Sphex philadelphica Lepeletier, 1845:340, ♀. ♀, Philadelphie (Musée de M. Serville). - Cameron, 1888-1900Cameron, P. 1888-1900. Biologia Centrali-Americana - Insecta. Hymenoptera. (Fossores) Vol. II. R. H. Porter and Dulau & Co., London. 413pp, 14 pl.:35 ( listed as synonym of Sphex apicalis Harris, 1835); Fernald, 1942Fernald, H.T. 1942. Annotated list of Florida Sphecinae (Hym., Sphecidae). Entomological News 53 (10):286-291.:288 ( listed as synonym of Chlorion harrisi Fernald, 1906). - As Isodontia philadelphica: - Ashmead, 1894Ashmead, W.H. 1894. Notes on cotton insects found in Mississippi. Insect Life 7 (3):240-247. (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).
Sphex macrocephalus Fox, 1890:137, ♀. Holotype ♀, Fairmount Park, Philadelphia, Pa., 1889. - Fernald, 1942Fernald, H.T. 1942. Annotated list of Florida Sphecinae (Hym., Sphecidae). Entomological News 53 (10):286-291.:287 ( listed as synonym of Chlorion aztecum (Saussure, 1867)); 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.:1582 ( listed as synonym of Isodontia philadelphica (Lepeletier, 1845)). - As Sphex macrocephala: - 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.:73 ( listed as synonym of Isodontia petiolata (Drury, 1773)).
Sphex aztecus digueti Berland, 1927:283 - 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.:1582 ( listed as synonym of Isodontia philadelphica (Lepeletier, 1845)); 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.:73 ( listed as synonym of Isodontia petiolata (Drury, 1773)).