Eucerceris ferruginosa Scullen, 1939:45, Ferguson, 1981Ferguson, G.R. 1981. Synonymy and distribution records in the genus Eucerceris (Hymenoptera: Philanthidae). Journal of the New York Entomological Society 89 (3):172-183.:172, Holotype ♀ (Calif. Acad. Sci., San Francisco). - 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).
Eucerceris baja Scullen, 1949:170, Ferguson, 1981Ferguson, G.R. 1981. Synonymy and distribution records in the genus Eucerceris (Hymenoptera: Philanthidae). Journal of the New York Entomological Society 89 (3):172-183.:172, Holotype ♂ (Calif. Acad. Sci., San Francisco). Synonymized with Eucerceris ferruginosa Scullen, 1939 by Ferguson, 1981Ferguson, G.R. 1981. Synonymy and distribution records in the genus Eucerceris (Hymenoptera: Philanthidae). Journal of the New York Entomological Society 89 (3):172-183.:172. - 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.:62 ( listed as synonym of Eucerceris ferruginosa Scullen, 1939).