Michener (1966) describes the biology of Lasioglossum obscurum from eight nests collected in eastern Kansas, USA. This is a small (5.5-6.5 mm long) greenish black bee and constructs nests by burrowing into the soil. Nests are isolated, rather than occurring in large aggregations as with some other sweat bees. One nests was used three successive summers, so nest re-use occurs. Females overwinter in their natal nest, then emerge the following April to provision cells for their offspring, which will become the first generation of workers; this species is eusocial. Workers emerge at the end of May. Colonies are typically made up of a single queen and her daughters, who serve as workers, although queen replacement can occur if the queen dies. Colonies do not reach large sizes: 6 workers in a nest is the most reported by Michener (1966).
