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Andrena virginiana Mitchell, 1960
Trachandrena obscura Robertson, 1902; Andrena obscura_homonym (Robertson, 1902); Andrena obscurida Warncke, 1970, replacement name

Life   Insecta   Hymenoptera   Apoidea   Andrenidae   Andrena
Subgenus: Trachandrena



Andrena virginiana, -female, -back 2012-07-11-14.22.49
© Copyright source/photographer · 9
Andrena virginiana, -female, -back 2012-07-11-14.22.49

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Andrena virginiana, -female, -face 2012-07-11-14.33.31
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Andrena virginiana, -female, -face 2012-07-11-14.33.31
Andrena virginiana, female, side 2012-07-11-14.43.17
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Andrena virginiana, female, side 2012-07-11-14.43.17
Andrena virginiana FEM CFP comp
© Copyright Laurence Packer 2014 · 7
Andrena virginiana FEM CFP comp

Andrena virginiana MALE CFP comp
© Copyright Laurence Packer 2014 · 7
Andrena virginiana MALE CFP comp
Andrena virginiana, f on Spiraea --
Michael Veit · 6
Andrena virginiana, f on Spiraea --
Andrena virginiana, f on Spirea
Michael Veit · 6
Andrena virginiana, f on Spirea

Andrena virginiana, -female-back 2012-07 -11-142249
© Copyright source/photographer · 1
Andrena virginiana, -female-back 2012-07 -11-142249
Andrena virginiana, female, face
© Rebekah Andrus Nelson · 1
Andrena virginiana, female, face

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Andrena virginiana – Rare vernal bee in collections. Females noted for vertex greater than one ocelli diameter, T2 basal area closely pitted, vertex with two rows of pits, and scutum with pits separated by 1 to 4 pit diameters. Overall the vertex and scutum are sparsely pitted compared to similar species.

Overview
Reprinted with permission of the American Entomological Society from: LaBerge, W. E. 1973. A revision of the bees of the genus Andrena of the Western Hemisphere. Part VI. Subgenus Trachandrena. Transactions of the American Entomological Society 99: 235-371.

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Andrena virginiana is a summer bee of the northeastern states and eastern Canada. It was first named Andrena obscura Robertson in 1902 and Warncke in 1970 pointed out that this is a junior secondary homonym of a Linnaean species. Warncke renamed Robertson's bee, unaware that there was a prior available name in Mitchell's virginiana.

A. virginiana is closely related to A. miranda, in fact the males are difficult to separate except by dissection of the terminalia. The females of virginiana differ from those of miranda by the more sparsely punctate vertex and mesoscutum and the usually shorter apical areas of terga 2-4. The males of virginiana can be separated from those of miranda by the slightly shorter tergal apical areas and by the vertex having slightly larger and sparser punctures.

FEMALE. MEASUREMENTS AND RATIOS. N = 20; length, 8-10 mm; width, 2.5-3.0 mm; wing length, M = 3.45 0.108 mm; FL/FW, M = 1.02 0.004; FOVL/FOVW, M = 3.66 0.054.

INTEGUMENTAL COLOR. Black except as follows: mandible with apical third to half rufescent; flagellar segments 2-10 dark brown below; tegulae piceous to reddened on summit; wing membranes hyaline, yellowish, veins brownish-black to dark reddish-brown; sterna with apical areas rufescent; distitarsi dark rufescent; tibial spurs testaceous to red.

STRUCTURE. Antennal scape length equal to first three and three-fourths flagellar segments; flagellar segments as in sigmundi but segments 2 and 3 slightly broader than long. Eyes each about three and two-thirds times as long as broad, inner margins parallel. Malar space, mandible and galea as in sigmundi. Maxillary palpus as in sigmundi but segmental ratio about as 1.0:0.9:0.7:0.6:0.5:0.6. Labial palpus as in sigmundi but ratio about as 1.0:0.7:0.5:0.5. Labral process and labrum as in miranda. Clypeus and supraclypeal area as in sigmundi. Genal area in profile about as broad as eye; laterally with distinct, round, crowded punctures, shiny, shagreening absent, without rugulae; ventrally with distinct rugulae converging towards mandibles. Vertex as in miranda but above lateral ocelli with only two distinct rows of coarse punctures (an indistinct or incomplete third row occasionally present), punctures at least as large as mesoscutal punctures and distinctly larger than facial punctures, surface shiny or moderately so. Face above antennal fossae with distinct punctures as in miranda. Facial fovea as in sigmundi but lower narrow portion usually broader than space between fovea and eye margin.

