Reprinted with permission of the American Entomological Society from:
Bouseman, J. K., LaBerge, W. E. 1978. A revision of the bees of the genus Andrena of the Western Hemisphere. Part IX. Subgenus Melandrena. Transactions of the American Entomological Society 104: 275-390.
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Andrena carlini is a large bee, conspicuous in the vernal and early summer bee fauna of eastern North America. The female is black with white or pale ochraceous thoracic dorsum and the male is similarly colored although somewhat paler. The female is marked by a distinct median clypeal impunctate line with crowded punctures on either side, a broad pygidial plate, relatively sparsely punctate terga, and an entire, rounded labral process. The male has a relatively long clypeus which is dulled by crowded punctures, the sixth sternum somewhat produced apicomedially with relatively short apical hairs, terga relatively sparsely punctate, and moderately long antennae.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 11-14 mm; width, 3.0-4.5 mm; wing length, M = 4.96 ± 0.117 mm; FL/FW, M = 1.01 ± 0.004; FOVL/FOVW, M = 3.71 ± 0.065.
INTEGUMENTAL COLOR. — Black except as follows; mandible with apical half rufescent; flagellum dark reddish-brown below; wing membranes moderately infumate, yellowish-brown; veins dark brown to black; distitarsi and tibial spurs rufescent.
STRUCTURE. — Antennal scape as long as first three and one-half flagellar segments or slightly longer; flagellar segment 1 distinctly shorter than segments 2 plus 3, segment 2 shorter than 3 and quadrate, segments 3-10 longer than broad. Eyes each three and three-fourths times as long as broad or slightly longer, inner margins parallel to diverging extremely slightly toward mandibles. Mandible moderately long, when closed extending beyond middle of labrum by one-fourth mandibular length; with subapical tooth. Malar space with minimum length equal to about one-fifth basal mandibular width. Galea pointed, broad near base, outer margin gently concave in apical half; punctures minute sparse; stipes with abundant punctures and shagreening dulling surface, punctures concentrated in lower half. Maxillary palpus long, extending beyond tip of galea by last two segments or more, segmental ratio about as 1.0:1.0:1.0:0.9:0.7:0.6. Labial palpus with long, curved first segment flattened apically; segmental ratio about as 1.0:0.7:0.6:0.5. Labral process large, entire, apical margin rounded, width at base equals more than half width of labrum; labrum apical to process with a pair of subapical transverse shiny sulci separated by a median crista, space between sulci and process with abundant piliferous punctures. Clypeus shiny, with abundant coarse punctures separated largely by half to one puncture width, somewhat irregular in size, with distinct median impunctate line. Supraclypeal area dulled by minute close-set punctures often forming minute longitudinal rugulae. Face above antennal fossae with fine longitudinal rugae reaching ocelli and between lateral ocellus and facial fovea, with small indistinct, interrugal punctures. Facial fovea large, shallow, extending below to a line below posterior margin of clypeus, separated from lateral ocellus by about three-fourths an ocellar diameter. Vertex above lateral ocellus equal to one and one-half ocellar diameters or slightly more, surface dulled by fine tessellation and abundant punctures. Genal area in profile about one and one-half times as broad as eye, surface dulled by fine reticular shagreening except narrow area along margin of eye, punctures minute, sparse.
Pronotum without angle, dulled by dense reticular shagreening. Mesoscutum opaque, reticularly shagreened with small obscure punctures separated mostly by one puncture width or more. Scutellum similar but often shagreening less dense and moderately shiny. Metanotum opaque, densely punctate and shagreened. Propodeum with dorsal enclosure evenly rounded (not abruptly declivous posteriorly), surface dulled by coarse tessellation, often rugulose or punctatorugose basally; dorsal surface outside of enclosure and posterior surface dulled by coarse tessellation and small punctures separated largely by one puncture width or more; lateral surface dulled by coarse reticular shagreening, posterior third with fine vermiculate rugulae. Mesepisternum finely tessellate, dull, punctures small, obscure, separated mostly by one or more puncture widths. Wing with pterostigma broad; vein first m-cu meets second submarginal cell near middle or slightly beyond.
