Megachile gemula Cresson, 1878:118, Mitchell, 1935Mitchell, T.B. 1935. A revision of the genus Megachile in the Nearctic Region. Part III. Taxonomy of subgenera Anthemois and Delomegachile (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 61 (3):155-205.:183, Type ♂ (A.N.S.P., no. 2425). - Mitchell, 1928Mitchell, T.B. 1928. Sex anomalies in the genus Megachile, with descriptions of new species (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 54 (4):321-383. (distribution); Mitchell, 1935Mitchell, T.B. 1935. A revision of the genus Megachile in the Nearctic Region. Part III. Taxonomy of subgenera Anthemois and Delomegachile (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 61 (3):155-205. (distribution); Mayer et al., 2000Mayer, D.F., E.R. Miliczky, B.F. Finnigan & C.A. Johansen 2000. The bee fauna (Hymenoptera: Apoidea) of southeastern Washington. Journal of the Entomological Society of British Columbia 97:25-32. (distribution); Wilson et al., 2010Wilson, J.S., L.E. Wilson, L.D. Loftis & T. Griswold 2010. The montane bee fauna of north central Washington, USA, with floral associations. Western North American Naturalist 70 (2):198-207. (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).
Megachile avara Cresson, 1878:123 - Mitchell, 1935Mitchell, T.B. 1935. A revision of the genus Megachile in the Nearctic Region. Part III. Taxonomy of subgenera Anthemois and Delomegachile (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 61 (3):155-205.:181 ( listed as synonym of Megachile gemula Cresson, 1878).
Megachile vancouverensis Provancher, 1888:425 - Mitchell, 1935Mitchell, T.B. 1935. A revision of the genus Megachile in the Nearctic Region. Part III. Taxonomy of subgenera Anthemois and Delomegachile (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 61 (3):155-205.:181 ( listed as synonym of Megachile gemula Cresson, 1878).
Megachile albula Lovell & Cockerell, 1907:18, ♂. 2 ♂♂, Maine, July 30th. - Cockerell, 1908Cockerell, T.D.A. 1908. Descriptions and records of bees. - XVIII. The Annals and Magazine of Natural History ser. 8: v. 1 (3):259-267. (distribution); Mitchell, 1935Mitchell, T.B. 1935. A revision of the genus Megachile in the Nearctic Region. Part III. Taxonomy of subgenera Anthemois and Delomegachile (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 61 (3):155-205.:181 ( listed as synonym of Megachile gemula Cresson, 1878). - As Megachile gemula albula: - Cockerell, 1919Cockerell, T.D.A. 1919. Descriptions and records of bees. - LXXXVII. The Annals and Magazine of Natural History ser. 9: v. 4 (23):355-360. (distribution).