Reprinted with permission of the American Entomological Society from:
LaBerge, W. E., Ribble, D. W. 1975. A revision of the bees of the genus Andrena of the Western Hemisphere. Part VII. Subgenus Euandrena. Transactions of the American Entomological Society 101: 371-446.
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Andrena suavis is a small Californian species which closely resembles caerulea but differs in that both sexes have distinct apical tergal fasciae and have only subdued metallic blackish-green integument. In addition, the violaceous reflections of the clypeus of both sexes is more or less subdued and the female has narrower, shorter facial foveae more widely separated from the lateral ocelli than in caerulea.
FEMALE. MEASUREMENTS AND RATIOS. — Length, 8-9 mm; width, 2.0-2.5 mm; wing length, M = 3.14 ± 0.131 mm; FL/FW, M = 0.96 ± 0.005; FOVL/EOVW, M = 4.53 ± 0.104.
INTEGUMENTAL COLOR. — With faint metallic greenish luster to black; color otherwise as in caerulea but clypeus with violaceous reflections usually faint.
STRUCTURE. — Antennae as in caerulea except flagellar segment 1 nearly as long as segments 2, 3 and 4 together; segments 4-8 quadrate. Eyes, mandible, galea as in caerulea. Maxillary palpus as in caerulea but segmental ratio about as 0.9:1.0:1.0:0.9:0.6:0.8. Labial palpus as in caerulea but ratio about as 1.0:0.6:0.4:0.9. Labral process often entire or slightly emarginate apically, subrectangular to rounded apically; labrum below process as in caerulea. Clypeus, supraclypeal area, face above antennal fossae as in caerulea. Facial fovea narrow, short, separated from lateral ocellus by about two and one-half ocellar diameters, not extending downwards beyond lower margins of antennal fossae. Vertex and genal area as in caerulea.
Thoracic sculpturing as in caerulea but propodeum outside of enclosure with slightly coarser shagreening. Wing venation as in caerulea; hind wing with vannal lobe narrow, usually about one and one-half times as broad as apical end of cell Cu (lobe measured at base of excision). Hind tibia cuneate as in caerulea.
Metasomal sculpturing and pygidial plate as in caerulea.
VESTITURE. — Generally white with brown hairs on tarsi and hind tibia on and surrounding basal plate; metasomal terga 5 and 6 often with brown hairs; facial fovea with hairs brown to white, usually with abundant dark brown hairs along inner margins compound eyes and on vertex. Terga 2-4 with distinct apical pale fasciae composed of loose, longish hairs, usually interrupted medially on tergum 2.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length. 7-9 mm; width, 1.5-2.0 mm; wing length, M = 2.81 ± 0.118 mm; FL/FW, M = 0.98 ± 0.006; FS1/FS2, M = 1.82 ± 0.037.
INTEGUMENTAL COLOR. — Generally as in female but metallic reflections less evident.
STRUCTURE. — Antennae of moderate length, just reaching metanotum; scape length slightly shorter than first three flagellar segments; flagellar segment 2 broader than long; otherwise as in caerulea. Eyes each about three and one-half times as long as broad, inner margins converging towards mandibles. Mandible and galea as in caerulea. Maxillary palpus as in caerulea but segmental ratio about as 1.0:1.0:1.0:0.9:0.6:1.0. Labial palpus as in caerulea but ratio about as 1.0:0.6:0.4:0.7. Labrum, clypeus, supraclypeal area, face above antennal fossae and facial fovea as in caerulea. Vertex above lateral ocellus short, usually slightly less than one ocellar diameter. Genal area as in caerulea.
Thoracic sculpturing as in caerulea but propodeum and mesepisternum often slightly more coarsely sculptured. Hind wing with vannal lobe narrow, usually no broader at base of excision than neighboring distal end of cell Cu. Metasomal sculpturing and structure as in caerulea. Terminalia as in figures 40-44; note the following: as in caerulea but sternum 7 more deeply emarginate and sternum 8 broader.
VESTITURE. — Color as in caerulea except propodeum without dark hairs and never as dark as in darkest specimens of caerulea. Hairs moderately abundant, long even on metasomal terga 2-4, apical pale fasciae of terga 2-5 weaker than in female and that on tergum 3, as well as on 2, interrupted medially. Sterna 2-5 with subapical fimbriae absent or extremely weak.