Reprinted with permission of the American Entomological Society from:
LaBerge, W. E. 1985. A revision of the bees of the genus Andrena of the Western Hemisphere. Part XI. Minor subgenera and subgeneric key. Transactions of the American Entomological Society 111: 440-567.
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Andrena violae is a distinctive bee of eastern North America and can readily be recognized by the strongly protuberant clypeus; the elongated mouthparts, especially the labial palpi; the short malar space; and the fasciate terga in both sexes. The male is remarkably female-like in general appearance, especially in the short antennae.
FEMALE. MEASUREMENTS AND RATIOS: N = 20; length, 9-11 mm; width, 2.5-3.0 mm; wing length, M = 3.32 ± 0.530mm; FL/FW, M = 1.06 ± 0.006; FOVL/FOVW, M = 3.97 ± 0.063.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical half to three-fourths rufescent; flagellar segments 4-10 yellowish brown below; tegulae rufescent; wing membranes hyaline, yellowish, veins reddish brown; terga 1-5 with narrow apical margins hyaline, colorless; sterna 2-5 hyaline apically, yellow; legs often dark rufescent.
STRUCTURE. — Antennal scape as long as first three and one-third flagellar segments; flagellar segment 1 equal to following two and one-half segments; segment 2 as long as segment 3, as long as broad. Eyes each about three and one-half times as broad, inner margins parallel or diverging toward vertex. Malar space short, linear. Mandibles short, overlapping when closed by about two-fifths mandibular length, bidentate. Galea and glossa elongate, longer than clypeus; galea pointed, surface dulled by coarse, even tessellation. Maxillary palpus extends beyond galea by about last two segments, segmental ratio about 0.7:1.0:1.0:1.0:0.8:0.8. Labial palpus slightly longer than maxillary palpus, segmental ratio about 1.0:1.0:0.8:0.9. Labral process large, flat, weakly emarginate; labrum below process convex, without distinct cristae. Clypeus strongly bowed outward; punctures of irregular size, separated by half to one puncture width, surface moderately dulled by coarse tessellation. Supraclypeal area with minute punctures and fine shagreening dulling surface. Face above antennal fossae with fine longitudinal rugulae, fine tessellation, and small sparse punctures dulling surface. Facial fovea shallow, relatively narrow, separated from lateral ocellus by about one ocellar diameter. Vertex above lateral ocellus equals one ocellar diameter or more, dulled by fine tessellation. Genal area in profile slightly narrower than eye, dulled by minute punctures and fine shagreening except near eye margin.
Pronotum with weak humeral angle and dorsoventral ridge; opaque, dulled by ' fine tessellation. Mesoscutum with small punctures separated mostly by one to two puncture widths, more crowded peripherally, surface dull, tessellate. Scutellum similar. Propodeum with dorsal enclosure dull, densely tessellate; dorsolateral and posterior surfaces similar but with minute sparse punctures; corbicular surface similar but tessellation coarser. Mesepisternum dull, coarsely tessellate with obscure, minute punctures. Wing venation as in subgeneric description.
Metasomal tergum 1 with basal area with small round punctures separated mostly by one to two puncture widths or more, denser basally than near apical area; apical area with punctures more crowded, especially laterally; surfaces shiny, shagreening weak or absent. Terga 2-4 similar, but basal area punctures slightly denser. Pygidial plate described in subgeneric account. Sterna 2-5 with apical areas impunctate, basal areas with minute punctures separated by two or more puncture widths, surfaces dull, tessellate.
VESTITURE. — Pale yellow except as follows: tergum 5 medially golden brown; tarsi with internal surfaces rufescent. Metasomal terga 2-4 with distinct pale apical pubescent fasciae, often narrowly interrupted medially on tergum 2. Pollen collecting hairs as in subgeneric description.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 7-10 mm; width, 1.5-2.5 mm; wing length, M = 3.11 ± 0.132 mm; FL/FW, M = 1.12 ± 0.079; FS1/FS2, M = 2.67 ± 0.060.
INTEGUMENTAL COLOR. — Black with same exceptions as female except clypeus apicomedially and parocular areas often with small yellow maculae; in a few specimens parocular maculae present, but clypeus entirely black; in one specimen median third of clypeus yellow; almost half of specimens without yellow maculae.
STRUCTURE. — Antennae short, female-like; scape about as long as first two and one-half flagellar segments; flagellar segment 1 equals next two and three-fourths segments; segment 2 as long as 3 and about as broad as long; median segments not much longer than broad. Eyes each about three times as long as broad, inner margins diverging toward vertex. Mandibles, malar space, galea, and glossa as in female. Maxillary palpus as in female, but segmental ratio about 0.8:1.0:1.0:0.9:0.7:1.0. Labial palpus as in female, but ratio about 1.0:0.9:0.8:0.8. Labral process, labrum, clypeus, supraclypeal area, face, vertex, and genal areas as in female.
Pronotum as in female. Thoracic sculpturing and wing venation as in female, Metasomal terga 1-5 sculptured as in female terga 1-4. Tergum 7 without pygidial area. Sterna 2-5 sculptured as in female. Sternum 6 with apical margin weakly emarginate, relatively flat. Terminalia as in figures 79-83. Note the elongate and sharply pointed penis valves and apicolateral lobes of the gonocoxite, the short blunt dorsal lobes of the gonocoxites, and the deeply emarginate sternum 7.
VESTITURE. — Color as in female; terga 2-5 fasciate as in female terga 2-4; sterna 2-5 with distinct subapical fimbriae of long straight hairs.
