taxonID	type	description	language	source
611487AFFFD06623FF55FD67FC08FEE3.taxon	diagnosis	Diagnosis. Xerophasma can be distinguished from all other subgenera of Perdita by the enlarged ocelli (each about 1 / 5 to 1 / 3 width of interocular distance at level of median ocellus) and from all except some members of the subgenus Alloperdita Viereck, (restricted to the eastern United States) by the small triangular, petiolate submarginal cell intercalated between the two submarginal cells normal for Perdita. This third submarginal cell is likely a derived character not homologous to the second submarginal cell found in many Andrenidae (Michener 2007). It is unclear whether it is a synapomorphy for the two subgenera (Danforth 1996, Michener 2007). In Xerophasma, the body color is largely pale caramel-colored, with extensive dark markings on the head and mesosoma in some species, and all species have some degree of light to dark brown tergal banding.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD06623FF55FD67FC08FEE3.taxon	description	Description. Female. Length: 6.5 – 11.5 mm; forewing length: 4.5 – 8.3 mm. Body off-white to caramelcolored except dark brown pygidial plate and tergal bands and sometimes on face and mesosoma. Pubescence white, fine, mostly short and inconspicuous except long on gena, legs, mesepisternum. Sculpture finely reticulate, shallow on anterior third of mesoscutum. Head slightly wider than long, no wider than mesosoma. Mandible slender, tapering to acute apex (except with subapical tooth in P. celadona), base pale caramelcolored, apex brown. Inner eye orbits parallel to slightly convergent below. Antenna long, slender, with length of flagellomeres equal to or greater than their width. Facial fovea shallowly impressed, dull, linear or elliptical, darker than rest of face. Ocelli enlarged, median ocellar diameter 1 / 5 to 1 / 3 width of interocular distance at level of median ocellus. Gena in lateral view about ½ as wide as eye (except as wide in P. rhondae), widest above middle of eye. Tibial spurs long, straight, slender, tarsal claws with medial tooth. Scopal hairs of hindtibia long, straight, rather sparse, hair on outer side of hindbasitarsus shorter but otherwise similar. Forewing extending to or beyond apex of metasoma. Stigma large, width equal to or slightly broader than first submarginal cell. Marginal cell as long as stigma but not quite reaching halfway to apex of wing. Small triangular, petiolate intercalary submarginal cell almost always present between the normal first and second. Wings hyaline, veins and stigma light brown, except subcostal vein dark brown. Branched hairs surrounding pygidial plate, long hairs on gena and mesepisternum. Pygidial plate acutely angled. Male. Length: 5.5 – 10.5 mm. Forewing length: 4.0 – 7.1 mm. Similar to female except body sometimes darker colored, gena slightly wider in lateral view; tarsal claws bifid, pygidial plate absent. Variation. Occasional specimens of P. vespertina and P. celadona are missing the petiolate intercalated submarginal cell on one or both wings. Such specimens of P. vespertina from Riverside, Nevada, May 1983 are as follows: 3 females and 1 male missing on left wing only, 1 female incomplete on right wing only, 2 females with incomplete right and missing left, 1 female incomplete left, 4 males missing cell on both wings. One P. vespertina male from Mesquite, Nevada 1998 is missing the third submarginal cell on both wings.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD06623FF55FD67FC08FEE3.taxon	distribution	Distribution. Previously known only from the Sonoran and Chihuahuan Deserts (Timberlake, 1953, 1954, 1958), Xerophasma is now known to occur in the Colorado Plateau and the Mojave Desert and on the western margin of the Great Plains (Figs. 26 – 28). All Xerophasma are crepuscular visitors to Onagraceae of the genera Camissonia and Oenothera in desert and semi-desert regions of southwestern North America. They are frequently found associated with sand dunes and vegetated sands.