Reprinted with permission of the American Entomological Society from:
LaBerge, W. E., Ribble, D. W. 1972. A revision of the bees of the genus Andrena of the Western Hemisphere. Part V: Gonandrena, Geissandrena, Parandrena, Pelicandrena. Transactions of the American Entomological Society 98: 271-358.
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Andrena integra is a small eastern forest species somewhat more northerly in distribution than A. fragilis. The female of integra differs from that of fragilis by its smaller labral process which is simple, Hat, rounded apically or trapezoidal in shape. The female is distinctive in the almost bare thoracic dorsum, the vestiture being reduced to sparse, minute, largely simple, closely appressed hairs with a few to several normal long hairs interspersed. The males differ from those of fragilis by the almost complete lack of a clypeal apical emargination, the presence of a subapical fimbria on sternum 2 as well as sterna 3 to 5, and the dark antennae. The male differs from other species of Gonandrena by the virtual lack of clypeal punctures and the lack of tergal apical pale fasciae.
An interesting morphological feature of A, integra is the high incidence of specimens with two submarginal cells in one or both wings, especially in the males. Only one female out of 20 (5%) has two submarginal cells in both wings. In the male 7% had two submarginal cells in both wings and 18.6% had two cells in one wing (about half with the right wing and half with the left wing so formed).
FEMALE. MEASUREMENTS AND RATIOS: N = 20; length, 8-10 mm; width, 2.5-3.0 mm; wing length, M = 3.56 ± 0.157 mm; FL/FW, M = 1.03 ± 0.004; FOVL/FOVW, M = 4.87 ± 0.088.
INTEGUMENTAL COLOR. — As in fragilis except as follows: flagella dark brown to black; wing veins yellow to red except dark brown pterostigma; terga with apical areas piceous or only narrowly hyaline and infumate apically.
STRUCTURE. — Antennal scape length equals about first four and one-fourth flagellar segments; flagellar segment 1 as long as 2 plus 3 and half of 4; otherwise as in fragilis. Eyes each about three and three-fourths times as long as broad, inner margins parallel. Mandible and galea as in fragilis. Labial palpus as in fragilis but ratio about as 1.0:0.5:0.3:0.5. Maxillary palpus as in fragilis but ratio about as 1.0:1.0:0.7:0.7:0.6:0.6. Labral process large, flat, apical margin rounded or trapezoidal in shape; labrum apical to process shiny, with weak transverse sulcus (weak especially medially). Clypeus rounded from side to side, with small round punctures separated by one to four or five puncture widths, broadly impunctate medially, surface dull, tessellate. Supraclypeal area and face above antenna! fossae as in fragilis. Facial fovea as in fragilis but slightly longer, extending down below level of lower margins antennal fossae. Genal area as in fragilis but more dulled by reticular shagreening and posterior carina not as sharp and tending to be lacking below.
Pronotum as in fragilis but with a more distinct dorsoventral ridge and a few to several minute rugulae paralleling ridge and curving posteriad ventrally. Mesoscutum with sparse minute punctures separated mostly by two to four puncture widths or more, surface moderately dull, regularly and finely shagreened. Scutellum and propodeum as in fragilis. Mesepisternum with a weak, longitudinal, rounded ridge extending forwards from top of mesocoxa; above this ridge, surface flat or depressed, roughened by scattered, raise punctures and irregular tessellation. Wing venation as in fragilis but second submarginal cell usually narrower and 1st m-cu meets this cell near outer sixth or less (often less than a vein width to outer margin of cell).
Metasomal tergum 1 as in fragilis. Terga 2-4 with basal areas with extremely minute, sparse punctures, often appearing impunctate except under high magnification, surfaces shiny or slightly dulled by transversely reticular shagreening; apical areas similar to basal. Pygidial plate and sterna 2-5 as in fragilis.
VESTITURE. — As in fragilis except as follows: clypeus and frons above antennal fossae with hairs short and sparse; mesoscutum with most hairs extremely minute, almost branchless, closely appressed and with several long, erect, plumose hairs scattered over surface; terga with apical pale bands absent or greatly reduced; scopal hairs weakly plumose throughout.
MALE. MEASUREMENTS AND RATIOS: N = 20; length, 7-8 mm; width, 1.5-2.0 mm; wing length, M = 3.03 ± 0.141 mm; FL/FW, M = 1.05 ± 0.007; FS1/FS2, M = 1.97 ± 0.037.
INTEGUMENTAL COLOR. — Generally as in female.
STRUCTURE. — Antennae moderately long, reaching metanotum in repose; scape length equal to first two and one-half flagellar segments or slightly more; flagellar segment 1 slightly shorter than segments 2 plus 3, otherwise as in fragilis. Eyes each about three times as long as broad, inner margins parallel or converging slightly towards mandibles. Galea as in female. Mandible as in fragilis. Labial palpus as in fragilis but ratio about as 1.0:0.7:0.4:0.6. Maxillary palpus as in fragilis but ratio about as 1.0:1.0:0.8:0.8:0.6:0.6. Labrum and process as in fragilis. Clypeus as in fragilis but apical margin not deeply emarginate but barely so and surface almost impunctate, punctures minute, sparse, visible only under high magnification, surface dulled by dense tessellation. Supraclypeal area, face, vertex and genal area as in fragilis but genal area usually duller, with dense reticular shagreening and minute short rugulae associated with minute sparse punctures.
