Epeolus penicilliferus Brues, 1903:79 (key), 81, ♂♀. ♂♂♀♀, Austin and Fedor (leg. Brues, Birkmann); Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:102, Types lost?. - As Deringiella penicilliferus: - 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). - As Triepeolus penicilifferus: - Ruíz-Cancino & Coronado-Blanco, 2002Ruíz-Cancino, E. & J.M. Coronado-Blanco 2002. Artrópodos terrestres de los estados de Tamaulipas y Nuevo León, México. Serie Publicaciones Cientificas No. 4:1-376. (distribution). - As Triepeolus penicilliferus: - 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); Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170. (distribution).
Triepeolus perelegans Cockerell, 1921:8, ♂. Holotype ♂, Arizona: Comobabi Mts., about 32° 1' N., 111° 42' W, about 3400 ft. alt, August 9, 1916; Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:102, Holotype ♂ (American Museum of Natural History, No. 25089). Synonymized with Triepeolus penicilliferus (Brues, 1903) by Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:102.
Triepeolus trichopygus Cockerell & Timberlake, 1929:169, ♂♀. Holotype ♂, Riverside, California, July 25, 1927 (leg. Timberlake); Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:102, Holotype ♀ (American Museum of Natural History). Synonymized with Triepeolus penicilliferus (Brues, 1903) by Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:102.