Lasioglossum (Dialictus) dreisbachi (Mitchell 1960) ( viridatum group)

Dialictus dreisbachi Mitchell, 1960: 391 . (Michigan holotype)

Holotype. ♀ USA: Michigan: Clare Co.: 24 May 1958 (R. & K. Dreisbach) (NMNH).

County records: Allegan, Antrim, Arenac, Charlevoix, Cheboygan, Clare, Clinton, Crawford, Eaton, Gladwin, Ionia, Iosco, Isabella, Kalkaska, Kent, Lake, Lapeer, Lenawee, Midland, Montcalm, Ottawa, Saginaw, Shiawassee, Van Buren, Washtenaw.

Notes. This species appears to have a northern distribution, reaching its southernmost limits in states that border Canada. Its range remains uncertain due to insufficient sampling in boreal regions of Canada and northern states, and because bee specialists have not been able to distinguish this from other species in the taxonomically challenging Lasioglossum viridatum species group of Gibbs (2010b). Nevertheless, L. dreisbachi has unique mesepisternal sculpturing, which abruptly changes from coarsely rugose to smooth (Gibbs 2010b).

Material examined. Allegan Co.: Trevor Nichols Res. Ctr. N42.6 W86.155, 5–16 Jun. 2015, Malaise trap, J. Gibbs & Y. Nozoe (1 ♀ JBWM) ; Lapeer Co.: Lapper SGA, Norway Lansing, N43.145, W83.353, 28 Jun. 2017, T. Wood (1 ♀ TJWC) ; Ottawa Co.: Marne, 2 km S, N43.0175 W85.8411, 4 Jun. 2015, Leucanthemum vulgare, S. Way (1 ♀ MSUC: RI) ; Van Buren Co.: Brown Lk., N42.0992 W86.1862, 12 May 2014, Prunus cerasus (1 ♀ MSUC: RI).