Epeolus utahensis Cockerell, 1921:15, ♂. 3 ♂♂, Utah: Huntsville, near Ogden, July 26, 1920. Synonymized with Triepeolus heterurus Cockerell & Sandhouse, 1924 by Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:70. - As Triepeolus utahensis: - Esperanza de Pedro, 2021Esperanza de Pedro, D. 2021. . :. (distribution).
Epeolus heterurus Cockerell & Sandhouse, 1924:316, ♂♀. Holotype ♀, Redding, California, July 6, 1918 (Mus. Calif. Acad. Sci., No. 1611, leg. E.P. Van Duzee). - Cockerell & Sandhouse, 1924Cockerell, T.D.A. & G. Sandhouse 1924. Parasitic bees (Epeolinae and Melectinae) in the collection of the California Academy of Sciences. Proceedings of the California Academy of Sciences 13 (19):305-324. (distribution). - As Triepeolus heterurus: - Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170. (distribution).
Epeolus piscatoris Cockerell, 1939:432, Brumley, 1965Brumley, R.L. 1965. A Revision of the Bee Genus Epeolus Latreille of Western America North of Mexico. M.S. thesis. Utah State University, Logan, Utah. iii + 92 pp.:73, Holotype (CAS). - Rightmyer, 2008Rightmyer, M.G. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).-Part I. Zootaxa 1710:1-170.:70 ( listed as synonym of Triepeolus heterurus Cockerell & Sandhouse, 1924).