Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini) Author Gibbs, Jason text Zootaxa 2011 2011-10-28 3073 1 216 journal article 31531 10.5281/zenodo.1049595 1a985cc7-af57-45e9-a988-c3beda3c15b4 1175-5326 1049595 B5AF6DF4-D3A7-4942-A94F-CC051D8074CF Lasioglossum ( Dialictus ) platyparium (Robertson) Halictus platyparius Robertson, 1895 : 117 . Ƥ. Lectotype . Ƥ USA , Illinois, Macoupin Co. Carlinville, 18.v.1887 (C. Robertson); [INHS: 3995] by W. E. LaBerge (in Webb 1980 ). Examined. Taxonomy. Robertson, 1901 : Paralictus platyparius , p. 229 (generic description); Michener, 1951 : Lasioglossum ( Paralictus ) platyparium , p. 1119 (catalogue); Mitchell, 1960 : Paralictus platyparius Ƥ3, p. 448 (redescription); Krombein, 1967 : Lasioglossum ( Paralictus ) platyparium , p. 467 (catalogue); Paralictus platyparius , p. 1974 (catalogue); Moure & Hurd, 1987 : Paralictus platyparius , p. 143 (catalogue); Gibbs, 2010b : Lasioglossum ( Dialictus ) platyparium Ƥ3, p. 261 (redescription, key). Diagnosis. Female L . platyparium can be recognised by the following diagnostic combination: scopa absent; gena wider than eye; mandible large, converging to point only near apex, distinct preapical tooth absent; labrum with distinct basal tubercle, apical process flat, dorsal keel absent ( Fig. 6 B); and metapostnotum rugoso-carinulate. They are similar to L . cephalotes and L . rozeni . Female L. rozeni have a narrow mandible that is evenly convergent along its entire length and lacks a distinct basal tubercle on the labrum. Female L . cephalotes lack a distinct basal tubercle on the labrum and have a smooth metapostnotum without evident rugae. Male L . platyparium can be recognised by head wide (length/width ratio = 0.95–0.96), dorsolateral angle of pronotum acute, pronotal collar weak, and mesepisternum rugulose. Range. Ontario south to Georgia , Louisiana and west to Minnesota. USA : DC, GA, IL , KS, LA, MD, MN, MO, NC, PA, WV, WI. CANADA : ON. DNA Barcode. Available. Multiple sequences. Comments. Uncommon. Lasioglossum platyparium is presumed to be a social parasite of nest-building Dialictus . It is perhaps the most commonly collected of the parasitic L. ( Dialictus ) but its host species remains unknown.