Xerophasma bequaerti Cockerell, 1923:2, ♀. ♀, Fabens, El Paso Co., Texas, July 9, 1917 (leg. J. Bequaert); Griswold & Miller, 2010Griswold, T. & W. Miller 2010. A revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517:1-14.:11, Holotype ♀ (New York). - Michener, 2000Michener, C.D. 2000. The Bees of the World. The John Hopkins University Press, Baltimore and London. 1-913.:305 ( listed as synonym of Perdita bequaertiana Cockerell, 1951); Griswold & Miller, 2010Griswold, T. & W. Miller 2010. A revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517:1-14.:11 ( listed as synonym of Perdita bequaertiana Cockerell, 1951).
Perdita bequaertiana Cockerell, 1951:1089 - Timberlake, 1953Timberlake, P.H. 1953. Bees of the genus Perdita in the collection of the University of Kansas (Hymenoptera, Apoidea). The University of Kansas Science Bulletin 35, Part 2 (7):961-985. (distribution); Timberlake, 1954Timberlake, P.H. 1954. A revisional study of the bees of the genus Perdita F. Smith, with special reference to the fauna of the Pacific Coast (Hymenoptera, Apoidea). Part I. University of California Publications In Entomology 9 (6):345-432. (distribution); Timberlake, 1958Timberlake, P.H. 1958. A revisional study of the bees of the genus Perdita F. Smith, with special reference to the fauna of the Pacific Coast (Hymenoptera, Apoidea). Part III. University Of California Publications In Entomology 14 (5):303-410. (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); Griswold & Miller, 2010Griswold, T. & W. Miller 2010. A revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517:1-14. (distribution).