Bembex Sayi Cresson, 1865:467, ♀. 2 ♀♀, Colorado Territory, 1864 (leg. Mr. James Ridings). - Cresson, 1872Cresson, E.T. 1872. Hymenoptera Texana. Transactions of the American Entomological Society 4:153-292. (distribution); Handlirsch, 1893Handlirsch, A. 1893. Monographie der mit Nysson und Bembex verwandten Grabwespen. VII. (Schluss). Sitzber. Akad. Wiss. Wien Abt. 1 1:657-942, 6 Taf. (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). - As Bembix sayi: - Parker, 1917Parker, J.B. 1917. . 1-155. (distribution); Parker, 1929Parker, J.B. 1929. A generic revision of the fossoriel wasps of the tribes Stizini and Bembicini, with notes and descriptions of new species. Proceedings of the United States National Museum 75:1-203. (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); 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).
Bembix latifrons Parker, 1917:116, ♀. Holotype ♀, Albuquerque, New Mexico, 1894 (University of Kansas, leg. F.H. Snow); Parker, 1929Parker, J.B. 1929. A generic revision of the fossoriel wasps of the tribes Stizini and Bembicini, with notes and descriptions of new species. Proceedings of the United States National Museum 75:1-203.:121, Type ♀ (University of Kansas). - 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.:1711 ( listed as synonym of Bembix sayi Cresson, 1865); 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.:8 ( listed as synonym of Bembix sayi Cresson, 1865).