Terga 1-4 with depressed apical areas equal to slightly less than half median length of each tergum; basal areas with small punctures separated mostly by one puncture width becoming sparser towards apical area on each tergum; apical areas punctate only in basal half or slightly more, punctures small, relatively sparse; each tergum reticularly shagreened at extreme base, shagreening becoming less distinct towards apex, apical areas shiny, or terga entirely shiny, shagreening weak. Pygidial plate broad, V-shaped with broad, rounded apex and weakly raised internal triangle. Sterna 2-5 moderately shiny, reticulotransversely shagreened; impunctate basally, with small punctures becoming crowded in a subapical line; apical areas impunctate.
VESTITURE. — Black to dark brown except as follows: dorsum of thorax pale ochraceous; occasionally upper third to half of mesepisterna pale ochraceous; facial fovea pale brown at least in lower half; hind femur with long dorsal hairs occasionally pale brown; hind tibial scopal hairs usually black, rarely brown. Pollen-collecting hairs typical for subgenus; tibial scopal hairs long, simple, dense. Terga without apical fasciae.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 10-14 mm; width, 2-4 mm; wing length, M = 4.21 ± 0.148 mm; FL/FW, M = 0.92 ± 0.004; FS1/FS2, M = 1.10 ± 0.017.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical third rufescent; flagellum dark reddish-brown below; wing membranes slightly infumate, yellowish, veins dark reddish-brown to black; terga with apical areas occasionally slightly reddened; sterna dark rufescent; distitarsi dark rufescent; tibial spurs rufescent to testaceous.
STRUCTURE. — Antennae of moderate length, in repose not reaching middle of scutellum; scape length equals first two and one-half flagellar segments or slightly more; flagellar segment 1 as long as segment 2 to slightly longer and as long as segment 3; all segments longer than broad and median segments about one and one-half times as long as broad. Eyes each about three and two-thirds times as long as broad, inner margins diverging slightly towards mandibles. Mandibles decussate, when closed extending two-fifths or more beyond midlabrum. Galea as in female. Maxillary palpus as in female but segmental ratio about as 0.9:1.0:0.9:0.9.0.8:0.9. Labial palpus as in female but ratio about as 1.0:0.6:0.6:0.6. Labral process large, entire or minutely emarginate, rounded apically to trapezoidal with rounded apical angles, much as in female but longer and shinier; labrum apical to process without transverse sulci, often with weak median crista. Clypeus short, but median length slightly more than one-third minimum interocular facial width; surface dulled by crowded coarse punctures and fine interpunctural shagreening, rarely with median impunctate shiny spot. Supraclypeal area as in female. Face above antennal fossae as in female but duller, rugae less regular and punctures more evident. Vertex as in female but above lateral ocellus equal to two ocellar diameters or almost. Genal area broad, in profile equal to one and three-fourths times eye width, sculptured as in female.
Pronotum, mesoscutum and scutellum as in female. propodeum with dorsal enclosure as in female; dorsal and posterior surfaces as in female but punctures more evident; lateral surfaces coarsely tessellate, with sparse but distinct punctures. Mesepisterna and wing venation as in female.
Metasomal terga 1-5 as in female terga 1-4 but basal areas with punctures smaller and sparser, shagreening usually coarser; apical areas with punctures minute and extremely sparse, shiny. Tergum 7 with shiny pygidial area with rounded apex, usually covered by hairs except in narrow median area. Sterna 2-5 impunctate basally, with crowded punctures in transverse subapical row; surfaces moderately dulled by reticulotransverse shagreening. Sternum 6 with apical margin rounded, with large mediobasal impunctate triangular area slightly raised, depressed apical area minutely punctate.
Terminalia as figured (Figs. 12-17); penis valve broadened at base, note twisted gonostylus and form of sternum 8 (typical of carlini group of Melandrena).
VESTITURE. — Pale ochraceous to ochraceous except as follows: vertex, face alongside of compound eyes and genal areas with abundant long dark brown to black hairs; terga 3-5 or 2-5 with basal areas with sparse erect dark brown to black hairs at least in part. Terga without apical pale fasciae; sterna 2-5 without distinct subapical fimbriae; sternum 6 with sparse relatively short hairs directed posteriorly in apical depressed area. Leg hairs pale.
Reprinted with permission from: Mitchell, T.B. 1960. Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141.
