Reprinted by permission of the Regents of the University of California from:
Donovan, B. J. 1977. A revision of North American bees of the subgenus Cnemidandrena (Hymenoptera: Andrenidae). University of California Publications in Entomology: 1-107.
Please report text errors to: leah at discoverlife dot org.
Andrena canadensis is very closely related to A. bocensis. Both species are without apical hair on metasomal tergum 1 and the wings of both are hyaline. Andrena canadensis is a little larger than A. bocensis, and its integument is a little less shiny. The two species are allopatric. Andrena canadensis is found in the eastern two-thirds of North America, and A bocensis is confined to the mountainous areas of the western tier of states within the United States. Andrena canadensis probably once ranged throughout North America, but became divided into two reproductively isolated populations during climatic changes in the Great Basin region. Andrena canadensis can be distinguished from A. bocensis by its larger size, the integument less shiny, and the clypeus with more dense vestiture with more punctures throughout. Andrena canadensis is related to A. nubecula through metasomal tergum 1 without apical vestiture, but the difference in wing coloration and integumental sculpture separates these species widely. It would seem to be more closely related to A. grindeliae which is larger and does have a weak, apical fascia on metasomal tergum 1, but which is similar in integumental sculpture.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 6.8-8.3 mm; width, 2.3-2.7 mm; wing length, M = 2.34 ± 0.072 mm; FL/FW, M = 1.00 ± 0.079; FOVL/FOVW, M = 2.92 ± 0.101.
INTEGUMENTAL COLOR. — Black except as follows: antenna light yellow ventrally beyond second flagellar segment; mandible with apical half red; tibial spurs nearly white, tinged lightly with yellow; apical half of tarsal claw red; tegula, wing veins brown, pterostigma dark brown except nearly hyaline medially; wing membrane with very light, apical shading, remainder hyaline; metasomal terga and sterna with apex moderately widely hyaline; pygidial plate very dark red-black.
STRUCTURE. — Scape equal to flagellar segments 1 to 3 plus nearly half of flagellar segment 4; flagellar segment 1 narrow in basal half, nearly equal to flagellar segments 2 plus 3; flagellar segment 2 very slightly shorter than flagellar segment 3. Eye 4 times longer than wide, inner margin diverging slightly above in about lower half, inner margin in about upper half broadly incurving. Malar space 7 times wider than long. Mandible in repose extends for a little more than one-fourth its length beyond middle of labrum, with notch of mandible tooth slightly less than one-half distance between middle of labrum and mandible apex from middle of labrum. Galea moderately tessellate, dorsal surface one-third wider than lateral surface. Maxillary palpus with apical segment projecting beyond apex of galea, segmental ratio 0.7:0.9:0.6:0.7:0.6:0.6. Labial palpus very strongly compressed laterally, moderately curved laterally, apical segment attached subapically, segmental ratio 1.2:0.6:0.5:0.6. Labral process trapezoid, twice as wide as long, apical emarginate area weakly reflexed, apical emargination shallow, depth one-fifth length of labral process. Clypeus weakly to moderately protuberant, extending below eyes for less than one-half its length, with large punctures separated by more than 1 diameter in small, lower, median area; punctures smaller, closer dorsally and laterally; upper half moderately shagreened, remainder shiny or nearly so. Supraclypeal area with close punctures obscured by moderate shagreening. Genal area 1.6 times as wide as eye, with small punctures separated by 2 to 3 diameters, more than posterior half shagreened, remainder shiny. Vertex above lateral ocellus slightly wider than 1 ocellar diameter, with medium-sized, deep punctures separated by 1 diameter, moderately shagreened. Supra-antennal area with well developed, longitudinal rugulae, with close, interrugal punctures. Facial fovea widest and rounded above, narrowed, more pointed below, 3 times longer than wide, deeply impressed, reaching above to a line above median ocellus, reaching below to a line above clypeus.
Pronotum with humeral angle and ridge very well developed, humeral ridge straight, complete, pronotal suture not obvious; pronotum dorsally with small, obscure punctures separated by 2 or more diameters, whole pronotum with moderate shagreening. Scutum with medium-sized punctures separated by 3 diameters except more widely spaced dorsally; anterior moderately shagreened, dorsal area shiny. Scutellum with narrow, posterior margin with shagreening obscuring punctures, remainder nearly impunctate, shiny. Metanotum with medium-sized, close punctures on posterior margin, moderately shagreened, Propodeal enclosure with irregular rugulae in anterior half; posterior half with broad, shallow, longitudinal, median depression, moderately tessellate; dorsoposterior area with medium-sized punctures separated by 2 to 3 diameters, moderately tessellate; lateral corbicular area with median-sized to large, widely and irregularly spaced punctures in anterodorsal third, weakly tessellate, nearly shiny. Mesepisternum with medium-sized punctures separated by 2 or more diameters, with reticular shagreening. Metepisternum with very small punctures in upper half, with very light shagreening, nearly shiny. Mesobasitarsus widest medially, more than 2.5 times longer than wide, somewhat wider than metabasitarsus. Metabasitarsus widest mesad of mid-point, less than 4 times longer than wide, two-thirds width of metatibia. Metatibia widest apically, slightly curved ventrally, nearly 3 times longer than wide. Tibial spurs normal. Wing with pterostigma 4 times longer than wide, vein 1st m-cu meets second submarginal cell slightly beyond middle.