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD66625FF55FF5DFD62FE78.taxon	description	(Figs. 1, 6, 11, 16, 21) Female. Length: 6.5 – 8.0 mm. Forewing length: 4.5 – 5.0 mm. Head, mesosoma dark brown except: creamcolored on mandible basally, lateral margin of clypeus, paraocular area below level of antennal socket, flagellum ventrally, pronotum dorsally, pronotal lobe, tegula, sometimes scutellum; dark reddish brown on labrum, mandible apically; greenish metallic reflections on dark areas of head and mesosoma except barely visible on mesoscutum medially; scutellum sometimes caramel-colored. Legs cream-colored except: light brown on coxae, fore and midfemora basoventrally, midtibia dorsally, mid tarsi except midbasitarsus ventrally, hindtibia; dark brown on hind tarsi. Costal vein, prestigma dark. Stigma with brown margins, center clear. Brown apical bands on T 2 - T 4 or T 5. Frons reticulate but shiny. Mesoscutum, scutellum dull, very sparsely, indistinctly punctate. Hair on mesoscutum sparse, except for dense, short hair anterior to scutoscutellar suture. Mandible with preapical tooth. Labrum with apical margin scarcely convex. Clypeal width dorsally 1.5 – 2 X as wide as subantennal area. Frontal line slightly raised halfway to median ocellus then slightly depressed to median ocellus. Facial fovea dull, linear, densely pubescent, extending from middle of antennal socket 2 / 3 or more of distance to median ocellus. Ocellar area not inflated. Median ocellar diameter equal to 1 / 5 width of frons. Length of vertex behind lateral ocellus less than ocellar diameter. Forecoxa, mesepisternum ventrally with long, simple, erect, apically bent hair. Length of marginal cell on wing margin less than or equal to 1.5 apical width. Pygidial plate acutely angled. Male. Length: 5.5 mm. Forewing length: 4 mm. Head, mesosoma black except: cream-colored on clypeus, paraocular area below level of fovea, spot medially on supraclypeal area, subantennal area, flagellum dorsally and basally, sometimes along dorsal margin of eye, pronotum except dark spot anterior to pronotal lobe, mesepisternum ventrally near forecoxal cavity. Slight metallic green reflections on dark integument of head, almost no metallic reflection on mesoscutum or mesepisternum. Foreleg, midleg entirely caramel colored except tibiae with brown posterior longitudinal stripe, faint on foreleg. Hindleg caramel-colored except hindfemur dark distally and dorsally, hindtibia, hindbasitarsus and hindtarsi brown dorsally. Brown bands apically on otherwise cream colored terga. T 2 lateral fovea forming fine dark line. Sculpture, punctation, pubescence as in female except mesoscutum, scutellum polished. Clypeal width dorsally greater than width of subantennal area. Supraclypeal area not protuberant, without tuft of hair. Facial fovea appearing glabrous, indistinct, barely visible as small, slight oval indentation where light and dark markings meet. Frontal line, ocellar diameter, forewing as in female. T 7 with pygidial plate illdefined, without apical tuft of hair protruding from beneath apical margin. S 8 as in Fig. 16. Genitalia as in Figs. 6, 11.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD66625FF55FF5DFD62FE78.taxon	materials_examined	Type material. Holotype female: USA NEVADA, Clark County, St. Thomas Gap, 36 ° 24.35 ' N 114 ° 5.62 ' W, 8 Jun 1998, Camissonia, T. Griswold. Paratypes: NEVADA, Clark County: 1 male, 6 females, same label data as holotype; 1 female, Grand Gulch Road, 22 air mi S Mesquite, 11 – 21 May 1983, F. D. & J. H. Parker; 4 females, Mesquite, 25 May 1973, Oenothera, G. Bohart; 3 females, same except 8 May 1994, Oenothera, P. Torchio, D. Veirs; 4 females, Toquap Wash, W Mesquite, 36 ° 46 ' 34 " N 114 ° 11 ' 10 " W, 24 May 2003, Camissonia, D. Yanega; 3 females, Toquap Wash, 1 mi N Hwy I- 15, 485 m, N 36 ° 46 ' 39 " W 114 ° 11 ' 10 ", 25 May 2003, Camissonia, D. Yanega. Holotype deposited in the U. S. National Pollinating Insects Collection, Logan, Utah; paratypes in Logan and Riverside.