Species account taken from "A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae) Authors: TERRY GRISWOLD & WENSDAE MILLER Source: Zootaxa, Vol 2517 (June 24, 2010) pp. 1-14"
Xerophasma bequaerti Cockerell 1923:2. Preoccupied. Holotype female, Fabens, El Paso County, Texas. (New York).
Perdita bequaertiana Cockerell 1951 (In: Michener 1951:1089). N. Name
Female. Length: 9.5–11.5 mm. Forewing length: 7.0–8.3 mm. Head, mesosoma, legs pale caramel colored except frons, facial fovea, vertex reddish brown; scutellum slightly paler than surrounding areas. Costal vein dark. Prestigma light. Stigma evenly stained, without dark margins. Preapical dark bands on otherwise caramel-colored terga. Frons, mesoscutum, scutellum, propodeal triangle dull, reticulate except shiny centrally on mesoscutum, scutellum. Basal area of propodeal triangle with carinulate triangular area.
Mandible simple, without preapical tooth. Labrum with apical margin obtusely angulate. Clypeal width dorsally slightly to 1½ times greater than width of each subantennal area. Frontal line strongly raised halfway to median ocellus, then strongly depressed to median ocellus. Facial fovea rather shiny to dull, appearing glabrous, linear, sometimes narrowed dorsally with slight bend toward eye, extending from dorsal 1/3 of antennal socket to level of ventral margin of median ocellus. Ocellar area strongly inflated. Ocelli greatly enlarged, the trio taking up nearly entire width of interocular distance at level of median ocellus, median ocellus 1/3 interocular distance at level of median ocellus. Length of vertex behind lateral ocellus equal to one-fourth of ocellar diameter. Forecoxa with long, erect, slightly plumose, straight hair; mesepisternum ventrally with short, obliquely directed, straight hair. Length of marginal cell on wing margin twice apical width. Pygidial plate narrowly rounded.
Male. Length: 9.5–11.0 mm. Forewing length: 6.1–7.1 mm. Head, mesosoma, legs pale caramel colored except: paraocular area sometimes pale; facial fovea dark brown; scutellum pale. Indistinct, light brown preapical band on T1, sometimes with lateral spots on T2–4. T2 lateral fovea sometimes forming fine undarkened line. Sculpture, punctation, pubescence as in female.
Clypeal width dorsally greater than width of each subantennal area. Supraclypeal area not protuberant, without tuft of hair. Facial fovea appearing glabrous, elliptical, depressed, narrower and shorter than in female, extending half distance from dorsal margin of antennal socket almost to ventral ocellar margin. Frontal line, ocellar diameter, forewing as in female. T7 with pygidial plate ill-defined, without apical tuft of hair protruding from beneath apical margin. S8 as in Fig. 19. Genitalia as in Figs. 9, 14.
Diagnosis. The greatly enlarged ocelli are unique among Perdita. Perdita bequaertiana is larger than other P. (Xerophasma).
New material. USA ARIZONA, Coconino County: 7 females, Moenkopi, 16 Jul 1994, L. G. Bezark, D. E. Russell; 1 male, Cameron, 1 Aug 1978, R. C. Miller; 1 male, same except 4 July 1977; 1 female, same except 5 Aug 1978; 1 female, same except 15 Aug 1977; Cochise County: 4 females, Willcox, Browontaren 90-33, black light, 18 Aug 1990, J. Schmidt; COLORADO, Bent County: John Martin Reservoir, sand dunes near dam, H. E. Evans, B. Kondratieff, D. & M. Leatherman, M. Weissman, H. Kneuttel; Las Animas County: 1 male, 22 Jul 1963, R. Allen; NEW MEXICO, Bernalillo County: 1 male, 2 females, Albuquerque, 16 Aug 1962, at light, G. E. Bohart, D. C. Heninger; 1 female, same except, 4 Aug 1962, D. C. Heninger; Dona Ana County: 1 female, Las Cruces, 5 Jul 1961, D. C. Heninger; Roosevelt County: 2 males, 2 females, Oasis State Park, 4.0 mi N Portales, 4200 ft, 29 Jul 1975, to light among Oenothera pallid runcinata, 2045-2100 MST, T. J. Zavortink; Socorro County: 11 males, 3 females, La Joya Wildlife Preserve, 1 Jul 1976, W. Rubink; 1 male, 1 female, same except 1–14 July 1976, malaise trap; 2 females, same except 10 Jun 1977; 1 female, same except 13 Jul 1976; 1 female, same except 25 Jul 1976; 1 female, same except 1 Jul 1976, W. Rubink, H. Evans; 1 female, same except 25 Jun 1977, W. Rubink, H. Evans, D. Gwynne; 1 female, same except 17 Aug 1977, W. Rubink, J. Buchholz; Torrence County: Gran Quivira,1 female, 8 Aug 1965, H. B. Leech; 1 female, same except 6500 ft., 19 Aug 1967; 1 male, 4 females, same except 20 Aug 1967, UV light; 1 male, 3 females, same except 18 Aug 1967; TEXAS Ward County: 1 male, 1 female, Monahans Dunes, 12 Jun 1976, H. Evans, W. Rubink, D. Gwynne; UTAH, Grand County: 2 females, 2 males, 9 mi NW Moab, 14 Jul 1994, L. G. Bezark, D. E. Russell. New records are from the following institutions: Davis, Ft. Collins, and Logan.
Range. Southern Great Plains, northern Chihuahuan Desert, and Colorado Plateau (Fig. 28). Known from El Paso and Howard Counties, Texas to Coconino County, Arizona, and Grand County, Utah.
Variation. One specimen from Albuquerque, New Mexico is darker than the rest, with the trochanter and femur of forelegs darkened rather than golden brown.