Reprinted with permission of the American Entomological Society from:
LaBerge, W. E. 1985. A revision of the bees of the genus Andrena of the Western Hemisphere. Part XI. Minor subgenera and subgeneric key. Transactions of the American Entomological Society 111: 440-567.
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This interesting primitive species can be recognized in the female sex by the moderately bowed out, almost impunctate clypeus, the large, blunt or apically rounded pygidial plate, the short malar space, and the well-formed tergal pale' fasciae. The male is distinctive because of the large, well-formed pygidial plate, the yellow clypeus, and the genal area with a process directed posteriorly from near the midpoint of the hind margin.
FEMALE. MEASUREMENTS AND RATIOS: N = 10; length, 10-12 mm; width, 3.0-3.5 mm; wing length, M= 4.13± 0.358 mm; FL/FW, M= 0.97 ±0.006; FOVL/FOVW, M= 2.81 ±0.060.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical half or more rufescent; flagellum dark brown to black below; tegula translucent, yellowish brown to yellow; wing membranes moderately infumate, yellowish brown, veins red; tibial spurs testaceous; tarsi dark rufescent; terga with narrow apical margins hyaline, clear to yellow; sterna with apical areas hyaline, yellow to colorless.
STRUCTURE. — Scape length equals slightly more than first three flagellar segments; flagellar segment 1 short, one and one-half times as long as segment 2, which is about as long as 3 and as long as broad or slightly longer; median segments slightly longer than broad. Eyes each about three and one-half times as long as broad, inner margins converging toward vertex. Malar space short, minimum length equals about one-fifth basal mandibular width or less. Mandible, when closed, extends beyond midlabrum by one-fifth its length, with subapical tooth. Galea broad at base, outer margin in apical half slightly concave, shorter than midclypeal length; surface dull, finely shagreened, impunctate. Maxillary palpus exceeds galea by slightly more than last two segments; segmental ratio about 1.0:1.0:0.7:0.7:0.6:0.5. Labial palpus with first segment long, curved; segmental ratio about 1.0:0.6:0.5:0.5. Labral process small, more than twice as broad at base as long, trapezoidal with shallow but distinct median emargination, with distinct transverse depression at base; labrum apical to process convex to flat, without cristae or with weak median crista. Subgenal coronet absent. Clypeus moderately bowed outward, with obscure shallow punctures and reticular shagreening dulling surface (impunctate in general appearance). Supraclypeal area finely tessellate, impunctate. Face above antennal fossae with fine longitudinal rugulae diverging toward ocelli, interrugal punctures obscure. Facial fovea broad throughout, shallow, extending down to below line at lower margins antennal fossae, separated from lateral ocellus by half to three-fourths an ocellar diameter. Vertex above lateral ocellus equals about one ocellar diameter, tessellate with small punctures in area above ocelli. Genal area in profile much broader than eye (about as 3:2); surface reticularly shagreened with scattered punctures.
Pronotum reticularly shagreened. Mesoscutum opaque, tessellate with sparse minute punctures. Scutellum like mesoscutum, but punctures almost absent. Propodeum with dorsal enclosure evenly tessellate; dorsolateral and posterior surfaces tessellate with scattered round punctures; lateral surface coarsely tessellate, moderately shiny. Mesepisternum opaque, tessellate with scattered small punctures. Hind tibia narrow.
Metasomal terga 1-5 dull, tessellate, sparse scattered punctures minute, not much bigger than tesserae. Pygidial plate large, apex rounded, truncate, or slightly emarginate; internal raised triangular area present, well separated from margin of plate by a smooth, slightly depressed area. Sterna 2-5 with apical areas impunctate; basal areas with small punctures separated by one to two puncture widths near apical area, sparse at base; surfaces moderately dulled by fine reticular shagreening.
VESTITURE. — Generally ochraceous; thoracic dorsum brighter (almost fox-red) yellow-ochre; facial fovea with pale hairs; terga 1-4 with apical pale fasciae. Propodeal corbiculum without plumose hairs anteriorly, interior with long simple hairs; trochanteral flocculus complete; tibial scopal hairs long, simple, abundant.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 7-11 mm; width, 1.5-3.0 mm; wing length, M=3.44±0.262 mm; FL/FW, M= 1.02±0.007; FS1/FS2, M=0.60± 0.053.
INTEGUMENTAL COLOR. — Black with same exceptions as in female except as follows: mandible with apical fourth or less rufescent; clypeus yellow; flagellum dark reddish brown to black below; terga 2-5 with apical areas translucent, yellow; tarsi red.
STRUCTURE. — Antennae moderately long, reaching metanotum in repose; scape length equals first two and one-fourth flagellar segments; flagellar segment 1 short, about two-thirds as long as segment 2 or shorter; segments 2-11 longer than broad. Eyes each about three and one-third times as long as broad, inner margins parallel to converging slightly toward vertex. Malar space as in female. Mandibles long, decussate, with small subapical tooth. Galeae as in female. Maxillary palpus as in female, but segmental ratio about 1.0:1.0:1.0:0.9:0.7:0.7. Labial palpus as in female, but ratio about 1.0:0.6:0.5:0.6. Labrum as in female. Clypeus as in female but shinier, punctures minute, sparse, more distinct than in female. Supraclypeal area and face above antennal fossae as in female. Vertex above lateral ocellus equals one ocellar diameter in small specimens to one and one-half diameters in large specimens, sculptured as in female. Genal area in profile broad, flat, with large, blunt, finger-like process posteriorly opposite middle of eye; width of level of process almost twice eye width; sculptured as in female.