Pronotum as in fragilis. Mesoscutum, scutellum and propodeum as in fragilis. Mesepisternum as in female but lacking angular ridge above mesocoxa. Wing venation as in female. Metasomal and sterna sculptured as in female; sternum 6 as in fragilis.
Terminalia as in figures 15-19; note the following: essentially as in fragilis but penis valves with ventral lamellae not as large as dorsal lamellae.
VESTITURE. — Generally as in female hut hairs less abundant; lacking pollen-collecting hairs; mesoscutal hairs all long and barbed; terga 2-5 lacking apical pale fasciae or these reduced to short lateral fasciae; sterna 2-5 with subapical fimbriae of long 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.; clypeus convex, projecting nearly one-half below suborbital line, rather dull, microscopically tessellate, punctures fine, very sparse medially, becoming somewhat closer toward extreme sides; facial foveae very narrow, occupying above less than half of space between eyes and ocelli; space between margin of vertex and lateral ocelli subequal to their diameter; cheeks slightly broader than eyes, rounded posteriorly, the margin subcarinate, surface rather dull, punctures exceedingly minute, close and obscure; malar space extremely short; basal segment of flagellum subequal to 2nd and 3rd combined; process of labrum rather abruptly constricted at base, resulting apical portion subquadrate, truncate apically; pubescence of head and thorax very short and sparse, entirely pale, that on legs also largely or entirely pale; thoracic integument rather dull, punctures of scutum exceedingly minute and obscure, rather widely separated over most of disc, which is somewhat shining posteriorly, those on scutellum exceedingly minute, nearly absent on each side of a median punctate line, surface polished, pleura somewhat protuberant at sides below and just below wing base, surface above finely roughened or subrugose, punctures inevident; dorsal area of propodeum nearly horizontal, triangle rather coarsely rugoso-striate; propodeal corbicula short, poorly developed, without an anterior fringe, pale ochraceous; trochanteral floccus long and well developed, whitish; hind tibiae very slender, apex hardly wider than basitarsi, scopa rather dense, of elongate simple hairs, entirely pale ochraceous; front and middle basitarsi slightly narrower than their respective tibiae; 2nd submarginal cell much shorter than 3rd, receiving 1st recurrent almost at apex; abdominal terga polished, very minutely and quite sparsely punctate, punctures barely visible, apical impressed areas quite shallow but rather narrow, becoming obscurely reddish-hyaline along rims, discal pubescence extremely sparse, short and thin, entirely pale, apical fasciae not developed, tergum 5 with a brownish-ochraceous, apical fimbria.
MALE — Length 8 mm.; head broader than thorax; eyes slightly divergent below; clypeus very broad, rather flat medially, much narrowed apically, projecting about one-half below suborbital line, somewhat shining medially where the punctures are very fine and quite sparse, becoming close at extreme sides where surface is rather dull; space between margin of vertex and lateral ocelli considerably broader than their diameter, cheeks very broad, more or less rounded posteriorly, posterior margin with a conspicuous carina which extends across vertex to reach upper end of eye, surface shining, punctures exceedingly minute, obscure and quite sparse; malar space very short; basal segment of flagellum slightly shorter than 2nd and 3rd combined; process of labrum rather small, markedly protuberant, obscurely semicircular; mandibles rather elongate, inner subapical tooth located about one-fourth of length from tip, rather strongly bowed, overlapping about one-third; pubescence of head, thorax and legs entirely whitish, faintly tinged with ochraceous; thoracic integument dull, quite densely tessellate, punctures of scutum exceedingly obscure, hardly visible, scutellum shining, with more distinct but rather widely scattered punctures; pleura without visible punctures; dorsal area of propodeum oblique, triangle finely tessellate; basitarsi slender and elongate, considerably narrower than their respective tibiae; 2nd submarginal cell considerably shorter than 3rd, receiving 1st recurrent about one-third from apex; abdominal terga smooth, rather dull, microscopically tessellate, punctures hardly visible, apical impressed areas shallow and quite narrow, not conspicuously hyaline along rims, discal pubescence extremely short, sparse and thin, apparently entirely pale, terga 2-4 with thin, whitish, apical fasciae evident laterally, apical margin of sternum 6 rather strongly reflexed; apical portion of sternum 8 narrowest medially, slightly broadened basally and apically, the apex truncate, very slightly emarginate, clothed beneath with rather short, pale pubescence; penis valves very slender and elongate, only very slightly broadened toward base, gonocoxites gradually and slightly dilated to the rounded apex, gonocoxal lobes hardly at all produced.
DISTRIBUTION — Minnesota to Quebec and the New England states, south to North Carolina and Georgia; May to September.
FLOWER RECORDS — Ceanothus and Cornus.
Cockerell (1906) considered lineata Provancher a synonym of integra, but in the Catalog of Hymenoptera (Muesebeck, et.al., 1951, p. 1066), lineata is given as a synonym of fragilis Smith. The type of fragilis is a male, that of integra a female, but the other sex in each is well known and there seems to be no question regarding the correctness of the association of the sexes in these two species. Both of these types have been studied by the writer, as also the type of lineata, and it is his conviction that Cockerell was correct, and that lineata is synonymous with integra.