Halictus nymphalis mesillensis Cockerell, 1898:47 (key), ♀.Mesilla Valley (leg. Cockerell), Lectotype ♀ (EMEC), designated by Gardner & Gibbs, 2020Gardner, J. & J. Gibbs 2020. The 'red-tailed' Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic. European Journal of Taxonomy 725:1-242.:125. - As Dialictus mesillensis: - 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 Lasioglossum mesillense: - Ruíz-Cancino & Coronado-Blanco, 2002Ruíz-Cancino, E. & J.M. Coronado-Blanco 2002. Artrópodos terrestres de los estados de Tamaulipas y Nuevo León, México. Serie Publicaciones Cientificas No. 4:1-376. (distribution); Gardner & Gibbs, 2020Gardner, J. & J. Gibbs 2020. The 'red-tailed' Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic. European Journal of Taxonomy 725:1-242. (distribution); Esperanza de Pedro, 2021Esperanza de Pedro, D. 2021. . :. (distribution); Nava-Bolaños & Osorio-Olvera, 2022Nava-Bolaños, A. & L. Osorio-Olvera 2022. Estado del arte del conocimiento de biodiversidad de los polinizadores de México. Revista Mexicana de Biodiversidad 93:1-77. (distribution).
Halictus clarissimus Ellis, 1914:222, Gardner & Gibbs, 2020Gardner, J. & J. Gibbs 2020. The 'red-tailed' Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic. European Journal of Taxonomy 725:1-242.:125, Holotype ♀ (USNM). Synonymized with Lasioglossum mesillense (Cockerell, 1898) by Gardner & Gibbs, 2020Gardner, J. & J. Gibbs 2020. The 'red-tailed' Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic. European Journal of Taxonomy 725:1-242.:125.
Halictus perexiguus Sandhouse, 1924:26, ♂. Holotype ♂, Las Cruces, New Mexico, October 12 (U.S.N.M., No. 26423, leg. Cockerell); Gardner & Gibbs, 2020Gardner, J. & J. Gibbs 2020. The 'red-tailed' Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic. European Journal of Taxonomy 725:1-242.:125, Holotype ♂ (USNM). Synonymized with Lasioglossum mesillense (Cockerell, 1898) by Gardner & Gibbs, 2020Gardner, J. & J. Gibbs 2020. The 'red-tailed' Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic. European Journal of Taxonomy 725:1-242.:125.