|
80x5 -
240x3 -
240x4 -
320x1 -
320x2 -
320x3 -
640x1 -
640x2
Set display option above.
Click on
images to enlarge. |
Michael Veit · 6
Andrena erythrogaster, f |
Michael Veit · 6
Andrena erythrogaster, f |
|
Michael Veit · 6
Andrena erythrogaster, f on Sali -- |
Michael Veit · 6
Andrena erythrogaster, m on Sali -- |
|
Michael Veit · 6
Andrena erythrogaster, m on Sali -- |
© USDA Bee Biology and Systematics Laboratory, Logan Utah
· 1
Andrena erythrogaster, 194352, female, subgenal coronet with long plumose hairs |
|
© USDA Bee Biology and Systematics Laboratory, Logan Utah
· 1
Andrena erythrogaster, female, tergal color variability |
© USDA Bee Biology and Systematics Laboratory, Logan Utah
· 1
Andrena erythrogaster, female, tergal color variability |
|
© Copyright source/photographer
· 1
Andrena erythrogaster, male genital armature, |
© Copyright source/photographer
· 1
Andrena erythrogaster, sternal plates 7 and 8, |
|
© Copyright source/photographer
· 1
Andrena erythrogaster, male, head lateral view |
Smithsonian Institution, Entomology Department · 1
Andrena erythrogaster, face |
|
Smithsonian Institution, Entomology Department · 1
Andrena erythrogaster, side |
Smithsonian Institution, Entomology Department · 1
Andrena erythrogaster, top |
|
Overview |
Reprinted with permission of the American Entomological Society from:
LaBerge, W. E., Bouseman, J. K. 1970. A revision of the bees of the genus Andrena of the Western Hemisphere. Part III. Tylandrena. Transactions of the American Entomological Society 96: 543-605.
Please report text errors to: leah at discoverlife dot org.
This beautiful bee is the most abundant Tylandrena in North America. It is marked in both sexes by the pale vestiture, the broad head and the abdomen usually being red at least in part. A few other Tylandrena have red integument and these are distinguished from erythrogaster by features listed in the diagnoses of the species in question.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 10-12 mm; width, 3-4 mm; wing length, M = 4.18 ± 0.254 mm; FL/FW, M = 0.91 ± 0.002; FOVL/FOVW, M = 3.59 ± 0.071.
INTEGUMENTAL COLOR. — Black except as follows: flagellar segments 1, 3 and 4 usually red at apices, segments 5-10 red below or segments 1-5 brown below; mandibles with apical halves rufescent; wing veins red to reddish-brown, membranes slightly to moderately infumate throughout; tarsi yellow to red; hind tibiae reddened at least apically; abdomen usually red at least in part, varies from black with rufescent apices to entirely red (rarely entirely black).
STRUCTURE. — Antennal scape length equal to first four and one-half flagellar segments or slightly more; flagellar segment 1 equals segments 2 plus 3 or slightly more, 2 distinctly shorter than 3 which is slightly shorter than 4. Eyes each about four times as long as broad, inner margins parallel. Malar space short, minimum length slightly more than one-sixth width. Mandible in repose extending well beyond middle of labrum. Galea moderately dulled by fine tessellation, short, broad, lateral portion about half as broad as dorsal. Maxillary palpus longer than galea, segmental ratio about 1.0:0.9:0.8:0.7:0.7:0.7. Labial palpus with segment 1 strongly curved along inner margin, ratio about 1.0:0.6:0.5:0.5. Labral process almost three times as broad as long, flat, slightly emarginate; without cristae, apex with transverse shallow depression or sulcus. Clypeus somewhat flattened medially, with median longitudinal impunctate line in apical half two or three punctures in width; punctures round, deep, separated mostly by half a puncture width or more, smaller posteriorly; surface shiny in apical half, tessellate posteriorly. Supraclypeal area dulled by minute, close-set punctures and tessellation. Genal area about one and one-half times as wide as eye in profile, with minute obscure punctures, with fine rugulae apically, surface dulled by fine reticular shagreening. Vertex above lateral ocellus equals one ocellar diameter or slightly less, dulled by dense tessellation and irregular, shallow punctures. Face above antennal fossae with coarse longitudinal rugulae diverging above, interrugal spaces dulled by fine shagreening and irregular, large, shallow punctures. Facial fovea extends down almost to mandible, separated from lateral ocellus by half to three-fourths an ocellar diameter.