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD66625FF55FF5DFD62FE78.taxon	diagnosis	Diagnosis. Perdita celadona differs from other Xerophasma by the darker body and truncate rather than rounded or angled apical margin of the labrum. The female pygidial plate is pointed, rather than rounded or truncate as in other Xerophasma, and the mandible has a preapical tooth whereas other species lack a preapical tooth. Range. Apparently endemic to the eastern Mojave Desert in Clark County, Nevada (Fig. 26) where it was active at dusk. Known only from the Virgin River drainage ranging from Mesquite south to St. Thomas Gap. Specimens labeled as collected on Oenothera are actually on plants now assigned to Camissonia (F. D. Parker, personal communication).	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD66625FF55FF5DFD62FE78.taxon	description	Variation. A single female from Mesquite has the dark clypeus interrupted by a pale longitudinal line. The size of the intercalated second submarginal cell varies among individuals. In three (14 %) of the females it is missing on one wing. The female from Grand Gulch Road and all the females from St. Thomas Gap have the scutellum dark, while those from Mesquite have the scutellum pale in contrast to the dark metanotum. T 5 may be all brown except for two oval light spots.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD66625FF55FF5DFD62FE78.taxon	etymology	Etymology. From the French “ celadon ” meaning a sea green color, in reference to the metallic green reflections on most areas of dark integument.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD76626FF55FDB0FDF8FAB6.taxon	description	(Figs. 3, 8, 13, 18, 22) Female. Length: 7.0 – 8.5 mm. Forewing length: 6.2 – 7 mm. Head, mesosoma dark brown to nearly black except: cream-colored labrum, clypeus, paraocular area below level of fovea, spot on vertex between and slightly dorsal to lateral ocelli (sometimes reduced to point), postgenal area along margin of eye, pronotum except spot laterally, ' U' - shaped markings on mesoscutum with base of ' U' at scuto-scutellar margin, arms of ' U' running longitudinally between parapsidal and admedial lines, scutellum, metanotum, tegula, propodeum laterally, legs. Costal vein, prestigma dark. Stigma slightly darkened, ventral margin distinctly darkened. T 1 - 5 with subapical brown bands on otherwise caramel-colored terga. Frons finely reticulate. Mesoscutum, scutellum shiny, mesoscutum anteriorly and laterally slightly reticulate. Mesoscutum moderately densely, distinctly punctate, evenly covered with sparse long pale hair. Propodeal triangle somewhat shiny, finely reticulate. Mandible simple, without preapical tooth. Labrum with apical margin obtusely angulate. Clypeal width dorsally slightly greater than width of each subantennal area. Frontal line strongly raised halfway to median ocellus then strongly depressed to median ocellus. Facial fovea dull, linear, densely pubescent, extending from middle of antennal socket nearly to level of median ocellus. Ocellar area slightly inflated. Median ocellar diameter 1 / 4 width of interocular distance at level of median ocellus. Length of vertex behind lateral ocellus less than 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: 7.5 – 9.0 mm. Forewing length: 5.3 – 5.9 mm. Head, mesosoma, legs cream colored except: entire head slightly yellowed; dark brown on facial