New and little-known Canadian LasIOGLOssum (DIaLICTus) (Hymenoptera: Halictidae) and an emended key to species

A revised key to the 94 species of Lasioglossum (Dialictus) currently known to occur in Canada is presented, incorporating new species and taxonomic updates since the publication of the first key in 2010. Two new species, Lasioglossum (Dialictus) immigrans and Lasioglossum (Dialictus) onuferkoi, are described from Canada. Lasioglossum (D.) ascheri, L. (D.) stictaspis, and L. (D.) tegulariforme are reported or confirmed from Canada for the first time.

Lasioglossum (D.) gaudiale (Sandhouse, 1924) and L. (D.) helianthi (Cockerell, 1916) are resurrected from synonymy with L. (D.) tegulariforme (Crawford, 1907). The following five new synonymies are established: L. (D.) stictaspis (Sandhouse, 1923) (= L. (D.) albuquerquense (Michener, 1937 )); L. (D.) ascheri Gibbs, 2011 (= L. (D.) curculum Gibbs, 2011); L. (D.) helianthi (Cockerell, 1916) (= L. (D.) imbrex Gibbs, 2010); L. (D.) megastictum (Cockerell, 1937) (= L. (D.) punctiferellum (Cockerell, 1937 )); and L. (D.) obnubilum (Sandhouse, 1924) (= L. (D.) lilliputense Gibbs, 2010).

Previously undescribed males of L. (D.) helianthi, L. (D.) reasbeckae, L. (D.) tegulariforme, and L. (D.) weemsi are diagnosed and figured.