Perdita arenaria Timberlake
Creators: name: Portman, Zachary M.
name: Neff, John L.
name: Griswold, Terry
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Andrenidae
Perdita
Perdita arenaria

description: Perdita arenaria Timberlake
Figs. 6 A, 7A, 8A, 9A, 23A, 24A, 25, 26A, 56A, 58A–B
Perdita (Heteroperdita) arenaria Timberlake, 1954: 368, ♂♀. Holotype ♂ (CAS type no. 14426), 4 miles east of Edom, Riverside Co., California, USA.
Diagnosis. Both sexes of P. arenaria have the metasoma white or yellow with dark spots (Figs. 6 A, 7A). They can be separated from all similar species except P. yanegai by the following combination of characters: face distinctly broader than long, scutum and scutellum dark, face not entirely yellow below the level of the antenna, metapleuron and anterior propodeum yellow, and propodeum with yellow triangle dorso-anteriorly.
Redescription of female. Length: 3.4 mm. Forewing length: 2.0 mm.
Coloration. Head (Fig. 9 A) and mesosoma base color black with greenish metallic luster except luster generally lacking on frons; clypeus white; supraclypeal mark white, large, transverse; paraocular mark white, transverse to subtriangular, extending to level of summit of clypeus, sometimes with thin line extending along eye to level of top of antennal socket; mandible white, tip reddish; labrum white, sometimes with basomedial dark spot; frons generally black, lacking metallic tints medially; scape white; antenna more or less brown dorsally, whitish ventrally; pronotal collar pale yellow, more or less marked with brown along medial suture; pronotal lobe white; metapleuron and anterior propodeum pale yellow (Fig. 25 A); propodeum with narrow white or yellow triangle dorso-anteriorly (Fig. 5 B); ventral surface of mesepisternum pale yellow along posterior margin; legs pale yellow except more or less darkened to brown on distal hind tarsi; wing veins tan or light brown; metasoma white or yellowish-white with multiple lateral and medial dark brown spots; T1 with pair of sublateral splotches on anterior face (splotches often split into two distinct spots) and pair of sublateral spots on dorsal face; T2–T5 with five spots: one large basomedial triangle, two small baso-lateral spots, and two apico-sublateral spots, basal spots on T2 often merging into continuous basal line, T2 fovea dark brown, lateral spots on T4–T5 generally reduced or absent; pygidial plate transparent white.
Structure and vestiture. Head broader than long (Fig. 9 A); face, except for clypeus, lower supraclypeal area, and frons covered by dense recumbent white pubescence; eyes subparallel, slightly converging ventrally; facial fovea diverging dorsally, narrowly oval, extending from top of antennal socket 2/3 distance to apex of eye, generally more or less obscured by pubescence; mandible simple; labrum quadrate, slightly less than 2X broader than long; disc of clypeus broader than high, convex, apically protruding less than 1 OD from face; lateral extension reaching 1/3 distance to base of mandible; venter of head with abundant inward-facing broadly hooked hairs; mesosoma strongly tessellate, impunctate, slightly shiny; pronotal collar slightly impressed, humeral angle weak; mesepisternum and scutum mostly covered by combination of recumbent and erect white pubescence; fore coxa with abundant, broadly hooked hairs; apex of mid tibia with some short, thick, curved setae; forewing with second medial cell present; metasoma oval, wide basally, tapering apically, widest at T3; terga tessellate and impunctate; T2 fovea linear, slightly thickened, slightly more than 1/2 length of T2; pygidial plate triangular, apex generally rounded (Fig. 24 A); hairs of prepygidial fimbria thin, sparse.
Redescription of male. Length: 2.7 mm. Forewing length: 1.8 mm.
Coloration. Head (Fig. 8 A) and mesosoma base color metallic greenish-bronze; clypeus white, yellow on dorsal and lateral margins; supraclypeal mark yellowish-white, large, transverse; paraocular mark white below, yellow above, more or less completely covering lateral areas below level of facial fovea, continuing up and encircling eye in thin line; subantennal area yellow along margin of antennal socket; mandible white, tip reddish; labrum white, sometimes with basomedial dark spot; scape yellow; antenna yellow, brownish dorsally; pronotal collar yellow; pronotal lobe yellow; metapleuron and anterior propodeum yellow; ventral surface of mesepisternum yellow medially and posteriorly; propodeum with yellow triangle dorso-anteriorly (Fig. 25 B); legs yellow except brown on dorsoapical spot on hind femur, large mark medially on hind tibia, and hind tarsi slightly darkened (Fig. 25 B); wing veins transparent tan or light brown; metasoma yellow or white with multiple brown spots (Fig. 7 A); T1 with pair of sublateral splotches on anterior and pair of sublateral spots on dorsal face; T2–T6 with five spots: one medial irregular spot, two baso-lateral small spots (spot on T2 more transverse), and two prominent apico-sublateral spots, medial spots and spots on apical terga often reduced or absent; T2 fovea dark brown, merging with baso-lateral spots; pygidial plate transparent yellow.
