Megachile fortis Cresson, 1872:262, ♂. 2 ♂♂, Texas (leg. Belfrage); Mitchell, 1936Mitchell, T.B. 1936. A revision of the genus Megachile in the Nearctic Region. Part IV. Taxonomy of subgenera Xanthosarus, Phaenosarus, Megachiloides and Derotropis (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 62 (2):117-166.:144, Type ♂ (A.N.S.P., no. 2453). - Cresson, 1879Cresson, E.T. 1879. Catalogue of North American Apidae. Transactions of the American Entomological Society and Proceedings of the Entomological Section of the Academy of Natural Sciences 7:215-232. (distribution); Cockerell, 1899Cockerell, T.D.A. 1899. Notes on american bees (Concluded from p. 129). The Entomologist 32:154-159. (distribution); Cockerell, 1900Cockerell, T.D.A. 1900. The New Mexico bees of the genus Megachile and a new Andrena. The Annals and Magazine of Natural History ser. 7: v. 6:7-20. (distribution); Cockerell, 1901Cockerell, T.D.A. 1901. Flower and insect records from New Mexico. Entomological News 12 (2):38-43. (distribution); Cockerell, 1902Cockerell, T.D.A. 1902. Flowers and insects in New Mexico. American Naturalist 36 (430):809-817. (distribution); Cockerell, 1906Cockerell, T.D.A. 1906. The bees of New Mexico. Transactions of the American Entomological Society 32:289-314. (distribution); Mitchell, 1936Mitchell, T.B. 1936. A revision of the genus Megachile in the Nearctic Region. Part IV. Taxonomy of subgenera Xanthosarus, Phaenosarus, Megachiloides and Derotropis (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 62 (2):117-166. (distribution); Mitchell, 1962Mitchell, T.B. 1962. Bees of the Eastern United States. Volume II. Technical bulletin (North Carolina Agricultural Experiment Station) 152:1-557. (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); Owens et al., 2018Owens, B.E., L. Allain, E.C. van Gorder, J.L. Bossart & C.E. Carlton 2018. The bees (Hymenoptera: Apoidea) of Louisiana: An updated, annotated checklist. Proceedings of the Entomological Society of Washington 120 (2):272-307. (distribution).
Megachile emoryi Cockerell, 1904:7, ♀. ♀, Pecos, New Mexico, on Kinkale Ranch, Aug. 31st, 1903. - Cockerell, 1906Cockerell, T.D.A. 1906. The bees of New Mexico. Transactions of the American Entomological Society 32:289-314. (distribution); 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); Cockerell, 1909Cockerell, T.D.A. 1909. Descriptions and records of bees. - XXI. The Annals and Magazine of Natural History ser. 8: v. 4 (19):25-31. (distribution); Mitchell, 1936Mitchell, T.B. 1936. A revision of the genus Megachile in the Nearctic Region. Part IV. Taxonomy of subgenera Xanthosarus, Phaenosarus, Megachiloides and Derotropis (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 62 (2):117-166.:143 ( listed as synonym of Megachile fortis Cresson, 1872); Mitchell, 1962Mitchell, T.B. 1962. Bees of the Eastern United States. Volume II. Technical bulletin (North Carolina Agricultural Experiment Station) 152:1-557.:156 ( listed as synonym of Megachile fortis Cresson, 1872); 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.:2061 ( listed as synonym of Megachile fortis Cresson, 1872).
Megachile fortis vestali Cockerell, 1913:530, ♂. ♂, Halsey, Nebraska, Aug. 27, 1911 (leg. A.G. Vestal). - Cockerell, 1923Cockerell, T.D.A. 1923. Descriptions and records of bees. - XCVII. The Annals and Magazine of Natural History ser. 9: v. 11 (62):263-269. (distribution); Mitchell, 1936Mitchell, T.B. 1936. A revision of the genus Megachile in the Nearctic Region. Part IV. Taxonomy of subgenera Xanthosarus, Phaenosarus, Megachiloides and Derotropis (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 62 (2):117-166.:143 ( listed as synonym of Megachile fortis Cresson, 1872); Mitchell, 1962Mitchell, T.B. 1962. Bees of the Eastern United States. Volume II. Technical bulletin (North Carolina Agricultural Experiment Station) 152:1-557.:156 ( listed as synonym of Megachile fortis Cresson, 1872); 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.:2061 ( listed as synonym of Megachile fortis Cresson, 1872).