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.
Please report text errors to: leah at discoverlife dot org.
This moderate-sized bee of the western montane regions is superficially very much like Andrena vicinoides Viereck but can be separated from the latter by the lack of basal teeth or angles on the mandibles of both sexes; In addition the vertex of both sexes is frequently slightly taller than one ocellar diameter above the lateral ocellus, the male has the tips of the penis valves expanded laterally and flattened at the tips, and the female has a usually flatten, shiny clypeus.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 12-14 mm; width, 3-4 mm; wing length, M = 5.01 ±0.144 mm; FL/FW, M = 0.96±0.008; FOVL/ FOVW, M = 2.71 ±0.035.
INTEGUMENTAL COLOR. — As in vicinoides but often malar space and face adjacent to prostomial suture laterad of subantennal sutures with narrow rufescent zone; wing membranes moderately to deeply infumate, yellow-brown to dark brown.
STRUCTURE. — Antennal scape length equals first two and one-half flagellar segments or slightly more; flagellar segment 1 equal in length to slightly more than segments 2 plus 3; segment 2 about as long as 3 and as broad as long; segments 4-10 slightly longer than broad; Eyes as in vicinoides; Mandible as in vicinoides but lacking basal, inferior tooth or angle; Maxillary palpus as in vicinoides but segmental ratio about as 0.8:1.0:0.8:0.7:0.6:0.5; Labial palpus as in vicinoides but ratio about as 1.0:0.5:0.5:0.4; Clypeus usually slightly flattened apicomedially, with small to moderately coarse, round punctures separated by about half a puncture width, impunctate midline usually complete to base, punctures usually sparse in small area near apex of impunctate line; surface shiny, unshagreened except in basal third or less (usually much less than one-third shagreened); Supraclypeal area, face above antennal fossae and facial fovea as in vicinoides; Vertex as in vicinoides but above lateral ocellus usually slightly taller than one ocellar diameter, never less; Genal area as in vicinoides, Thoracic form and sculpturing as in vicinoides; Wing venation typical for subgenus; second submarginal cell usually longer than tall.
Metasomal terga and sterna and pygidial plate sculptured as in vicinoides; Tergum 2 with apical area short as in vicinoides.
VESTITURE. — Generally as in vicinoides with dark head, metasoma and legs and pale thoracic dorsum; tergum 2 with pale hairs more frequently than in vicinoides and rarely tergum 3 with pale hairs mediobasally; Pollen-collecting hairs as in vicinoides.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 8-12 mm; width, 1.5-2.5 mm; wing length, M = 4.08±0.271 mm; FL/FW, M = 0.95*0.007; FS1/FS2, M = 1.06 ±0.026.
INTEGUMENTAL COLOR. — As in vicinoides but antennal flagellar segments 3-11 often dark reddish-brown below.
STRUCTURE. — Antennae as in vicinoides; Eyes each three times as long as broad or slightly longer; inner margins parallel; Mandible as in vicinoides but without basal inferior tooth; Malar space and galea as in vicinoides; Maxillary palpus as in vicinoides but segmental ratio about as 0.8:1.0:0.7:0.6:0.6:0.6; Labial palpus as in vicinoides but ratio about as 1.0:0.5:0.5:0.4; Labrum as in vicinoides; Clypeus distinctly flattened apicomedially, with moderately coarse round punctures separated by half a puncture width or slightly more except along impunctate midline (often incomplete posteriorly) and small apicomedian area of sparse punctures (occasionally absent); surface shiny, unshagreened except occasionally at extreme base; Supraclypeal area and face above antennal fossae as in vicinoides; Vertex usually tall, above lateral ocellus equals at least one ocellar diameter and usually distinctly more; Genal area as in vicinoides; Thoracic form and sculpturing as in vicinoides but propodeal dorsal enclosure often weakly and irregularly rugulose in basal half or more.
Metasomal terga and sterna with form and sculpturing as in vicinoides; note sternum 6 sharply reflexed across apex.
Terminalia as in figures 147-151.
VESTITURE. — As in vicinoides; rarely tergum 2 with apical area with a few pale hairs laterally.