subfamily ROPHITINAE

Dufourea monardae (Viereck, 1924)

A floral specialist (oligolege) on Monarda fistulosa. This female was photographed at the Portland State Game Area, in Ionia County, Michigan. (read more here).

subfamily HALICTINAE

tribe Caenohalictini

Agapostemon sericeus (Forster, 1771)

This beautiful green sweat bee can be found commonly in the East. The nest entrances of this ground dwelling bee are usually well concealed by weeds or grass. Each nest is occupied by a solitary female. It's larger size helps to distinguish it from other green sweat bees in the Augochlorini.

tribe Halictini

Lasioglossum (Dialictus) cressonii (Robertson, 1890)

This is a common sweat bee in eastern North America, but it also occurs as far west as British Columbia. Although most sweat bees nest underground, this species has been observed nesting in wood. 

Lasioglossum (Dialictus) imitatum (Smith, 1853)

This species forms primitively eusocial colonies. Nests are founded by a mated-female in spring. In the summer her daughters take over nest-building and foraging duties while the foundress (now a queen) lays eggs. This is referred to as a reproductive division of labour, which with overlapping generations sharing a nest defines eusociality. The nests of this species are sometimes attacked by a related social parasite: Lasioglossum lionotum.

Lasioglossum (Dialictus) lionotum (Sandhouse, 1924)

This is a social parasite of Lasioglossum imitatum. It can be seen flying low to the ground near nesting sites of its host. Although the female has very large mandibles she does not use them to fight the guards stationed at the nest entrance, but is able to slip into the nest unhindered. However, she may use her massive head and mandibles for confrontations once inside. Lasioglossum imitatum and L. lionotum are very closely related (read more here).

Images are copyright of Jason Gibbs. Please do not use without permission.