fovea, markings anterior to each of lateral ocelli, medially between lateral ocelli, line extending dorsally from median ocellus, marks sometimes forming ” V ” between hindocelli on vertex, occasionally as rings around ocelli, sometimes along dorsal margin of eye orbit; brown subapical band on T 1 and sometimes T 2 – 4. T 2 lateral fovea forming fine, sometimes dark, line. Sculpture, punctation, pubescence as in female. Clypeus dorsally about 1.5 X width of subantennal area. Supraclypeal area not protuberant, without tuft of hair. Facial fovea pubescent, elliptical, minutely depressed, sometimes slightly tear-shaped with narrow end ventral, extending from level of ventral margin of median ocellus to slightly more than halfway to dorsal margin of antennal socket. Frontal line, ocellar diameter, forewing as in female. T 7 with pygidial plate illdefined, with apical tuft of hair protruding from beneath apical margin. S 8 as in Fig. 18. Genitalia as in Figs. 8, 13.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD76626FF55FDB0FDF8FAB6.taxon	materials_examined	Type material. Holotype female: USA NEVADA, Clark County, Mesquite, 36 ° 48.98 ' N 114 ° 04.22 ' W, 26 May 1998, Camissonia, T. Griswold, BBSL 289459. Paratypes: NEVADA, Clark County: 2 females, 7 males, same data as holotype; 1 female, St. Thomas Gap, 36 ° 24.35 ' N 114 ° 5.62 ' W, 8 Jun 1998, Camissonia, T. Griswold; 2 females, 2 males, St. Thomas Gap, 36 ° 24.45 ' N 114 ° 05.58 ' W, 7 Jun 1998, pantrap, F. D. Parker; 2 females, Las Vegas Dunes Rec. Lds., 36 ° 17.27 ' N 114 ° 58.00 ' W, 22 May 1998, light blue pantrap, M. Andres, K. Receveur, K. Keen, C. Shultz; 1 female, 1 male, same except white pantrap; 1 male, same except dark blue pantrap; 1 female, SE of Overton, 36 ° 31.32 ' N 114 ° 26 ' W, 21 May 1998, yellow pantrap, C. Shultz, K. Receveur, K. Keen, M. Andres; 1 female, same except white pantrap; 2 females, same except light blue pantrap; 1 female, same except dark blue pantrap; 21 females, 13 males, Riverside, 11 – 21 May 1983, F. D. & J. H. Parker; 21 females, 55 males, Mesquite, 25 May 1973, at dusk, Oenothera, G. Bohart; 6 females, 12 males, Glendale, 2 Jun 1973, P. F. Torchio; 12 females, 6 males, Toquap Wash, W Mesquite, 36 ° 46 ' 34 " N 114 ° 11 ' 10 " W, 24 May 2003, 19: 30 h., Camissonia, D. Yanega; 2 males, Toquap Wash, 1 mi N Hwy I- 15, 485 m, N 36 ° 46 ' 39 " W 114 ° 11 ' 10 ", 25 May 2003, Camissonia, D. Yanega; 1 female, 3 males, Kaolin Wash, S Overton, 36 ° 30 ' 42 " N 114 ° 26 ' 39 " W, 25 May 2003, D. Yanega; 1 female, 2.16 mi SW Wechech Basin, 11 S E 755235 N 4038290, 13 May 2005, flourescent yellow pantrap, R. Andrus, S. Higbee; 1 female, 0.4 mi E St. Thomas Gap, 11 S E 760620 N 4032979, 12 May 2005, white pantrap, D. Allen, E. Ahlstrom, R. Andrus, S. Higbee; 2 males, 3.9 mi SSW Whitney Pocket, 11 S E 755045 N 4039308, 26 May 2005, white pantrap, R. Andrus, S. Higbee; 1 male, same except flourescent yellow pantrap; 1 male, same except flourescent blue pantrap. Holotype deposited in the U. S. National Pollinating Insects Collection, Logan, Utah; paratypes in Logan and Riverside.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD76626FF55FDB0FDF8FAB6.taxon	diagnosis	Diagnosis. Timberlake recognized this as a new species and gave it a manuscript name that remained unpublished at his death. Perdita vespertina differs from all other Xerophasma except P. celadona in the largely dark mesoscutum. The ocelli of P. vespertina are larger than in P. celadona. Females differ from P. celadona in the simple mandible, pale clypeus, and rounded rather than acute pygidial plate. Males differ in the absence of dark marks above the antennal sockets and the rounded rather than emarginate apex of S 8. The scopa on the hindtibia is denser than in other Xerophasma. Range. Apparently endemic to Clark County, Nevada in the eastern Mojave Desert (Fig. 27) where it was active at dusk. Known only from scattered low elevation, sandy localities from Las Vegas Dunes to Mesquite and St. Thomas Gap. Some specimens were labeled as collected on Oenothera but these were from plants now assigned to Camissonia (Parker, personal communication).	