Lasioglossum onuferkoi, Gardner & Gibbs, 2022

Gardner, Joel & Gibbs, Jason, 2022, New and little-known Canadian LasIOGLOssum (DIaLICTus) (Hymenoptera: Halictidae) and an emended key to species, The Canadian Entomologist (e 3) 154 (1), pp. 1-37 : 15-16

The Lasioglossum perdifficile species complex

Species included. Lasioglossum cyanurus (Cockerell, 1936) , L. ebmerellum Gibbs, 2010 , L. marinum (Crawford, 1904) , L. megastictum ( Cockerell, 1937) , L. onuferkoi n. sp., L. perdifficile (Cockerell, 1895) , L. perpunctatum (Ellis, 1913) , L. sheffieldi Gibbs, 2010 , and L. yukonae Gibbs, 2010 (possibly L. sombrerense Engel, 2011 ).

Diagnosis. The Lasioglossum perdifficile complex can be recognised in both sexes by the combination of clypeus strongly projecting below the suborbital tangent, tegula inner posterior margin straight or concave (sometimes weak or obscure, especially when the tegula is folded close to the thorax), metapostnotum relatively long (median length about twice that of metanotum in dorsal view, except in L. cyanurus , L. marinum , and L. megastictum , in which the tegula is punctate) with strong anastomosing rugae reaching the posterior margin (except in L. ebmerellum ), and the propodeum with oblique carina absent or very weak (hardly visible). In addition, females have T1 with appressed tomentum laterally joining the acarinarial fan.

Comments. Lasioglossum punctiferellum ( Cockerell, 1937) (= Halictus (Chloralictus) punctiferellus Cockerell, 1937 ) is herein treated as a subjective synonym of L. megastictum (new synonymy). The holotypes of these two species were collected at the same time and place, and they differ only in minor respects. The holotype of L. punctiferellum has less distinct punctures of the clypeus and mesepisternum, shinier supraclypeal area, and slightly sparser tomentum on T2–T4. Cockerell (1937) also wrote that L. megastictum has T1 and T4 slightly metallic green, but this character was not evident on re-examination of the type material. However, the holotype of L. punctiferellum has all metasomal terga with a very weak metallic bluish sheen, so it is likely that some specimens can occasionally have the terga weakly metallic. No specimens have been seen that exactly match the type of L. punctiferellum , but numerous intermediates exist. The holotype of L. megastictum is more typical of the species in general, and it is therefore given precedence in the absence of publication priority.

Many species in the L. perdifficile complex are known to be sand-habitat specialists ( L. sheffieldi and L. yukonae ( Gibbs 2010) ; L. marinum ( Gibbs 2011) ; L. onuferkoi n. sp. (this paper)).