Reprinted with permission of the American Entomological Society from:
LaBerge, W. E. 1980. A revision of the bees of the genus Andrena of the Western Hemisphere. Part X. Subgenus Andrena. Transactions of the American Entomological Society 106: 395-526.
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Andrena schuhi is a moderate-sized bee from the west coast and inter-montane region; It is closely related to A. vicinoides and A. milwaukeensis which it resembles in both sexes by having the basal inferior mandibular teeth; The female of schuhi can be distinguished from that of either milwaukeensis or vicinoides by the simple labral process which ends in a small swelling, the relatively short clypeus and broad head, and the moderately shiny galeae; The male of schuhi is like that of milwaukeensis in the flat sixth sternum but can be distinguished from the latter by the short clypeus and the often entire labral process; The first flagellar segment of males of schuhi tend to be distinctly longer than the second segment; Viereck (1924) had a mixed series of females when he described A. buckelli of which at least one belongs to the species presently under discussion; Fortunately, the holotype is a male and quite different from the males of schuhi described below.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 11-13 mm; width, 3-4 mm; wing length, M = 4.86 ± 0.212 mm; FL/FW, M = 0.92 ± 0.004; FOVL/FOVW, M = 3.00 ± 0.043.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical two-fifths rufescent; flagellar segments dark brown to dark reddish-brown below; tegula reddish-brown, translucent posteriorly; wing membranes moderately infumate, light brown, veins dark reddish-brown to black; tarsi dark brown to dark rufescent; tibial spurs piceous; sterna with rufescent reflections; terga rarely dark rufescent apically.
STRUCTURE. — Antennal scape length equals about first three flagellar segments; flagellar segment 1 equal in length to following two and one-third segments; segment 2 slightly shorter than segment 3 which is slightly shorter than 4 and about as broad as long; Eyes and mandibles as in vicinoides; Malar space distinct, minimum length equals one-third basal mandibular width or almost; Galea as in frigida but usually quite shiny, reticular shagreening weak especially in basal half; Maxillary palpus as in frigida but segmental ratio about as 0.9:1.0:0.9:0.8:0.6:0.6; Labial palpus as in frigida but ratio about as 1.0:0.5:0.4:0.4; Labral process bluntly triangular or trapezoidal with narrow apex, apex swollen, shiny; labrum apical to process with weak median crista or fold, flat, shiny; Clypeus evenly rounded from side to side, short, in facial view extends beyond line at lower ends of compound eyes by less than half its own length; punctures irregular, sparse apicomedially, usually with broad median impunctate line; shiny, shagreened only in basal fourth or less; Supraclypeal area as in frigida; Face above antennal fossae with longitudinal rugulae and interrugal punctures; Facial fovea as in milwaukeensis; Vertex short, above lateral ocellus equals one ocellar diameter or less, opaque, tessellate and punctate; Genal area in profile broader than eye, shiny near eye, otherwise moderately dulled by reticular shagreening and minute sparse punctures; Thoracic form and sculpturing as in vicinoides except as follows: mesoscutum and scutellum with punctures absent; mesepisternal punctures small, obscure.
Metasomal terga sculptured as in vicinoides; Pygidial plate V-shaped with rounded apex, internal raised triangular area present but weak and often worn away; Sterna as in vicinoides.
VESTITURE. — Generally as in vicinoides but terga 1 and 2 always with pale hairs (fox-red to ochraceous) or at least tergum 1 and basal half or more of tergum 2 with pale hairs; Pollen-collecting hairs as in vicinoides.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 9-11 mm; width, 1.5-2.0 mm; wing length, M = 3.88 ± 0.291 mm; FL/FW, M = 0.92 ± 0.006; FS1/FS2, M = 1.30 ± 0.38.
INTEGUMENTAL COLOR. — As in female but tergal apical areas usually translucent, reddish-brown and sternal apical areas hyaline.
STRUCTURE. — Antennal scape length equals following one and one-half to one and three-fourths flagellar segments; flagellar segment 1 slightly longer to twice as long as segment 2, segment 2 at least slightly shorter than 3 and usually longer than broad; Eyes each three and one-half times as long as broad or slightly less, inner margins parallel or converging slightly towards mandibles; Mandible as in vicinoides; Malar space and galeae as in female; Maxillary palpus as in female but segmental ratio about as 0.9:1.0:1.0:1.0.;0.9:0.9; Labial palpus as in female but ratio about as 1.0:0.8:0.7:0.7; Labral process entire with small, swollen, rounded apex or weakly bidentate with swollen apex, shiny; labrum below process shiny; Clypeus not much flattened, short as in female, with round punctures separated mostly by half to one puncture width, sparser apicomedially, often with narrow median impunctate line; surface entirely shiny or shagreened near base; Supraclypeal as in frigida; Face above antennal fossae as in female, rugulae parallel or almost so, coarse; Vertex as in female but in some large specimens taller than one ocellar diameter; Genal area as in vicinoides; Thoracic form and sculpturing as in vicinoides; Terga sculptured as in vicinoides; Pseudopygidial area of tergum 7 extremely narrow and pointed; Sterna 2-5 as in vicinoides; Sternum 6 with apical margin flat, not reflexed along margin, weakly and broadly emarginate.
Terminalia as in figures 112-116.
VESTITURE. — Generally as in vicinoides but terga 1 and 2 always with pale hairs; thoracic dorsum often with a few dark hairs.
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