Tachytes mergus Fox, 1892:250, ♀. ♀, Camden County, N. J., July 6, 1890. - 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. (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). - As Tachyoides mergus: - Banks, 1942Banks, N. 1942. Notes on the United States species of Tachytes. Bulletin of the Museum of Comparative Zoology 89:395-436. (distribution), 434 (comb. nov.).
Tachytes minor Rohwer, 1909:127 - Banks, 1942Banks, N. 1942. Notes on the United States species of Tachytes. Bulletin of the Museum of Comparative Zoology 89:395-436. (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.:1627 ( listed as synonym of Tachytes mergus Fox, 1892); 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 mergus Fox, 1892).
Tachytes obscuranus Rohwer, 1909:205 - Banks, 1942Banks, N. 1942. Notes on the United States species of Tachytes. Bulletin of the Museum of Comparative Zoology 89:395-436.:434 ( listed as synonym of Tachyoides mergus (Fox, 1892)); 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.:1627 ( listed as synonym of Tachytes mergus Fox, 1892); 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 mergus Fox, 1892).
Tachyoides ariella Banks, 1942:434, ♀. Holotype ♀, Tempe, Arizona, 1 August (M.C.Z., no. 25642, leg. Bequaert). - As Tachytes ariella: - 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.:1627 ( listed as synonym of Tachytes mergus Fox, 1892); 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 mergus Fox, 1892).