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 is related to A. scurra and A. mohavensis. It can be separated from females of mohavensis by the less well developed apical abdominal fasciae and the longer hairs on the thoracic dorsum. The males have the light colored maculation restricted to the clypeus, longish hairs on the abdominal terga and wider apex on the gonocoxite. Andrena cruciferarum is distinguished from female scurra by the less distinct punctures on the clypeus and by the smoother and regular shagreening on the propodeum. The male of cruciferarum can be distinguished by the propodeum, bent apex of the gonocoxite and the longer hairs on the abdominal terga.
Andrena cruciferarum is nearly allopatric with mohavensis (Fig. 2) and probably sympatric with scurra. Andrena scurra gets into southern California but is rare there. Perhaps its rarity is due to competition with cruciferarum.
The descriptions below are based mainly upon the holotype and the allotype.
FEMALE. — MEASUREMENTS AND RATIOS. — Length, 9.5 mm; width 2.8 mm; wing length, 7.4 mm; FL/FW, 0.93; FOVL/FOVW, 4.00.
INTEGUMENTAL COLOR. — Black to dark brown otherwise as in scurra except body with metallic luster, hind legs entirely dark.
STRUCTURE. — Antennal scape as long as first four flagellar segments; antenna otherwise as in scurra. Eyes, mandible, galea, stipes and labial palpus as in scurra but ratio about 1.0:0.7:0.7:0.7. Maxillary palpus as in scurra but ratio about 0.6:1.0:0.8:0.6:0.4:0.6. Labrum as in scurra but process small and apex not emarginate. Clypeus as in scurra but punctures moderate in size. Supraclypeal area, face above antennal fossae and vertex as in scurra but moderately dull. Facial fovea narrow, separated from lateral ocellus by one and one-half ocellar diameters. Genal area as in scurra.
Pronotum as in scurra but punctures more scattered. Mesoscutum as in scurra but entire surface moderately dull, punctures obscured by rather coarse reticular shagreening. Scutellum sculptured as mesoscutum. Propodeum with dorsal area triangular with coarse but regular shagreening, basally few rugulae; remainder of propodeum as in scurra but shagreening on dorsolateral and posterior surfaces smoother and regular. Mesepisternum, wings and legs as in scurra.
Metasomal terga 1-4 with weak apicolateral elevations, punctures indistinct. Tergum 5, pygidial plate and sterna as in scurra.
VESTITURE. — Generally white otherwise as in scurra except as follows: facial fovea, hind tibia at base, hind femur at apex, tip of abdomen with brownish hairs; metasomal terga 2-4 with apical white fasciae moderately well developed.
MALE. — MEASUREMENTS AND RATIOS. — Length, 8.5 mm; width, 2.0 mm; wing length, 6.5 mm; FL/FW, 0.94; FS1/FS2, 1.50.
INTEGUMENTAL COLOR. — Black to dark brown with same exceptions as in female but clypeus cream-colored except apex and two small dark spots.
STRUCTURE. — Antenna rather long, reaching propodeum in repose; scape length equal to first two and one-half flagellar segments; flagellar segment 1 as long as segments 2 plus one-third of 3; antenna otherwise as in scurra. Eyes, mandible, galea, stipes and labial palpus as in scurra but ratio about 1.0:0.6:0.4:0.9. Maxillary palpus as in scurra but ratio about 1.0:0.8:1.0:0.9:0.6:0.9. Labrum as in scurra but process wider basally. Clypeus as in female scurra but clypeus flattened in center. Supraclypeal area, face above antennal fossae, vertex and genal area as in female.
Pronotum, mesoscutum, scutellum and mesepisternum as in female. Wings as in female but vein 1st m-cu meets second submarginal cell in basal one-fourth of cell. Legs as in scurra but hind tibia rather slender.
Metasomal terga 1-4 as in female but punctures further apart. Tergum 5 as in scurra. Pygidial plate absent. Sterna 2-5 as in scurra but punctures minute. Sternum 6 as in scurra.
Terminalia as in figures 29-33; note the following: gonocoxite with dorsal lobes long and rather slender, apex rather narrow and emarginate on inner margin; penis valve rather narrow with dorsal lamellae reduced to tiny elongate lobes, apex short, in ventral view thick, broadly rounded, slightly expanded; sternum 7 with large apical notch; sternum 8 twice bent in side view, with apex slightly broader than neck region, with tiny ventral subapical elevation.
VESTITURE. — White otherwise as in scurra except abdominal terga covered with long or moderately long, suberect hairs; apical white fasciae weaker, long scattered hairs at sides on terga 2 and 3, band weaker on tergum 4 but present in center.
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