Reprinted with permission of the American Entomological Society from:
Ribble, D. W. 1974. A revision of the bees of the genus Andrena of the Western Hemisphere. Subgenus Scaphandrena. Transactions of the American Entomological Society 100: 101-189.
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This species can be distinguished from sladeni by the lack of toothed tarsal claws and very narrow facial fovea in the female. Andrena hicksi and bruneri also lack the toothed tarsal claws but these species have all dark hairs and a dark integument. The male of walleyi differs from sladeni by having flagellar segment 2 shorter than segment 3, sternal fimbriae and abdominal punctures smaller and further apart.
The descriptions below are based mainly on a female from Colorado and a male from Smithfield Canyon, Utah.
FEMALE. — MEASUREMENTS AND RATIOS. — Length, 10.6 mm; width, 2.7 mm; wing length, 8.0 mm; FL/FW, 1.15; FOVL/FOVW, 5.67.
INTEGUMENTAL COLOR. — Color as in merriami but most of body with bluish-black luster, on thoracic dorsum luster bluish-green.
STRUCTURE. — Antennal scape about as long as first three and one-half flagellar segments; antenna otherwise as in merriami. Eyes each 4 times as long as broad, inner margins parallel. Mandible as in merriami. Galea as in merriami but longer, moderate in width, more pointed. Stipes with few curved hairs. Labial palpus as in merriami but ratio about 1.0:0. 6:0.4:0.8. Maxillary palpus surpassing galea by about last two segments, segmental ratio about as 0.9:1.0:0.9:0.9:0.7:0.8. Labrum as in merriami. Clypeus as in merriami but shagreening absent on apical half in center. Supraclypeal area and face above antennal fossae as in merriami. Facial fovea very narrow, separated from lateral ocellus by about one and one-half ocellar diameters, not reaching level of lower margins antennal fossae. Vertex as in merriami but height less than one ocellar diameter. Genal area as in merriami.
Mesosoma as in merriami but tarsal claws untoothed.
Metasomal terga 1-4 as in merriami but punctures closer. Tergum 5 as in merriami. Pygidial plate as in merriami but without upturned margins. Sterna 2-5 as in merriami but punctures larger and closer.
VESTITURE. — As in merriami except as follows: head with vertex hairs brownish; thoracic dorsum with white hairs of moderate length; hind tibia with many hairs along anterior margin curved anteriorly.
MALE. — MEASUREMENTS AND RATIOS. — Length, 8.6 mm; width, 2.1 mm; wing length, 5.8 mm; FL/FW, 1.12; FS1/FS2, 2.20.
INTEGUMENTAL COLOR. — Color as in female but luster brighter blue, clypeus cream-colored except apex and two small dark spots.
STRUCTURE. — Scape about as long as first two and one-half flagellar segments; flagellar segment 1 as long as segments 2 plus 3; antenna otherwise as in merriami. Eyes each about 3.4 times as long as broad, inner margins nearly parallel. Mandible and galea as in female. Stipes as in merriami. Labial palpus as in female but ratio about 1.0:0.5:0.5:0.7. Maxillary palpus as in female but ratio about 0.7:1.0:1.0:0.9:0.6:0.9. Labrum and clypeus as in merriami. Supraclypeal area, face above antennal fossae, vertex and genal area as in female.
Pronotum, mesoscutum and scutellum as in female. Propodeum as in female but shagreening on dorsolateral and posterior surfaces slightly coarser and less even. Mesepisternum as in female. Wings as in female but vein 1st m-cu meets second submarginal cell before center of cell. Legs as in merriami.
Metasomal terga 1-4 as in female. Tergum 5 as in female but punctures smaller. Pygidial plate absent. Sterna 2-6 as in merriami.
Terminalia as in figures 75-79; note the following: gonocoxite with dorsal lobes short, broadly rounded, almost truncate, apex moderate in width, inner margins slightly emarginate at apex; penis valve wide, with large, subtriangular dorsal lamellae, apex short, slender in side view; sternum 7 with apex deeply notched; sternum 8 not widened at apex, with apical emargination.
VESTITURE. — As in merriami but most leg and abdominal hairs dark.
VARIATION. — The two females from Grantsville, Utah have a very shiny clypeus, moderate-sized clypeal punctures and apical abdominal fasciae on the sides of terga 2 and 3. The other two females from Utah are intermediate in these characters between the Grantsville females and the other females with more shagreening and larger punctures on the clypeus and without fasciae.
In two of the males the hairs on the legs and abdomen are mostly amber rather than chocolate brown.