[1][2] They are highly variable in size, coloration, and sculpture; among the more unusual variants, some are cleptoparasites, some are nocturnal, and some are oligolectic.

[4] The genus Lasioglossum can be divided into two informal series based on the strength of the distal veins of the forewing.

[1] The Hemihalictus series (or weak-veined Lasioglossum) includes species with a wide range of sociality.

[6][4] The Hemihalictus series is composed of species which are solitary, communal, primitively eusocial, cleptoparasitic, or socially parasitic.

Subgeneric classification of Lasioglossum remains controversial, with disagreement among experts on the number and extent of subgenera.