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD76626FF55FDB0FDF8FAB6.taxon	description	Variation. Some individuals lack the intercalated second submarginal cell on one or both wings. The incidence varies among populations. In the Riverside population (n = 36) 22 % have intercalated submarginal cell absent or incomplete on one wing; 11 % missing on both wings. The cell was absent in only one specimen (1 %) of the Mesquite sample (n = 82) and none of the Glendale sample (n = 17). Two females from Glendale, Nevada 1973 had the mesoscutum light, with the mesepisternum light dorsally but brown ventrally.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD76626FF55FDB0FDF8FAB6.taxon	etymology	Etymology. From the Latin, “ vesper ”, meaning evening and west, in reference to the evening flight period and southwestern origin of the bee.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD46628FF55FAE5FF1DF9AE.taxon	description	(Figs. 5, 10, 15, 20, 23) Female. Length: 7.0 – 7.5 mm. Forewing length: 5 – 5.5 mm. Head, mesosoma pale caramel-colored except: most of face cream-colored; dark-brown longitudinal mark above antennal socket, interocellar area, ventral area of mesepisternum; brown lateral longitudinal mark on mesoscutum, U-shaped mark on propodeum. Costal vein, prestigma dark. Stigma slightly stained, ventral margin distinctly darkened. T 1 – 3 with subapical brown bands widened laterally on otherwise caramel-colored terga, on T 4 reduced to lateral spot. Frons shiny. Mesoscutum impunctate, with sparse long pale hair present only anteriorly and laterally. Mesoscutum, scutellum shiny. Propodeal triangle somewhat shiny, finely reticulate. Mandible simple, without preapical tooth. Labrum with apical margin slightly convex. Clypeal width dorsally slightly greater than width of each subantennal area. Frontal line scarcely raised, grooved. Facial fovea dull, linear, densely pubescent, extending from middle of antennal socket two-thirds distance to median ocellus. Ocellar area not inflated. Median ocellar diameter 1 / 6 width of interocular distance at level of median ocellus. Length of vertex behind lateral ocellus greater than ocellar diameter. Forecoxa, mesepisternum ventrally with long, simple, erect, apically bent hair. Length of marginal cell on wing margin less than or equal to 1.5 apical width. Pygidial plate broadly truncate. Male. Length: 5.5 mm. Forewing length: 4 mm. Head, mesosoma, legs pale caramel-colored except: entire face yellow; dark brown between ocelli, posterior to eye, longitudinal line laterally on mesoscutum, propodeum dorsally and posteriorly; brown subapical band on T 1, less distinct bands on T 2 – 4 broadened into spots laterally. T 2 lateral fovea sometimes forming fine dark line. Sculpture, punctation, pubescence as in female except clypeus densely punctate. Clypeal width dorsally approximately two times greater than width of each subantennal area. Supraclypeal area conically protuberant, with tuft of erect, apically bent hair. Facial fovea pubescent, elliptical, minutely depressed, equidistant from level of ventral margin of median ocellus and dorsal margin of antennal socket. Frontal line, ocellar diameter, forewing as in female. T 7 with pygidial plate well defined, with apical tuft of hair protruding from beneath apical margin. S 8 as in Fig. 20. Genitalia as in Figs. 10, 15.