries it on the hind legs) and with the Turret-making Sweat-bees (see below).