Coelioxys insita Cresson, 1872:273, ♀. 4 ♀♀, Texas (leg. Belfrage); Baker, 1975Baker, J.R. 1975. Taxonomy of five nearctic subgenera of Coelioxys (Hymenoptera: Megachilidae). The University of Kansas Science Bulletin 50 (12):649-730.:686, Type ♀ (Academy of Natural Sciences of Philadelphia, #2499). - 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); Dalla Torre, 1896Dalla Torre, C.G. 1896. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, X. Apidae (Anthophila). Sumptibus Guilelmi Engelmann, 1-643. (distribution); Brues, 1903Brues, C.T. 1903. Studies of Texan bees. Part 1. Entomological News 14:79-85. (distribution); Baker, 1975Baker, J.R. 1975. Taxonomy of five nearctic subgenera of Coelioxys (Hymenoptera: Megachilidae). The University of Kansas Science Bulletin 50 (12):649-730. (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); 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).
Coelioxys rudis Cockerell, 1934:3, ♂♀. Holotype ♀, Colorado: vicinity of Boulder (The American Museum of Natural History, leg. Mr. Chas); Baker, 1975Baker, J.R. 1975. Taxonomy of five nearctic subgenera of Coelioxys (Hymenoptera: Megachilidae). The University of Kansas Science Bulletin 50 (12):649-730.:686, Type ♀ (American Museum of Natural History). Synonymized with Coelioxys insita Cresson, 1872 by Baker, 1975Baker, J.R. 1975. Taxonomy of five nearctic subgenera of Coelioxys (Hymenoptera: Megachilidae). The University of Kansas Science Bulletin 50 (12):649-730.:686. - 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.:2077 ( listed as synonym of Coelioxys insita Cresson, 1872).