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD46628FF55FAE5FF1DF9AE.taxon	materials_examined	Type material. Holotype female: USA California, Inyo Co., Stovepipe Wells, 1.76 mi ENE; Stovepipe Main Dunes, near S margin, 11 S E 489743 N 4051323, 26 Apr 2003, Camissonia, T. & R. Griswold. Paratypes: 6 males, 2 females, same data as holotype. Holotype is the property of the National Park Service and is indefinitely deposited in the U. S. National Pollinating Insects Collection, Logan, Utah; paratypes in Logan and the Death Valley National Park collection.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD46628FF55FAE5FF1DF9AE.taxon	diagnosis	Diagnosis. Females with head more robust than in other Xerophasma, with the vertex longer. The conical protuberance and tuft of hair on the supraclypeal area in the male is not found in other Xerophasma or elsewhere in the genus. Range. Apparently endemic to Death Valley (Fig. 23). Known only from dunes near Stovepipe Wells where it was active at dusk.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD46628FF55FAE5FF1DF9AE.taxon	description	Variation. The size of the dark markings varies slightly in both sexes.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD46628FF55FAE5FF1DF9AE.taxon	etymology	Etymology. This species was discovered after we thought we had completed this manuscript. It is a great pleasure to name this bee after my wife Rhonda, who has been my companion on many an entomological quest, and who discovered these bees on Camissonia as we were leaving the dunes near Stovepipe Wells at dusk.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFDA662AFF55F9E2FBF8FE78.taxon	description	(Figs. 2, 7, 12, 17, 24)	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFDA662AFF55F9E2FBF8FE78.taxon	description	Female. Length: 7.5 – 9.5 mm. Forewing length: 5.4 – 6.7 mm. Head, mesosoma, legs entirely pale caramelcolored, except: face cream-colored; facial fovea dark golden brown; fine dark line sometimes present on vertex medially between lateral ocelli. Costal vein dark, prestigma light, stigma evenly stained, without dark margins. Terga pale caramel-colored except light brown subapical bands on T 1 – 4. Frons, mesoscutum, scutellum shiny; propodeal triangle dull with finely carinulate triangular area basally. Mesoscutum moderately densely punctate, covered with moderately dense hair. Forecoxa, mesepisternum with long apically straight hair, sparse on forecoxa, dense on mesepisternum. Mandible simple, without preapical tooth. Labrum with apical margin obtusely angled. Clypeal width dorsally equal to or slightly greater than width of each subantennal area. Frontal line strongly raised halfway to median ocellus then strongly depressed to median ocellus. Facial fovea sparsely pubescent, linear, shiny to dull, extending from ventral margin of median ocellus to middle of antennal socket. Ocellar area inflated. Median ocellar diameter 1 / 4 interocular distance at level of median ocellus. Length of vertex behind lateral ocellus less than 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 to broadly rounded. Male. Length: 8.0 – 8.5 mm. Forewing length: 5.2 – 5.7 mm. Head, mesosoma, legs pale caramel-colored except: entire head slightly yellow; golden antenna; light brown integumental line on vertex medially between lateral ocelli; dark brown facial fovea, terga without preapical bands except sometimes quadrate brown mark on T 1. T 2 lateral fovea forming fine undarkened line. Sculpture, punctation, pubescence as in female. Clypeus dorsally as wide as subantennal area. Supraclypeal area not protuberant, without tuft of hair. Facial fovea tear-shaped, extending half distance from ventral margin of median ocellus to dorsal margin of antennal socket, indistinct ridge defining fovea. Frontal line, ocellar diameter, forewing as in female. T 7 with pygidial plate ill-defined, without apical tuft of hair protruding from beneath apical margin. S 8 as in Fig. 17. Genitalia as in Figs. 7, 12.