Structure and vestiture. Head oval, width and length equal or slightly broader than long (Fig. 8 A); face, except for clypeus and lower supraclypeal area densely covered by recumbent white pubescence; eyes subparallel, slightly converging ventrally; mandible simple, extending to far side of labrum in repose; labrum quadrate, nearly 2X broader than long; disc of clypeus broader than high, convex, apically protruding less than 1 OD from face; lateral extension reaching 2/3 distance to base of mandible; head with dense long thickened pubescence ventrally; mesosoma strongly tessellate, impunctate, slightly shiny; pronotal collar slightly impressed, humeral angle weak; mesepisternum and scutum densely covered by combination of recumbent and erect white pubescence; hind tibia with sparse, short, thickened hairs; metasoma equal in width or very slightly wider than mesosoma, suboval, wide basally, tapering apically, widest at T3 (Fig. 7 A); terga tessellate and impunctate; T2 fovea narrowly oval, 1/4 length of T2; pygidial plate narrowly triangular, apex rounded, approaching truncate (Fig. 23 A); hairs of prepygidial fimbria slightly thickened, sparse.
Terminalia. S8 (Fig. 56 A) with spiculum bifurcate, lateral apodemes not prominent, slightly flexed downwards; apical portion slightly convex, much longer than broad, sides subparallel, weakly converging to strongly truncate apex; apex strongly folded over dorsally, flattened on top, forming a rough C-shape (with lobes pointing dorsally); sparse short hairs ventrally, circle of cuticle thinned subapically. Genital capsule as in Figs. 58 A–B. Gonostyli separated dorsally by relatively broad V-shape; lobes of gonostylus extending slightly beyond level of penis valve, ventral lobe of gonostylus slightly longer than dorsal lobe with few minute hairs on apex; volsella much shorter than gonostylus; cuspis with couple spicules on outer margin of apex; digitus shorter than cuspis with single spicule on inner margin of apex; penis valve narrow, subparallel, slightly bowed inward medially, narrowed slightly before expanded apex, apex turned slightly outward; endophallus weakly sclerotized basally, extending slightly beyond level of apex of penis valve.
Floral records. Boraginaceae (62 ♂ 9 ♀): Cryptantha sp. 9 ♂, Nama sp. 4 ♂, Tiquilia palmeri 31 ♂ 3 ♀, T. plicata 9 ♂ 6 ♀, T. sp. 9 ♂, Fabaceae (1 ♀): Prosopis sp. 1 ♀.
Phenology. Primarily spring (April to May), except one male collected in September.
Distribution. Mojave and Sonoran Deserts (Fig. 26 A), USA and Mexico.
Type material examined. Holotype data: ♂, CALIFORNIA: Riverside Co.: 4 miles east of Edom, 17 April 1937, P.H. Timberlake, at flowers of Coldenia palmeri [= Tiquilia palmeri (A. Gray) A.T. Richardson] (CAS type no. 14426). Allotype data: ♀, same data as holotype (CAS). Paratype data: CALIFORNIA: Imperial Co.: 2.5 mi N Plaster City (32.82777 -115.85194): 7 ♂ 2 ♀, 1 May 1952, P.H. Timberlake, Tiquilia palmeri; 1 ♂, 1 May 1952, R.C. Dickson, T. palmeri; Truckhaven (33.2987 -115.9772): 2 ♂, 15 Apr 1949, P.H. Timberlake, T. palmeri; 1 ♂, 15 Apr 1949, R.C. Dickson, T. palmeri; Riverside Co.: 4 mi E Edom, Coachella Valley (33.77305 -116.33111): 1 ♂, 17 Apr 1937, P.H. Timberlake, T. palmeri; Box Canyon (33.58333 -115.93333): 1 ♂, 27 Apr 1952, P.H. Timberlake, T. palmeri.
