Tachytes obscurus Cresson, 1872:217, ♀. 3 ♀♀, Texas (leg. Belfrage). - Fox, 1892Fox, W.J. 1892. Monograph of the North American species of Tachytes. Transactions of the American Entomological Society 19:234-252. (distribution); Ashmead, 1894Ashmead, W.H. 1894. Notes on cotton insects found in Mississippi. Insect Life 7 (3):240-247. (distribution); Dalla Torre, 1897Dalla Torre, C.G. 1897. Catalogus hymenopterorum hucusque descriptorum systematicus et synonymicus. Volumen VIII: Fossores (Sphegidae). Breitkopf & Härtel, Leipzig. 1-749. (distribution); Banks, 1942Banks, N. 1942. Notes on the United States species of Tachytes. Bulletin of the Museum of Comparative Zoology 89:395-436. (distribution); Krombein, 1963Krombein, K.V. 1963. Natural history of Plummers Island, Maryland. XVII. Annotated list of the wasps (Hymenoptera: Bethyloidea, Scolioidea, Vespoidea, Pompiloidea, Sphecoidea). Proceedings of the Biological Society of Washington 76:255-280. (distribution). - As Tachytes chrysopyga obscurus: - 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); Bohart, 1979Bohart, R.M. 1979. Tachytes of South America (Hymenoptera, Sphecidae, Larrinae). Transactions of the American Entomological Society 104:435-505. (distribution); Amarante, 2002Amarante, S.T.P. 2002. A synonymic catalog of the neotropical Crabronidae and Sphecidae (Hymenoptera: Apoidea). Arquivos de Zoologia (São Paulo) 37:1-139. (distribution); Horta Vega et al., 2013Horta Vega, J.V., M. Vanoye-Eligio, M.E. García-Gutiérrez, J.M.Coronado-Blanco & L. Barrientos-Lozano 2013. Crabronidae (Hymenoptera) de la localidad Cañón del Novillo, Victoria, Tamaulipas, México. Acta Zool. Mex. (n.s.) 29 (2):376-387. (distribution).
Tachytes texanus Cresson, 1872:217, ♂. 5 ♂♂, Texas (leg. Belfrage, Boll). - Fox, 1892Fox, W.J. 1892. Monograph of the North American species of Tachytes. Transactions of the American Entomological Society 19:234-252.:251 ( listed as synonym of Tachytes obscurus Cresson, 1872); Dalla Torre, 1897Dalla Torre, C.G. 1897. Catalogus hymenopterorum hucusque descriptorum systematicus et synonymicus. Volumen VIII: Fossores (Sphegidae). Breitkopf & Härtel, Leipzig. 1-749. (distribution); 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.:1626 ( listed as synonym of Tachytes chrysopyga obscurus Cresson, 1872); Amarante, 2002Amarante, S.T.P. 2002. A synonymic catalog of the neotropical Crabronidae and Sphecidae (Hymenoptera: Apoidea). Arquivos de Zoologia (São Paulo) 37:1-139.:37 ( listed as synonym of Tachytes chrysopyga obscurus Cresson, 1872).
Tachytes hirsutifrons Banks, 1942:430, ♂. Holotype ♂, Tempe, Arizona, 2 August (M.C.Z., no. 25635, leg. Bequaert). - 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.:1626 ( listed as synonym of Tachytes chrysopyga obscurus Cresson, 1872); Amarante, 2002Amarante, S.T.P. 2002. A synonymic catalog of the neotropical Crabronidae and Sphecidae (Hymenoptera: Apoidea). Arquivos de Zoologia (São Paulo) 37:1-139.:37 ( listed as synonym of Tachytes chrysopyga obscurus Cresson, 1872).