Perdita scutellaris 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 scutellaris

description: Perdita scutellaris Timberlake
Figs. 3 A, 10G, 11E, 12G, 13E–F, 46, 47A, 57B, 59N–O
Perdita (Heteroperdita) scutellaris Timberlake, 1962: 89, ♂♀. Holotype ♀ (CAS type no. 14701), Hopkins Well, Riverside Co., California, USA.
Diagnosis. Both sexes of P. scutellaris have the metasoma amber or brownish with white stripes apically on the discs of the terga (Figs. 10 G, 11E), propodeum with a yellow triangle (sometimes reduced), scutellum yellow (also sometimes reduced), and lateral face marks that travel up to the apex of the eye (Figs. 12 G, 13E). The only other Heteroperdita with a yellow scutellum is P. wasbaueri, which has the metasoma yellow with black spots. Both sexes of P. scutellaris have a layer of copious, minute hairs on the terga, unique among females of Heteroperdita and in males otherwise present only in P. prodigiosa. The female is unique in having the pygidial plate slender and forked apically (Fig. 24 P)—though the tines of the fork are often broken off, as well as the mandibles spatulate with a distinct ventral hair fringes (Fig. 13 F), and the female can be further recognized by the second medial cell weakened/absent. Males can be further recognized by the head quadrate, pygidial plate triangular, and clypeus not extending apically from the face.
Redescription of female. Length: 3.7 mm. Forewing length: 2.3 mm.
Coloration. Head (Fig. 13 F) and mesosoma base color black, metallic tints reduced or absent; clypeus yellowish-white; supraclypeal mark white, sometimes yellowish, large, transverse; paraocular mark white, narrowly following margin of eye up to apex, coloration increasingly yellow apically; subantennal mark generally dark, sometimes yellowish-white; mandible white, tip reddish; labrum white; scape yellow; antenna yellow except brownish dorsally and on anterobasal margin of F2–F4; pronotal collar dark brown with large yellow transverse mark dorso-posteriorly, transverse mark may be narrowly interrupted medially; pronotal lobe yellow; scutum yellow along lateral margins; axilla yellow; scutellum yellow, sometimes slightly darkened; metanotum occasionally yellow along posterior margin; propodeum with medial yellow triangle, often reduced or poorlydefined; legs dark brown except yellowish-white on apical half of fore femur, anterior face of fore and mid tibiae, distal fore and mid tarsi, joint of mid and hind femora and tibiae, and posterior margin of hind tibia, distal hind tarsi ranging from brown to white; wing veins tan or light brown; metasoma amber or brownish except T1–T5 with white bands along margins of discs and lateral margins of terga, bands thicker laterally and medially (Fig. 11 E); T2 fovea black; pygidial plate amber or brownish.
Structure and vestiture. Head slightly broader than long (Fig. 13 F); face with appressed white pubescence encircling antennal base and on vertex; frons with handful of obscure punctures; eyes subparallel, slightly converging ventrally; facial fovea parallel to eye, oval, length 3X width, extending from top of antennal socket 1/3 distance to apex of eye, generally obscured by pubescence; mandible simple, wide and slightly spatulate with fringe of incurved hairs along ventral margin (Fig. 13 F); labrum quadrate, slightly less than 2X broader than long; disc of clypeus broader than high, convex, clypeus not protruding apically from face; lateral extension protruding below apical margin of clypeus, extending 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 margins of scutum mostly covered by combination of recumbent and erect white pubescence; fore coxa with abundant, broadly hooked hairs; apex of mid tibia with many short, thick, curved setae; forewing with second medial cell absent/weakened; metasoma oval, narrow basally, tapering apically, widest at T3 (Fig. 11 E); terga tessellate, slightly shiny with minute, close punctures; terga covered in short, fine, obscure pubescence, particularly laterally and on apical terga, T1 with patches of short, thick pubescence laterally; T2 fovea short, oval, 1/3 length of T2; pygidial plate very narrow, apex forked with pair of small lateral spines (Fig. 24 P); hairs of prepygidial fimbria slightly thickened, dense.
Redescription of male. Length: 3.5 mm. Forewing length: 2.2 mm.