Pronotum with well-marked humeral angle not forming ear-shaped lobe, dorsoventral ridge rounded below oblique suture which is deep and conspicuous. Mesoscutum with small, round, shallow punctures separated by one puncture width or more peripherally, by several puncture widths posteromedially, surface dulled by reticular shagreening. Metanotum opaque, with crowded round punctures and coarse tessellation. Propodeum with enclosure finely, densely tessellate, often slightly roughened along base; dorsolateral and posterior surfaces with shallow obscure punctures, dulled by fine tessellation; corbicular surfaces with sparse, distinct punctures, surface moderately shiny, coarsely tessellate. Mesepisternum with small round punctures separated by one to two puncture widths, surface dulled by fine irregular shagreening. Pterostigma slightly broader than from inner margin prestigma to wing margin; vein 1st m-cu meets second submarginal cell at or beyond middle of cell. Terga 1-4 with apical areas impunctate, slightly dulled by reticular shagreening; basal areas with minute obscure punctures mostly separated by three or four puncture widths or more (virtually impunctate except under high power magnification), surface moderately dulled by reticular shagreening. Pygidial plate V-shaped with rounded apex, without internal raised area, often with curved rows of small, posteriorly directed punctures. Sterna with apical areas impunctate, apical halves of basal areas with small crowded punctures, surfaces moderately shiny, finely shagreened.
VESTITURE. — Generally white or slightly cinereous; mesoscutal hairs sparse posteromedially; terga without trace of fasciae; sternal hairs long, forming weak subapical fimbriae; corbicula with long, curled, plumose hairs above and anteriorly, with long, simple, internal hairs; tibial scopal hairs moderately long, simple, white except brown just below basitibial plate; inner surfaces tarsi yellow.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 8.5-12.0 mm; width, 2.5-4.0 mm; wing length, M = 3.64 ± 0.188 mm; FL/FW, M = 0.88 ± 0.001; FS1/FS2, M = 1.68 ± 0.072.
INTEGUMENTAL COLOR. — Essentially as in female but wing membranes usually more hyaline and with more specimens with dark abdomens than among females.
STRUCTURE. — Antennae of moderate length, in repose not reaching back beyond posterior margins of tegulae; scape length about as long as first two and one-third flagellar segments; flagellar segment 2 distinctly shorter than 3 and broader than long, segments 3-10 longer than broad and subequal in length to each other. Eyes each about four times as long as broad, inner margins subparallel. Malar space, mandible and galea as in female. Maxillary palpus as in female but segmental ratio about 1.0:0.9:0.7:0.7 :0.5:0.6. Labial palpus as in female but ratio about 1.0:0.5:0.4:0.5. Labral process as in female but somewhat thickened apically. Clypeus as in female but punctures deeper and denser, without impunctate median line but small sparsely punctate median area sometimes present. Supraclypeal area, genal area and face as in female. Vertex above lateral ocellus usually equals about one and one-half ocellar diameters or slightly less, sculptured as in female. Thoracic sculpturing as in female but lateral surfaces of propodeum densely punctate in upper-posterior half or more. Wing venation as in female. Terga 1-5 as in female terga 1-4 but often slightly shinier. Sterna 2-5 as in female but punctures sparser and surfaces shinier. Sternum 6 with apex slightly emarginate medially, surface moderately dulled by sparse punctures and fine tessellation.
Terminalia as figured (Figs. 6-10); note the following: gonocoxite with median dorsal lobe short, apical lobe with sparse hairs; sternum 8 with short stout hairs medially, apical part not sharply separated from basal part.
VESTITURE. — Much as in female but lacking pollen-collecting hairs and often yellow, especially dorsally; clypeus with thick beard of long hairs completely hiding surface; sternal subapical fimbriae with sparse long hairs and usually narrowly interrupted medially.