Thorax sculptured as in miranda except as follows: mesoscutum more sparsely punctured, punctures separated irregularly by one-half to four or five puncture widths except peripherally (outside of parapsidal lines punctures crowded); scutellar punctures larger and more crowded; surface moderately shiny, with delicate, fine reticular shagreening. Fore femora angulate as in miranda. Posterior tibial spur normal. Wing venation as in sigmundi.

Metasomal sculpturing as in miranda but terga 2-4 with apical depressed areas shorter, equal in length to basal area medially or somewhat longer but never twice as long. Pygidial plate and sterna as in sigmundi.

VESTITURE. Generally white to pale ochraceous; distribution and form of hairs as in miranda.

MALE. MEASUREMENTS AND RATIOS. N = 20; length, 7.5-10.0 mm; width, 1.5-2.5 mm; wing length, M = 3.15 0.185 mm; FL/FW, M = 1.10 0.005; FS1/FS2, M = 0.90 0.019.

INTEGUMENTAL COLOR. Black with same exceptions as female but wing membranes hyaline and almost colorless, veins dark red, and tergal apical areas rufescent with translucent-red or hyaline apical rims.

STRUCTURE. Antennae short, in repose usually not reaching metanotum; scape length equals first two and one-fourth to two and one-third flagellar segments; flagellar segments as in miranda. Eyes each about three and one-third times as long as broad, inner margins converging slightly towards mandibles. Malar space, mandible and galea as in sigmundi. Maxillary palpus as in sigmundi but segmental ratio about as 1.0:1.0:0.9:0.9:0.6:0.6. Labial palpus as in sigmundi but ratio about as 1.0:0.6:0.5:0.6. Labrum, clypeus and supraclypeal area as in sigmundi. Face above antennal fossae with crowded, round or elongate punctures and delicate shagreening, surface dull. Vertex tall as in miranda, with large punctures separated mostly by half a puncture width or slightly more, punctures at least as large as mesoscutal punctures and distinctly larger than facial punctures. Genal area as in female.

Thoracic sculpturing as in miranda. Wing venation as in sigmundi. Tibial spurs and fore femora normal.

Terga sculptured as in miranda except terga 2-5 with apical areas distinctly shorter than basal areas medially. Sternum 6 emarginate apically. Terminalia as in sigmundi but see figures 28-29.

VESTITURE. Usually white or extremely pale ochraceous; form and distribution of hairs as in miranda.




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 slightly longer than distance between eyes; eyes nearly parallel; foveae broad above, much constricted below, but not abruptly so, this area separated but very slightly from margin of eye; lateral ocelli separated from margin of vertex by nearly twice their diameter; cheeks very slightly broader than eyes; clypeus rather short, projecting but slightly below suborbital line, shining between deep, distinct but rather fine and close punctures, but with a median impunctate line; face below ocelli coarsely, deeply and quite closely punctate, punctures on vertex scattered and irregular, quite sparse, surface shining; cheeks with fine, close but rather deep punctures; malar space hardly evident; process of labrum short, subtruncate, with rather broad base, tip not emarginate; basal segment of flagellum slightly shorter than segments 2 and 3 combined, median segments about as long as broad; pubescence short, entirely pale on head and thorax, more whitish below, becoming very slightly cream-colored above, rather dense around antennae, on cheeks below and on thorax laterally; scutum and scutellum shining, punctures deep and distinct, well separated on scutum anteriorly, becoming rather sparse posteriorly, those on scutellum much closer and somewhat more coarse; pleura rather coarsely rugoso-punctate anteriorly, becoming rather smooth posteriorly; dorsal area of propodeum coarsely striate, rather short, lateral areas more reticulate, propodeal corbicula short but rather dense, interior with a few scattered erect hairs but without a distinct anterior fringe; trochanteral floccus quite short; legs dark, basitarsi quite slender, pubescence entirely whitish. hind tibiae quite slender and narrow, scopal hairs rather short and quite dense; spurs pale testaceous; wings subhyaline basally, becoming very faintly infuscated apically, veins and stigma more piceous, 2nd submarginal cell not more than half as long as 3rd, receiving 1st recurrent slightly beyond middle; tegulae piceous anteriorly, more testaceous posteriorly, outer margin narrowly yellowish-hyaline; abdominal terga shining between close, deep and distinct punctures, these quite uniformly distributed, somewhat more widely separated on basal tergum, terga 2-4 impressed for about half the median length, these areas becoming somewhat reddened toward rims, with apical, dense, white fasciae evident laterally, this nearly complete on segment 4, apical fimbria more brownish.