Thoracic form and sculpturing as in female. Terga sculptured as in female but shinier, becoming especially shiny in terminal three or four terga, surface shagreened rather than tessellate. Tergum 7 with distinct, large, shiny, almost U-shaped, pygidial plate. Sterna 2-5 as in female, but basal area punctures sparse, separated by three to four puncture widths, evenly distributed. Sternum 6 deeply emarginate apically. Penis valve expanded dorsally, with attenuated apex; dorsal lobe gonocoxite large, blunt. Sternum 7 deeply emarginate. Sternum 8 entire apically (Figs. 42-46).
VESTITURE. — Generally ochraceous to pale ochraceous; terga 2-4 or 5 with thin apical pale fasciae, often interrupted medially on tergum 2; sterna 2-5 with short subapical fimbriae.
Reprinted with permission from: Mitchell, T.B. 1960. Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141.
FEMALE — Length 11 mm.; clypeus broadly convex, projecting about one-half below suborbital line, somewhat shining along apical margin, otherwise rather dull, finely tessellate, very finely and quite sparsely punctate, punctures becoming rather close at extreme sides; facial foveae broad, occupying above nearly entire space between eyes and ocelli, covered with pale ochraceous tomentum; space between margin of vertex and lateral ocelli subequal to their diameter; cheeks slightly broader than eyes, rounded posteriorly, rather dull, punctures exceedingly minute and obscure; malar space equal to about one-fourth width of mandible; basal segment of flagellum very slightly shorter than 2nd and 3rd combined; process of labrum rather small, subtriangular, apex rather narrowly truncate and slightly emarginate; mandibles quite elongate, inner, subapical tooth located about one-third its length from tip, overlapping about one-third; pubescence of head pale ochraceous, that on thorax bright fulvous above, becoming pale ochraceous to whitish laterally and below, pubescence of legs whitish, becoming pale ochraceous on the more apical segments; thoracic integument rather dull, finely tessellate, punctures of dorsum of thorax inevident, surface obscured by dense pubescence, pleura more thinly pubescent, with very fine, well separated punctures evident anteriorly, becoming more obscure posteriorly; dorsal area of propodeum oblique, triangle finely tessellate, propodeal corbicula rather short, ochraceous, with a thin, poorly developed, anterior fringe; trochanteral floccus white, rather well developed; hind tibiae rather slender and elongate, apex slightly broader than basitarsi, scopa rather dense, hairs of moderate length and entirely simple, whitish, becoming brownish-ochraceous along hind margin; front and middle basitarsi quite slender, narrower than their respective tibiae; wings lightly infuscated, 2nd submarginal cell considerably shorter than 3rd, receiving 1st recurrent about one-third from apex; abdominal terga dull, densely tessellate, entirely impunctate, apical impressed area quite shallow and narrow, discal pubescence suberect, thin, entirely pale, terga 2-4 with quite dense, white, apical fasciae, slightly interrupted on tergum 2 medially, tergum 5 with a brownish, apical fimbria.
MALE — Length 8 mm.; head broader than thorax; length and breadth of face subequal; clypeus broad and rather flat, projecting about one-half below suborbital line, yellow except for two small black spots and the dark apical rim, smooth and shining, finely punctate, punctures well separated medially, becoming quite close at extreme sides, with an obscure median impunctate area; space between margin of vertex and lateral ocelli slightly greater than their diameter; cheeks considerably broader than eyes, somewhat flattened or broadly concave, with a pronounced submedian rounded angle, surface rather dull, punctures exceedingly minute and obscure; malar space quite short; basal segment of flagellum very short, not much longer than broad, much shorter than 2nd segment; process of labrum short and rather broad, obscurely truncate apically; mandibles elongate, inner, subapical tooth located about one-fourth of length from the narrowly acute apex, rather strongly bowed, overlapping more than one-third; pubescence of head, thorax and legs entirely pale ochraceous; thoracic integument dull, quite densely tessellate, punctures of scutum very minute and obscure, hardly visible, well separated, those on scutellum inevident; pleura with some very minute and sparse, barely visible punctures above; dorsal area of propodeum rather oblique, triangle finely tessellate; basitarsi testaceous, slender and elongate, much narrower than their respective tibiae; 2nd submarginal cell considerably shorter than 3rd, receiving 1st recurrent near apex; abdominal terga rather dull, the more basal segments microscopically tessellate, punctures exceedingly minute and obscure, hardly visible, apical impressed areas shallow and narrow, mostly yellowish-hyaline, discal pubescence rather long and erect basally, becoming quite short, sparse on the more apical terga, entirely pale, apical fasciae very poorly developed, if at all; apical portion of sternum 8 rather slender and elongate, very slightly narrower medially than at base or apex, the apex rather broadly truncate, clothed beneath with rather short pale pubescence; penis valves slender, distinctly bilobed apically, rather broadly expanded basally, sides rather deeply grooved, gonocoxites slender at base, gradually broadened to form subtriangular apical lobes, gonocoxal lobes much produced, rather narrowly rounded.
DISTRIBUTION — New Jersey to Florida and Texas; March to May.
FLOWER RECORDS — Prunus angustifolia.