Halictus illinoensis Robertson, 1892:271, ♀. 2 ♀♀, Illinois, Aug. 12. - Dalla Torre, 1896Dalla Torre, C.G. 1896. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, X. Apidae (Anthophila). Sumptibus Guilelmi Engelmann, 1-643. (distribution). - As Dialictus illinoensis: - Mitchell, 1960Mitchell, T.B. 1960. Bees of the Eastern United States. Volume I. Technical bulletin (North Carolina Agricultural Experiment Station) 141:1-538. (distribution), 399 (comb. nov.); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209. (distribution). - As Halictus illinoisensis: - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209.:1966 (emendation). - As Halictus illinoisensis: - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209.:1966 (emendation). - As Lasioglossum illinoense: - Owens et al., 2018Owens, B.E., L. Allain, E.C. van Gorder, J.L. Bossart & C.E. Carlton 2018. The bees (Hymenoptera: Apoidea) of Louisiana: An updated, annotated checklist. Proceedings of the Entomological Society of Washington 120 (2):272-307. (distribution).
Halictus politissimus Cockerell, 1917:189 Synonymized with Dialictus illinoensis (Robertson, 1892) by Mitchell, 1960Mitchell, T.B. 1960. Bees of the Eastern United States. Volume I. Technical bulletin (North Carolina Agricultural Experiment Station) 141:1-538.:399. - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209.:1966 ( listed as synonym of Dialictus illinoensis (Robertson, 1892)).