Prosopis sparsa Cresson, 1869:271, ♀. ♀, Pennsylvania (Am. Ent. Soc.). - Dalla Torre, 1896Dalla Torre, C.G. 1896. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, X. Apidae (Anthophila). Sumptibus Guilelmi Engelmann, 1-643. (distribution); Metz, 1911Metz, C.W. 1911. A revision of the genus Prosopis in North America. Transactions of the American Entomological Society 37:85-156.:121 ( listed as synonym of Prosopis modestus (Say, 1837)). - As Hylaeus sparsus: - Mitchell, 1960Mitchell, T.B. 1960. Bees of the Eastern United States. Volume I. Technical bulletin (North Carolina Agricultural Experiment Station) 141:1-538. (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).
Prosopis thaspii Robertson, 1898:43 - Mitchell, 1960Mitchell, T.B. 1960. Bees of the Eastern United States. Volume I. Technical bulletin (North Carolina Agricultural Experiment Station) 141:1-538.:78 ( listed as synonym of Hylaeus sparsus (Cresson, 1869)); 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.:1768 ( listed as synonym of Hylaeus sparsus (Cresson, 1869)).
Prosopis potens Metz, 1911:103, ♂. Holotype ♂, Montreal, Queb., June 10, 1906 (collection of C.F. Baker, Pomona College). - 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.:1768 ( listed as synonym of Hylaeus sparsus (Cresson, 1869)).