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFDA662AFF55F9E2FBF8FE78.taxon	diagnosis	Diagnosis. Perdita pallida can be distinguished from all other P. (Xerophasma) except P. bequaertiana by the entirely pale integument. It differs from P. bequaertiana by the smaller ocelli. Females further differ in the presence of very short hair on the facial fovea and the greater postocellar distance on the vertex; males in the cream to pale yellow frons and the shape of S 8. New material. MEXICO SONORA: El Golfo, 6 mi N, 10 Apr 1975, M. Wasbauer. USA NEVADA Clark County: 2 females, 2 males, 0.4 mi E St. Thomas Gap, 11 S E 760620 N 4032979, 12 May 2005, fluorescent blue pantrap, D. Allen, E. Ahlstrom, R. Andrus, S. Higbee; 2 males, 1 female, same except fluorescent yellow pantrap; 2 males, same except white pantrap; 4 males, 3 females, same except 25 May 2005, fluorescent yellow pantrap, E. Ahlstrom, S. Higbee; 1 male, 1 female, same except 25 May 2005, white pantrap, E. Ahlstrom, S. Higbee; 1 female, same except 20 May 2004, fluorescent blue pantrap, S. Higbee, E. Ahlstrom, D. Skandilis, L. Saul; 1 male, same except fluorescent yellow pantrap; 1 male, white pantrap; CALIFORNIA Imperial County: 1 male, 23 females, Algodones Dunes, 3.5 mi SE Glamis, 28 Apr 1978, at light, A. Hardy, F. Andrews; 1 female, Algodones Dunes, 9.5 mi NW Glamis, Site 37, 32 ° 4 ' 27 " N 115 ° 12 ' 45 " W, 19 Apr 1979; 1 female, Algodones Dunes, S Ruthven, 32 ° 55 ' 30 " N 114 ° 59 ' 34 " W, 6 Apr 2000, at light, D. Yanega; Riverside County: 1 female, Blythe, 22 May 1969, at light, J. Johnson, R. Gill; San Bernardino County: 2 males, 1 female, Kelso Dunes, Mojave National Park, 770 m, 34 ° 35 ' 20 " N 115 ° 43 ' 02 W, 19 May 2001, Oenothera, D. Yanega; 1 male, 1 female, Palen Dunes, 27 Apr 1978, at light, F. G. Andrews, A. R. Hardy; 2 males, Parker Dam, dunes SW, 150 m, 34 ° 155 ’ N 114 ° 08 ’ W, 8 Apr 2005, L. Packer. New records are from the following institutions: Riverside, Sacramento, Davis, and Toronto. Range. Northwestern Sonoran Desert and eastern Mojave Desert in California and adjacent Nevada (Fig. 28).	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFDA662AFF55F9E2FBF8FE78.taxon	description	Variation. Two females in poor condition from north of the known range of P. pallida (California, San Bernardino Co., near Saratoga Springs; Davis collection) may represent this species. They differ by the presence of dark markings on the head. These include a stripe above the antennal socket connected with markings in the interocellar region, and markings on the vertex behind the eye.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD8662BFF55FDB0FCC0FD33.taxon	description	(Figs. 4, 9, 14, 19, 25)	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD8662BFF55FDB0FCC0FD33.taxon	description	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 1 ½ 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 T 1, sometimes with lateral spots on T 2 – 4. T 2 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. T 7 with pygidial plate ill-defined, without apical tuft of hair protruding from beneath apical margin. S 8 as in Fig. 19. Genitalia as in Figs. 9, 14.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD8662BFF55FDB0FCC0FD33.taxon	diagnosis	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.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
611487AFFFD8662BFF55FDB0FCC0FD33.taxon	description	Variation. One specimen from Albuquerque, New Mexico is darker than the rest, with the trochanter and femur of forelegs darkened rather than golden brown.	en	Griswold, Terry, Miller, Wensdae (2010): A Revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa 2517 (1): 1-14, DOI: 10.11646/zootaxa.2517.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2517.1.1