Reprinted with permission from: Mitchell, T.B. 1960. Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141.
FEMALE — Length 9 mm.; face somewhat longer than broad; clypeus protuberant, markedly convex, projecting about one-half below suborbital line, somewhat shining, deeply, rather coarsely and quite uniformly punctate, interspaces about equal to diameter of punctures; facial foveae rather narrow, occupying only slightly more than half of space between eyes and ocelli, covered with pale ochraceous tomentum; space between margin of vertex and lateral ocelli very slightly greater than their diameter; cheeks subequal to eyes in width, rounded posteriorly, somewhat shining, punctures very fine, quite close, more or less obscured by the pubescence; malar space very short; basal segment of flagellum only slightly shorter than 2nd, 3rd and 4th combined; process of labrum very large, broader than long, nearly semicircular; glossa elongate, linear, many times as long as basal width; pubescence of head, thorax and legs, pale ochraceous, somewhat more whitish below; thoracic integument dull, punctures of scutum very fine, rather close anteriorly, becoming more widely separated posteriorly, but not sparse, well separated and quite distinct on the scutellum, which is somewhat shining; pleura with some very shallow and obscure punctures anteriorly, otherwise densely tessellate; dorsal area of propodeum oblique, triangle densely tessellate; propodeal corbicula rather short and poorly developed, without a distinct anterior fringe, pale ochraceous; trochanteral floccus very short and poorly developed; hind tibiae quite narrow, apex only slightly broader than basitarsi, scopa rather dense, hairs simple, of moderate length, entirely pale ochraceous; front and middle basitarsi slightly narrower than their respective tibiae; 2nd submarginal cell somewhat shorter than 3rd, receiving 1st recurrent near middle; abdominal terga smooth and shining, closely, deeply and rather coarsely punctate, apical impressed areas very shallow, occupying medially about one-third length of discs, discal pubescence extremely short and thin, entirely pale, terga 2-4 with conspicuous but rather narrow, whitish, apical fasciae, that on tergum 2 slightly interrupted medially, tergum 5 with a brownish-ochraceous, apical fimbria.
MALE — Length 9 mm.; clypeus strongly convex and protuberant, projecting fully one-half below suborbital line, with one or two small, subapical, yellowish blotches, shining, deeply and distinctly punctate, the punctures moderately coarse, well separated but not sparse; space between margin of vertex and lateral ocelli, considerably broader than their diameter; cheeks slightly broader than eyes, rounded posteriorly, quite dull, punctures very minute and obscure; malar space very short; basal segment of flagellum equaling 2nd, 3rd and 4th combined; Process of labrum very large, broadly semicircular; mandibles rather short, with a distinct, inner, subapical tooth, overlapping about one-fourth; glossa elongate, linear, many times as long as basal width; pubescence of head, thorax and legs entirely whitish-ochraceous; thoracic integument dull, tessellate, punctures of scutum fine and rather shallow, rather close anteriorly, becoming well separated but not sparse posteriorly, irregularly scattered on scutellum, rather sparse medially, surface somewhat shining; pleura obscurely, rather closely and shallowly punctate anteriorly, surface otherwise very densely tessellate; dorsal area of propodeum oblique, triangle rather broad, densely tessellate; basitarsi quite slender and elongate, slightly narrower than their respective tibiae; 2nd submarginal cell somewhat shorter than 3rd, receiving 1st recurrent near middle; abdominal terga smooth and shining, deeply and quite closely punctate, punctures rather coarse, apical impressed areas very shallow and obscure, concolorous with remainder of discs, except for an exceedingly narrow subhyaline rim, discal pubescence very short, thin, erect, entirely pale, terga 2-4 with thin, pale ochraceous, apical fasciae, somewhat interrupted medially on tergum 2; sternum 7 conspicuously bifurcate apically; apical portion of sternum 8 quite broad and robust, slightly narrower toward base than at apex, which is rather broadly rounded and slightly emarginate medially, clothed beneath with thin, pale pubescence; penis valves very slender apically, somewhat broadened toward base, not excavated laterally, gonocoxites very slender to the slightly dilated tips, which are produced to an acute point, gonocoxal lobes not produced. medially, surface somewhat shining; pleura obscurely, rather closely and shallowly punctate anteriorly, surface otherwise very densely tessellate; dorsal area of propodeum oblique, triangle rather broad, densely tessellate; basitarsi quite slender and elongate, slightly narrower than their respective tibiae; 2nd submarginal cell somewhat shorter than 3rd, receiving 1st recurrent near middle; abdominal terga smooth and shining, deeply and quite closely punctate, punctures rather coarse, apical impressed areas very shallow and obscure, concolorous with remainder of discs, except for an exceedingly narrow subhyaline rim, discal pubescence very short, thin, erect, entirely pale, terga 2-4 with thin, pale ochraceous, apical fasciae, somewhat interrupted medially on tergum 2; sternum 7 conspicuously bifurcate apically; apical portion of sternum 8 quite broad and robust, slightly narrower toward base than at apex, which is rather broadly rounded and slightly emarginate medially, clothed beneath with thin, pale pubescence; penis valves very slender apically, somewhat broadened toward base, not excavated laterally, gonocoxites very slender to the slightly dilated tips, which are produced to an acute point, gonocoxal lobes not produced.
DISTRIBUTION — New York to North Carolina, west to Illinois and Colorado; March and April.
FLOWER RECORDS — viola, Potentilla. Robertson (1929) records violae On Cardamine, Ellisia, Oxalis, and three specles of Viola.
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