Additional material examined. Total specimens: 57 ♂ 13 ♀. MEXICO: Baja California [Norte]: 25 mi W Mexicali (32.56777 -115.84277): 1 ♂, 18 Apr 1964, E.I. Schlinger. ARIZONA: Yuma Co.: Ligurta (32.6744 - 114.2942): 9 ♂, 13 Apr 1963, G.I. Stage, Cryptantha sp.; Yuma, 10 mi E (32.6691 -114.4682): 1 ♂, 8 Apr 1963, G.I. Stage; Yuma (32.72 -114.62): 9 ♂, 13 Apr 1955, collector unknown, Tiquilia sp.; 12 ♂, 8 Apr 1963, G.I. Stage, T. palmeri. CALIFORNIA: Imperial Co.: Ocotillo, 5.3 km ENE; Roadside of Hwy S 80 (32.75711 -115.94222): 5 ♂ 1 ♀, 2 May 2012, M. C. Orr, T. palmeri; 1 ♂ 1 ♀, 2 May 2012, Z.M. Portman; Ocotillo, 5.4 km ENE; Coyote Wash (32.75707 -115.94122): 1 ♂, 2 May 2012, Z.M. Portman; 1 ♂, 2 May 2012, Z.M. Portman, T. plicata; Ocotillo, 5.4 km ENE; Coyote Wash (32.75793 -115.94101): 3 ♀, 2 May 2012, Z.M. Portman, T. plicata; Ocotillo, 5.9 km ENE (32.75965 -115.93666): 1 ♀, 2 May 2012, Z.M. Portman, Prosopis sp.; Riverside Co.: Blythe (33.61 -114.59): 4 ♂, 16 Apr 1969, P.F. Torchio, Nama sp.; San Bernardino Co.: Ibex Dunes (35.7093 -116.3752): 1 ♀, 4 May 1999, R. Andrus; Kelso Dunes, Devils Playground Wash, Kelso Dunes Road, 4.1 mi E Kelbaker Road, Mojave National Preserve (34.88888 -115.71722): 3 ♂ 2 ♀, 19 May 2001, D. Yanega; 1 ♂, 18 May 2003, D. Yanega, T. plicata; 1 ♀, 25 May 2009, D. Yanega, T. plicata; Kelso Dunes (34.9768 -115.648): 1 ♀, 20 May 1980, T.L. Griswold; Twentynine Palms, 32 road mi E (34.0912 -115.5401): 1 ♂, 6 Sep 2012, T.L. Griswold, T. plicata. NEVADA: Clark Co.: 1.5 mi SSE Jean (35.7611 -115.32): 1 ♂, 10 May 2005, E. Ahlstrom, S.M. Higbee; Davis Dam, W (35.1857 -114.5905): 1 ♂, 13 May 1998, M. Andres, K. Keen, T. palmeri; Sheep Mountain, W (35.753 - 115.31983): 2 ♂ 2 ♀, 22 May 1998, K. Receveur, C. Schultz, T. plicata; Nye Co.: Big Dune, NW tip (36.65679 - 116.59651): 4 ♂, 29 Apr 2013, M. C. Orr, T. plicata.
Remarks. What Timberlake considered P. arenaria is here split into three separate species: P. arenaria, P. nuttalliae, and P. yanegai. While P. nuttalliae is distinct and relatively easy to separate, females of P. arenaria and P. yanegai can be difficult. Despite the relatively distinct characters of the males, the females of these two are extremely similar and often impossible to separate with any level of confidence. These two species mirror the pattern seen in other bee species where the males are able to be separated but the females are largely indistinguishable (e.g. Agapostemon texanus Cresson, 1872 and A. angelicus Cockerell, 1924; P. punctosignata sulphurea Timberlake, 1964 and P. punctosignata flava Timberlake, 1964). As with these two examples, P. arenaria and P. yanegai often co-occur throughout much of their range and are often collected together, though there appear to be areas of their range where only one species is present. Additional specimens and/or molecular investigation may help better resolve the two species.
Perdita arenaria and P. yanegai are extremely similar species that co-occur over most of their ranges. The males can be easily separated but the females cannot be confidently separated in most cases. In the females, there appears to be a tendency for the apex of the pygidial plate to be rounded in P. arenaria (Fig. 24 A) and pointed in P. yanegai (Fig. 24 W). However, there are many specimens that fall between this dichotomy and defy attempts at identification. In addition to the pygidial plate, the frons of P. arenaria appears to be more extensively black and lacking metallic tints while the frons of P. yanegai generally lacks black areas and is metallic throughout. Association with males as a means of identification should be used with caution because the two species commonly co-occur.
Unlike the females, the male of P. arenaria and P. yanegai can be easily separated. The most definitive character is the shape of S8: in P. arenaria, S8 is broader, the sides are more parallel, and has a larger thinned area of the cuticle (Fig. 56 A), whereas P. yanegai has S8 narrower, the sides slightly converging apically, and has a smaller thinned area of the cuticle (Fig. 56 H). In addition, males can be separated from P. yanegai by the following characters: P. arenaria has a well-developed yellow band on the mesopleuron and anterior propodeum (Fig. 25 B). This band is more or less reduced in P. yanegai, typically limited to a yellow spot dorsally on the metapleuron directly below the wing (Fig. 54 B). P. arenaria also has the dark marks on the hind leg well-developed whereas P. yanegai lacks dark marks on the legs (though some specimens may have faint vestigial spots). The light face marks are typically more extensive in P. arenaria, which has a larger subantennal mark and larger paraocular marks which typically fill up the entire lateral area. The pygidial plate of P. arenaria is slightly narrower than P. yanegai, but this character is difficult to assess without direct comparison between species.
description: Published as part of Portman, Zachary M., Neff, John L. & Griswold, Terry, 2016, Taxonomic revision of Perdita subgenus Heteroperdita Timberlake (Hymenoptera: Andrenidae), with descriptions of two ant-like males, pp. 1-97 in Zootaxa 4214 (1) on pages 14-26, DOI: 10.11646/zootaxa.4214.1.1, http://zenodo.org/record/253086