Reprinted with permission of the American Entomological Society from:
LaBerge, W. E. 1977. A revision of the bees of the genus Andrena of the Western Hemisphere. Part VIII. Subgenera Thysandrena, Dasyandrena, Psammandrena, Rhacandrena, Euandrena, Oxyandrena. Transactions of the American Entomological Society 103: 1-144.
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This species is known only from a few females from California. It is similar to Andrena taeniata but differs in the finer facial sculpturing as described below, the lack of internal propodeal hairs anteroventrally, the shagreened clypeus and the clear tergal apical areas.
FEMALE. MEASUREMENTS AND RATIOS. — N = 4; length, about 11 mm width, about 3.5 mm; wing length, M = 4.04 ± 0.203 mm; FL/FW, M = 0.94 ± 0.011; FOVL/FOVW, M = 3.57 ± 0.063.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical half rufescent; flagellum below reddish-brown; tegula translucent reddish-brown; wing membrane hyaline, slightly infumate, veins dark brown to reddish-brown; terga 2-4 with apical areas hyaline, from rufescent at disc to clear at apex, at least apical half colorless; sterna 2-5 narrowly hyaline apically; distitarsi and hind basitarsus dark reddish brown; tibial spurs pale.
STRUCTURE. — Antennal scape length equal to first three and one-third to three and one-half flagellar segments; flagellar segment 1 equal in length to following two and one-fourth segments, segment 2 about equal to 3 and shorter than 4, 2 and 3 shorter than broad, 4-9 quadrate. Eyes each three and three-fourths times as long as broad or longer, inner margins converging slightly towards mandibles (almost parallel). Malar space, mandible and galea as in medionitens. Maxillary palpus as in medionitens but segmental ratio about as 1.0:0.9:0.7:0.7:0.7:0.6. Labial palpus as in medionitens but ratio about as 1.0:0.6:0.4:0.4. Labral process rhomboid, bidentate labrum below process without cristae, convex, punctate. Clypeus convex but low, with small punctures separated by half to one puncture width or less, without median impunctate line, surface with reticulotransverse shagreening which is most dense basally but extends over all or most of clypeus. Supraclypeal area dulled by fine shagreening and minute crowded punctures. Genal area in profile equal to one and one-half times width of eye or more; dulled by reticular shagreening and minute punctures separated by one to two puncture widths. Vertex above lateral ocellus slightly shorter than one ocellar diameter (about as 7:9 or 8:9); evenly tessellate without obvious punctures. Face above antennal fossae with fine longitudinal rugulae which do not reach ocelli or between lateral ocellus and fovea, area surrounding ocelli evenly tessellate. Facial fovea narrow, shallow, extending below to just below a line at lower margins antennal fossae, separated from lateral ocellus by about one and one-half ocellar diameters.
Pronotum as in medionitens. Mesoscutum and scutellum as in taeniata but scutellum often moderately shiny. Propodeum as in taeniata but dorsal surface short, enclosure in one specimen with fine transverse rugulae at base and lateral surfaces shiny with only a few (5 to 7) piliferous punctures in dorsoposterior half or less. Mesepisternum as in taeniata. Wing venation and vannal lobe hind wing as in medionitens but vein 1st m-cu meets second submarginal cell near middle of cell and pterostigma about as broad as from inner margin prestigma to wing margin.
Metasomal terga sculptured as in taeniata but punctures of discs and apical areas smaller, discs virtually impunctate. Pygidial plate V-shaped with rounded apex, internal triangle not raised (one specimen with rounded, raised, longitudinal midline). Sterna as in medionitens.
VESTITURE. — Generally ochraceous, dorsum of thorax bright ochraceous, except as follows: facial fovea with upper half reddish-brown; terga 2-4 with discs with short, suberect, dark brown, relatively sparse hairs; terga 5 and 6 with pale brown to dark ochraceous hairs at least medially; basitibial plate and hairs immediately below plate dark brown (but posterior scopal hairs pale). Clypeus with short hairs partially obscuring surface; thoracic dorsum with hairs erect, short; metanotum with hairs concentrated into median tuft; tergum 1 without apical fascia or restricted to extremely short lateral patches, almost bare medially; terga 2-4 with pale apical fasciae, complete on 3 and 4, interrupted medially by almost one-third width of tergum on 2. Pollen-collecting hairs as in taeniata except propodeal corbiculum with internal long simple hairs restricted to five or six hairs in dorsoposterior half or less of corbiculum, lower anterior half bare.
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