Reprinted with permission of the American Entomological Society from:
LaBerge, W. E. 1989. A revision of the bees of the genus Andrena of the Western Hemisphere. Part XIII. Subgenera Simandrena and Taeniandrena. Transactions of the American Entomological Society 115: 1-56.
Please report text errors to: leah at discoverlife dot org.
This small west-coast species has relatively simple clypeal hairs as in A. pensilis, but the hairs are short and often have minute, scarcely visible barbs. However, the median clypeal hairs are not highly plumose as in other species and do not hide the clypeal surface. A. orthocarpi females have the clypeal surface dulled by shagreening and shallow punctures, in contrast to the shiny clypeus of pensilis females. The male of orthocarpi is small, has terga 3-5 without apical pale bands, flagellar segment 1 about as long as segment 2 and shorter than segment 3, and has vein r of the fore wing usually very short as in the subgenus Micrandrena.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 7-8 mm; width, 2.0-2.5 mm; wing length, M = 2.84 ± 0.139 mm; FL/FW, M = 0.93 ± 0.005; FOVL/FOVW, M = 2.74 ± 0.040.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical half rufescent; flagellum below dark brown; wing membranes hyaline, veins brown to dark brown; pterostigma usually dark; metasomal tergal apices translucent dark reddish brown to black; tibial spurs testaceous.
STRUCTURE. — Antennal scape as long as first four flagellar segments or slightly longer; flagellar segment 1 about as long as segments 2 and 3 or slightly longer; segment 2 and 3 subequal in length, broader than long; median segments quadrate and longer than segment 3. Eyes, malar space, mandibles, and galea as in nasonii. Maxillary palpus as in nasonii but segmental ratio about as 1.0:1.0:0.8:0.7:0.7. Labial palpus as in nasonii but ratio about as 1.0:0.4:0.4:0.4. Labral process rounded apically or triangular with blunt apex; surface shiny; labrum without cristae. Clypeus moderately flattened, surface with small rounded punctures separated mostly by one or more puncture widths, obscured by coarse shagreening. Supraclypeal area opaque, tessellate. Face above antennal fossae as in nasonii. Facial fovea broad, shallow, separated from lateral ocellus by about one and one-third ocellar diameters. Vertex above lateral ocellus equals about one ocellar diameter. Genal area as in nasonii.
Pronotum as in nasonii. Mesoscutum with punctures minute, separated mostly by two to four puncture widths or more, surface dull, tessellate. Scutellum tessellate, punctures sparse, minute. Propodeum with lateral lines raised but less so than in nasonii; dorsal enclosure tessellate, with fine irregular rugulae roughening surface especially basally; lateral surface coarsely tessellate. Fore wing with vein r short, usually as long as one to three veins widths.
Metasomal tergum 1 with basal area punctate, punctures separated by half a puncture width or less basally, sparser near apical area, surface dulled by fine reticular shagreening; apical area impunctate, finely shagreened, slightly shiny. Metasomal terga 2-4 with basal areas impunctate, reticularly shagreened; apical areas shagreened but often moderately shiny. Pygidial plate flat, without raised internal triangular area, surface coarsely tessellate; apex rounded. Sterna 2-5 as in nasonii.
VESTITURE. — White to ochraceous. Tibial scopal hairs usually brown on basitibial plate and along posterior margin; short and simple as in nasonii. Propodeum with corbiculum complete. Trochanteral 1'locculus complete, small. Metasomal terga 2-4 with pale apical fasciae interrupted medially on tergum 2 and narrowly so on tergum 3.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 5-7 mm; width, 1-2 mm; wing length, M = 2.62 ± 0.130 mm; FL/FW, M = 0.91 ± 0.004; FS1/FS2, M = 1.06 ± 0.029.
INTEGUMENTAL COLOR. — As in female except as follows: mandible with apical third or less rufescent; wing veins usually reddish brown; metasomal terga with apical areas occasionally yellowish brown.
STRUCTURE. — Antennae as in nasonii. Mandible, malar space and galeae as in female. Maxillary palpus as in female but segmental ratio about as 1.0:1.0:0.7:0.7:0.5. Labial palpus as in female. Labral process usually entire, trapezoidal or rounded apically, shiny, two to two and one-half times as long as broad, rarely slightly indented medially along apical margin. Clypeus dull, opaque, reticularly shagreened, punctures obscure. Supraclypeal area and face above antennal fossae as in nasonii. Vertex as in female. Genal area as in nasonii.
Pronotum as in female. Thoracic sculpturing as in female but mesoscutum with punctures extremely sparse or absent; propodeal dorsal enclosure with extremely fine reticular rugulae appearing like coarse tessellation. Metasomal sculpture as in female but tergum 1 not punctate basally and sterna 2-5 with basal area punctures sparse; sternum 6 flat, shallowly emarginate apically. Terminalia as in Figures 27-31.
VESTITURE. — White to pale ochraceous. Clypeus with abundant long plumose hairs often hiding surface. Metasomal terga 2-5 with apical pale fasciae absent or reduced to short lateral fasciae of short, weakly plumose hairs. Sterna without subapical fimbriae.