GEOGRAPHICAL VARIATION. — Andrena erythrogaster exhibits considerable variation in integumental color, ranging from entirely black individuals to those in which the abdomen is entirely red. The dark individuals are most abundant in collections from the New England states and eastern Canada. The populations from the western states, particularly Nebraska and southward include the palest specimens. A rather even dine exists radiating out from the northeast. T. B. Mitchell (1960, p. 115) considered the dark form to be a separate subspecies which he called A. erythrogaster subaustralis Cockerell. Cockerell, however, named subaustralis from southern New Mexico, outside of the range of erythrogaster as now known and far from the concentration of dark populations in the northeast. A. subaustralis is a western species (close to erythrogaster) which is redescribed below.
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 10 mm.; clypeus evenly convex, projecting nearly one-half below suborbital line, finely, evenly and rather closely punctate beneath the short, white, dense pubescence, without a median impunctate line; facial foveae broad above, occupying fully two-thirds of area between eyes and lateral ocelli, covered with pale ochraceous tomentum; space between margin of vertex and lateral ocelli very slightly broader than their diameter; cheeks slightly broader than eyes, rounded posteriorly, rather dull, microscopically and obscurely punctate; malar space extremely short; basal segment of flagellum subequal to 2nd and 3rd combined; process of labrum broadly subtriangular, apex rather narrowly truncate: pubescence of entire body whitish, faintly ochraceous on thorax above;-thoracic integument rather dull, punctures of scutum shallow, rather fine, well separated anteriorly, becoming sparse posteriorly, quite sparse and fine on the more shining scutellum, very fine on pleura below, becoming somewhat more coarse and close above; enclosure of propodeum smooth but dull; propodeal corbicula rather short but well developed, tibial scope quite dense, the hairs short, simple, mostly whitish, but becoming fuscous toward extreme base, basitarsi somewhat narrower than their respective tibiae, the mid and hind pair pale ferruginous; 2nd submarginal cell slightly shorter than 3rd, receiving 1st recurrent near middle; abdominal terga ferruginous, somewhat shining, apical margins very slightly depressed, more yellowish, discs with extremely minute and obscure but rather close punctures, pubescence very short and obscure, entirely pale, but that of tergum 5 somewhat yellowish, fasciae not developed.
MALE. — Length 9 mm.; clypeus rather flat, projecting about one-third below suborbital line, very closely, finely and uniformly punctate beneath the dense pale pubescence; space between margin of vertex and lateral ocelli very slightly exceeding their diameter; cheeks very broad, rather flat, with a rounded, obscure, posterior angle opposite upper third of eye, surface dull, rather closely but very finely and obscurely punctate; malar space very short; basal segment of flagellum longer than 2nd, but shorter than 2nd and 3rd combined; process of labrum about twice as broad as long, slightly narrowed to the truncate and slightly emarginate apex; mandibles slender, somewhat curved, with a distinct inner subapical tooth, overlapping about one-third, without a basal inferior projection; pubescence of entire body pale, somewhat ochraceous on head and dorsum of thorax; thoracic integument rather dull and tessellate, punctures of scutum quite shallow, but fine and well separated anteriorly, becoming somewhat more sparse posteriorly, very fine and quite sparse on scutellum, quite close on pleura, fine below, slightly more coarse above; enclosure of propodeum dull and tessellate; all basitarsi slender and elongate, much narrower than their respective tibiae, mid and hind tarsi pale ferruginous; 2nd submarginal cell slightly shorter than 3rd, receiving 1st recurrent near middle; abdominal terga somewhat shining, apical margins somewhat depressed, yellowish-hyaline in contrast with the blackish, more basal portions of the discs, but these becoming yellowish-hyaline at extreme sides, discs with exceedingly minute and well separated, obscure punctures, pubescence short, suberect, entirely pale, fasciae not developed; apical portion of sternum 8 with a low submedian ventral projection, with short dense pubescence from here to the tip which is rather evenly rounded; penis valves moderately expanded basally, not excavated, gonocoxites hardly at all dilated apically, gonocoxal lobes rather broadly rounded, very slightly produced.
DISTRIBUTION. — Minnesota, Illinois and Ohio to Quebec and the New England states; April to July.
FLOWER RECORDS. — Robertson (1929) records this species on the following genera: Amelanchier, Antennaria, Claytonia, Crataegus, Heracleum, Prunus, Radicula, Rhamnus, Rhus, Salix and Viburnum.
|
|
|
Names | |
|
|
| Supported by | |
Updated: 2024-04-19 01:01:17 gmt
|