Described under the subspecific name: Andrena carlini carlini Cockerell
FEMALE. — Length 14 mm.; clypeus strongly convex, protruding considerably below suborbital line, with a slightly elevated, median, impunctate line, otherwise rather finely punctate, punctures well separated but not sparse; facial foveae broad above, nearly filling area between eyes and lateral ocelli, covered with fuscous tomentum; space between margin of vertex and lateral ocelli about equal to distance between the ocelli; cheeks slightly broader than eyes, rather dull, very obscurely and minutely punctate; malar space extremely short; basal segment of flagellum subequal to 2nd and 3rd combined; process of labrum very large, fully twice as broad as long, evenly rounded; mandibles of moderate length, with a small, inner, subapical tooth; pubescence of head entirely blackish or fuscous; thoracic integument dull and tessellate, very finely, closely and rather obscurely punctate; enclosure of propodeum somewhat roughened along basal margin; pubescence of scutum, scutellum and upper portion of propodeum pale ochraceous or whitish, that on pleura, propodeum laterally and legs entirely black; propodeal corbicula well developed, blackish, with a distinct anterior fringe; trochanteral floccus well developed, black: tibial scopa dense, black, of simple hairs; fore and hind basitarsi slightly narrower than their tibiae, the mid basitarsi nearly as broad as their tibiae; 2nd submarginal cell nearly as long as 3rd, receiving 1st recurrent just beyond middle; abdominal terga somewhat shining, apical margins, slightly depressed, depressed area equal to about one-third length of the plates medially, concolorous with remainder of discs which are finely and rather closely punctate basally, becoming more sparsely so apically and on depressed apical areas, pubescence short, erect, entirely black, fasciae lacking.
MALE. — Length 11 mm.; clypeus slightly convex, projecting hardly at all below suborbital line, quite closely and finely punctate beneath the dense pubescence; distance between margin of vertex and lateral ocelli about equal to distance between the ocelli; cheeks somewhat broader than eyes, rather dull, very minutely punctate, hind margin rounded (as in hilaris, fig. 21); malar space extremely short; basal segment of flagellum barely equaling 2nd segment in length; process of labrum very large; occupying most of surface of labrum, broadly rounded; mandibles slender, slightly curved, with a distinct, subapical, inner tooth, overlapping about one-third; pubescence of head long and copious, white on face, vertex and on cheeks below, fuscous along inner margin of eyes and on cheeks above; thoracic integument dull and tessellate, finely, shallowly and rather closely punctate; enclosure of propodeum narrowly roughened along basal margin; pubescence of entire thorax and legs whitish, quite long and copious; all basitarsi slender and elongate, much narrower than their respective tibiae; 2nd submarginal cell slightly shorter than 3rd, receiving 1st recurrent at center; abdominal terga somewhat shining, rather narrowly depressed apically, discs finely and rather closely punctate except for the almost impunctate depressed areas, pubescence short, erect, pale toward base, becoming somewhat fuscous toward apex, fasciae entirely lacking; sternum 8 rather short, sides of apical portion nearly parallel, the tip rounded or obtusely pointed, with a pronounced ventral projection which is about as long as the remainder of the apex, area between these two parts densely pubescent; penis valves bulbous basally, sides not excavated, gonocoxites rather broadly dilated apically, the gonocoxal lobes somewhat produced, markedly triangular.
DISTRIBUTION. — Minnesota and Ontario, east to the New England states and Nova Scotia, south to Missouri, Georgia and North Carolina; March to August.
FLOWER RECORDS. — Amelanchier, Brassica, Malus, Pyrus, Rubus, Vaccinium and Vicia. Robertson (1929) records carlini on the following additional genera: Anemonella, Arabis, Cercis, Chaerophyllum, Claytonia, Cornus, Dentaria, Dicentra, Erigenia, Erythronium, Hepatica, Heracleum, Hydrophyllum, Isopyrum, Polemonium, Rhus, Ribes, Salix, Sanguinaria, Sassafras, Smilacina, Thaspium, Uvularia, Viburnum and Viola. According to Brittain and Newton (1933 & 1934) carlini also visits Prunus, Solidago, Tragana and Trifolium.
Described under the subspecific name: Andrena carlini neorhodura
MALE. — Agrees with typical carlini in all details except the entirely bright ferruginous or testaceous abdomen.
TYPES. — Holotype: Male, Minot County, Mass. [M.C.Z.]. Paratypes: 1 M, East Lansing, Mich., April 12, 1938 [Univ. Mich.]; 2 MM, State College, Pa., May 2, 1916 and April 1, 1922 (both S. W. Frost) [Penn. State Univ.].