TYPE - Holotype: Female, Barcroft, Va., June 17, 1917 (W. L. McAtee, on Ceanothus americanus). Paratypes: 2 FF, topotypical, [all U.S.N.M.]




Described using the synonymous name: Andrena obscura (Robertson)



FEMALE. Length 9 mm.; clypeus slightly convex, projecting hardly more than one-fourth below suborbital line, with a narrow and indistinct, median, impunctate line, otherwise quite deeply, closely and coarsely punctate, the punctures becoming almost crowded at extreme sides; facial foveae broad above, occupying most of space between eyes and ocelli, covered with white tomentum, abruptly constricted below, this part hardly more than one-half width of the upper part; space between margin of vertex and lateral ocelli subequal to distance between them; cheeks somewhat broader than eyes, rounded posteriorly, rather dull, quite deeply, closely and finely punctate, punctures becoming very sparse above and on lateral portions of vertex; malar space very short; basal segment of flagellum subequal to 2nd and 3rd combined; process of labrum broadly semicircular or subtruncate; pubescence of head and thorax very short, sparse, whitish, faintly tinged with yellow above, that on legs entirely whitish; scutum somewhat shining, deeply and rather coarsely punctate, the punctures rather close along narrow anterior margin, otherwise sparse and irregularly scattered, those on scutellum slightly more coarse and close, the surface shining; pleura coarsely rugose; dorsal area of propodeum oblique, triangle short and very broad, coarsely and rather regularly striate; propodeal corbicula short and poorly developed, without a distinct anterior fringe, whitish; trochanteral floccus white, short and poorly developed; hind tibiae slightly broadened apically, apex not nearly twice width of basitarsi, scopa quite dense, hairs short, entirely simple, white; front and mid basitarsi very slightly narrower than their respective tibiae; 2nd submarginal cell considerably shorter than 3rd, receiving 1st recurrent slightly beyond middle; abdominal terga shining between deep, distinct, rather fine but close punctures, apical impressed areas shallow but quite broad, occupying medially more than half length of disc, becoming faintly reddened along rims, discal pubescence very short, sparse and obscure, apparently entirely pale, terga 2-4 with white apical fasciae, rather well developed laterally, but broadly interrupted medially, tergum 5 with a pale brownish, apical fimbria.



DISTRIBUTION. Illinois, Michigan and New Brunswick, south to North Carolina; July and August.



FLOWER RECORDS. Ceanothus. Recorded by Robertson (1929) on Pycnanthemum flexuosum. Brittain & Newton recorded this species on a number of spring-flowering plants, including Malus, Salix and Vaccinium and it is suspected that they were incorrect in the identification. The record of collection on Ceanothus was made in McDowell Co., N. C. in August.

Names
Scientific source:
Hosts · map
FamilyScientific name @ source (records)
Apiaceae  Daucus carota @ CUIC_ENT (1)
Asteraceae  Solidago sp @ CUIC_ENT (1)
Caryophyllaceae  Stellaria pubera @ AMNH_BEE (1)
Fabaceae  Melilotus officinalis @ CUIC_ENT (1)
Rhamnaceae  Ceanothus americanus @ AMNH_BEE (4)
Rosaceae  Rosa carolina @ CUIC_ENT (1)

Rubus sp @ CUIC_ENT (1)

Spiraea latifolia @ CUIC_ENT (11)

Spiraea sp @ CUIC_ENT (2)

Spiraea @ CUIC_ENT (1)
Tamaricaceae  Tamarix @ AMNH_BEE (1)

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Updated: 2024-10-31 22:53:30 gmt
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