Coloration. Head (Fig. 12 G) and mesosoma base color black with slight metallic blue or green luster; clypeus, large transverse supraclypeal mark, subantennal mark, and lateral areas yellowish-white; facial sutures may be light or dark; paraocular mark extending up to top of eye, becoming more yellow above; mandible white, tip brown; labrum white; scape yellow; antenna yellow except brownish ventrally and F2–F4 brown dorsobasally; pronotal collar brown with large transverse yellow mark dorso-posteriorly, transverse mark may be slightly interrupted medially; pronotal lobe yellow; scutum lined with yellow along lateral margins; axilla yellow; scutellum yellow, sometimes slightly darkened; metapleuron and anterior propodeum dark brown, sometimes obscurely lightened to tan; metanotum yellow along posterior margin; propodeum black with poorly defined narrow yellow triangle dorso-anteriorly, yellow triangle often reduced or absent; ventral surface of mesepisternum dark brown, lightened to tan on posterior margin; legs yellow except generally marked with brown basally on coxae and basally on femora, hind tibia with faint brown mark medioposteriorly; wing veins tan or light brown; metasoma amber or brownish except T1–T6 with white bands along margins of discs and lateral margins of terga, bands thicker laterally and medially (Fig. 10 G); T2 fovea dark brown; pygidial plate white basally, transparent amber apically.
Structure and vestiture. Head subquadrate or quadrate, broader than long (Fig. 12 G); face, except for clypeus and supraclypeal area, sparsely covered by recumbent white pubescence; eyes parallel or slightly diverging below; mandible simple, thick, slightly curved ventrally, extending to far side of labrum in repose; labrum quadrate, 2X broader than long; disc of clypeus broader than high, slightly convex, not protruding from face apically; lateral extension protruding below apical margin of clypeus, extending to base of mandible; head with dense pubescence ventrally; mesosoma strongly tessellate, impunctate, slightly shiny; pronotal collar slightly impressed, humeral angle weak; mesepisternum completely covered by combination of recumbent and erect white pubescence; scutum mostly covered by combination of recumbent and erect white pubescence; hind tibia with sparse, short, slightly thickened hairs; metasoma equal in width or slightly wider than mesosoma, oval, narrow basally, tapering apically, widest at T3 (Fig. 10 G); terga tessellate, slightly shiny with minute, close punctures; terga covered in extremely fine, obscure pubescence particularly on apical terga; T1 with patches of short, thick pubescence laterally; T2 fovea oval, 3X longer than broad, 1/4 length of T2; pygidial plate broadly triangular, apex narrowly constricted into dull point (Fig. 23 N); hairs of prepygidial fimbria slightly thickened, sparse.
Terminalia. S8 (Fig. 57 B) with spiculum narrow, club-shaped apically, apical edge semicircular; apodemes weakly prominent, very slightly flexed downwards; apical portion moderately convex, quadrate, sides roughly parallel, apex truncate; sparse short hairs ventrally, cuticle apparently lacking weakly sclerotized area. Genital capsule as in Figs. 59 N–O. Gonostyli separated dorsally by broad V-shape; dorsal lobe of gonostylus long and broad, extending to level of penis valve; ventral lobe slightly shorter, narrow with multiple long hairs apically; volsella relatively short and compact; cuspis short, strongly curving dorsally with multiple spicules on outer margin of apex; digitus bizarre with basal flange with few hairs apically, then constricting to tubular shape, evenly curving down and under digitus until pointing upwards again with single spicule apically; penis valve parallel, very close together, apex slightly club-shaped and turned out laterally; endophallus extending to level of apex of penis valve.
Floral records. Boraginaceae (1 ♂ 66 ♀): Tiquilia plicata 1 ♂ 63 ♀, T. sp. 3 ♀, Euphorbiaceae (1 ♂): Chamaesyce parryi 1 ♂, Loasaceae (8 ♂ 15 ♀): Petalonyx thurberi 8 ♂ 15 ♀, Polygonaceae (4 ♂ 2 ♀): Eriogonum deserticola 4 ♂ 2 ♀, Zygophyllaceae (2 ♂ 1 ♀): Larrea tridentata 2 ♂ 1 ♀.
Phenology. Active from April to October.
Distribution. Mojave and Sonoran Deserts (Fig. 47 A), USA (and likely Mexico). Shows a strong preference for dune habitats.
Type material examined. Holotype data: ♀, CALIFORNIA: Riverside Co.: Hopkins Well [reported as “ 18 miles west of Blythe ” in the original publication], 16 April 1958, R.C. Dickson, on Coldenia plicata [= Tiquilia plicata] (CAS type no. 14701). Allotype data: ♂, same data as holotype (UCRC). Paratype data: CALIFORNIA: Imperial Co.: 2 mi W Glamis, Algodones Dunes (32.99388 -115.10388): 3 ♀, 25 Jul 1960, R.C. Dickson, T. plicata; 5.7 mi W Glamis (32.97888 -115.16416): 4 ♂ 2 ♀, 25 Jul 1960, R.C. Dickson, Eriogonum deserticola; E Brawley, 5 mi W Coachella Canal (32.70805 -115.02777): 3 ♀, 28 Jun 1960, R.C. Dickson, T. plicata; Riverside Co.: Hopkins Well (33.6104 -114.995): 2 ♀, 16 Apr 1958, P.D. Hurd, T. plicata.
Additional material examined. Total specimens: 25 ♂ 105 ♀. CALIFORNIA: Imperial Co.: Glamis Dunes, 1 mi W Glamis (32.9941 -115.1013): 5 ♂ 2 ♀, 9 Oct 1988, T.L. Griswold; Glamis, 5.7 mi N (33.0162 -114.9924): 1 ♂, 25 Jul 1961, P.H. Timberlake; Glamis, 6.4 km W; Osborne Overlook, N; sand dunes(32.98784 -115.13862): 1 ♀, 6 May 2012, Z.M. Portman, Tiquilia plicata; Yuma, 32 km W; sand dunes (32.73256 -114.89861): 2 ♀, 26 Sep 2013, Z.M. Portman, T. plicata; Inyo Co.: DEVA; Ibex Dunes, W (35.6939 -116.37206): 21 ♀, 25 Apr 2013, M. C. Orr, T. plicata; Death Valley National Park, Ibex Dunes, E margin, nr. Mine (35.69109 -116.36332): 1 ♀, 8 May 2014, Z.M. Portman, T. plicata; Riverside Co.: Chuckwalla Valley (33.60835 -115.1258): 2 ♂ 1 ♀, 7 Apr 2000, T.L. Griswold, Larrea tridentata; Hopkins Well (33.6104 -114.995): 1 ♀, 16 Apr 1958, P.D. Hurd; San Bernardino Co.: Cottonwood Wash (34.8036 -115.6991): 3 ♀, 2 Jun 1980, T.L. Griswold; 2 ♀, 25 May 1983, T.L. Griswold; Ibex Dune (35.7058 -116.3719): 1 ♀, 1 May 1982, R.W. Rust; Ibex Dunes, E side (35.7148 -116.3861): 2 ♂ 5 ♀, 4 May 1999, R. Andrus; Ibex Dunes, S tip (35.6878 -116.3726): 1 ♀, 4 May 1999, R. Andrus; 19 ♀, 27 Apr 2013, Z.M. Portman, T. plicata; Ibex Dunes, W margin (35.6946 -116.3715): 12 ♀, 4 May 1999, R. Andrus, Petalonyx thurberi; 8 ♀, 27 Apr 2013, Z.M. Portman, T. plicata; 8 ♂ 3 ♀, 8 May 2014, Z.M. Portman, P. thurberi; Ibex Dunes (35.7093 -116.3752): 4 ♂ 7 ♀, 4 May 1999, R. Andrus; Johnson Valley (34.37 -116.5925): 3 ♀, 25 May 2009, G.C. Snelling, T. sp.; Kelso Dunes, Devils Playground Wash, Kelso Dunes Road, 4.1 mi E Kelbaker Road, Mojave National Preserve (34.88888 -115.71722): 1 ♂, 11 Sep 1999, D. Yanega, Chamaesyce parryi; 3 ♀, 19 May 2001, D. Yanega; 3 ♀, 25 May 2009, D. Yanega, T. plicata; Kelso, 2 mi S (34.98218 -115.64875): 1 ♂ 4 ♀, 18 May 1982, J.C. Hall; Rice, 7.4 mi W (34.1033 -114.9731): 1 ♂ 2 ♀, 14 May 2013, G.E. Ballmer.
Remarks. Specimens from the southern localities tend to have the frons slightly shinier and the face with more extensive yellow coloration. For example, the northern specimens (Ibex Dunes) tend to have the subantennal areas dark, while the southern specimens (Algodones Dunes) have the subantennal areas yellow. These differences appear to be minor variation that do not indicate separate 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 70-73, DOI: 10.11646/zootaxa.4214.1.1, http://zenodo.org/record/253086