Metasomal terga 1 to 4 with small punctures laterally on discs, tergum 1 with very few punctures apically on disc, terga 2 to 4 with punctures on apical margins of discs separated by 1 diameter, tergum 4 with scattered punctures on disc; remaining areas of terga 1 to 3 nearly impunctate, weakly tessellate. Tergum 5 with medium-sized punctures separated by 2 diameters, with weak tessellation. Pygidial plate narrowly rounded apically, broad, median and lateral areas raised, small apical area smooth, remainder with small, crowded punctures. Sternum 1 with small, median, V-shaped emargination, with small punctures separated by 3 diameters; sterna 2 to 6 with small punctures separated by 3 diameters except sterna 3 to 6 with median, basal, impunctate area. Sterna 1 to 6 weakly shagreened.
VESTITURE. — White throughout. Clypeus with sparse hairs. Scutum with very few, short, erect hairs. Scutellum naked except for some hairs on posterior margin. Propodeal corbicula with sparse, long, plumose hairs in about anterodorsal third. Trochanteral floccus imperfect. Metasomal tergum 1 with disc with hairs on lateral margins, apex of disc naked; terga 2 to 4 with apical fasciae of short, appressed hairs, fasciae obscuring one-third of terga; tergum 2 with disc naked; discs of terga 3 and 4 with very fine, very sparse, short hairs. Tergum 5 with long, posteriorly directed hairs on disc but basal half of disc not obscured. Sternum 1 with sparse, erect hairs, apical fringe moderately developed, subapical fimbriae moderately developed laterally, poorly developed medially; sterna 2 to 6 with erect hairs on punctured areas, hairs shortest anteriorly.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 5.8-7.0 mm; width, 1.5-2.1 mm; wing length, M = 2.04 ± 0.111 mm; FL/FW, M = 0.93 ± 0.083; FS1/FS2, M = 1.27 ± 0.139. INTEGUMENTAL COLOR. — Black except as follows: antenna red-yellow ventrally beyond first flagellar segment; mandible with more than apical third red; tegula, wing veins and pterostigma as in female; wing membrane hyaline throughout. Tibial spurs white or nearly so. Mediotarsi, basitarsi basal half of tarsal claws red-yellow; apical half of tarsal claws red.
Metasomal terga and sterna widely hyaline apically.
STRUCTURE. — Scape shorter than flagellar segments 1 to 3; flagellar segment 1 longer than flagellar segments 2 or 3; flagellar segment 2 shorter than flagellar segment 3. Eye 3 times longer than wide, with inner margin diverging moderately above except for upper end incurved. Malar space 10 times wider than long. Mandible in repose extending for one-fourth its length beyond middle of labrum, with notch of mandible tooth equidistant between middle of labrum and mandible apex. Galea as in female. Maxillary palpus with apical segment projecting beyond apex of galea, segmental ratio 0.6:0.7:0.5:0.5:0.5:0.6. Labial palpus as in female except segmental ratio 1.0:0.6:0.4:0.7. Labral process twice as wide as long, strongly reflexed, apical emargination depth one-third length of reflexed area. Clypeus weakly to moderately protuberant, somewhat depressed medially, extending below eyes for more than one-third its length, with large punctures, separated in lower, median area by 1 or more diameters, more closely spaced above and laterally; shiny. Supraclypeal area with close, irregular, medium-sized punctures, shiny. Genal area twice width of eye, strongly produced to a prominent angle opposite midpoint of eye, with a weak ridge running dorsally from the angle to below vertex, with medium-sized punctures separated by 1 or more diameters, more than posterior half shagreened, remainder near eye shiny. Vertex as in female except tessellation weak. Supra-antennal area with longitudinal rugulae, rugulae becoming weak, irregular near ocellus with obscure, interrugal punctures. Parocular area with irregular, close punctures obscured by light shagreening, shiny.
Pronotum with humeral angle and ridge strongly developed, ridge straight, almost carinate, not or scarcely depressed medially, pronotal suture not visible, sculpturing as in female except broad angle between humeral ridge and pronotal lobe smooth or nearly so, shiny. Remainder of mesosoma sculptured as in female except as follows: scutum with posterior two-thirds of dorsal area shiny, lateral areas of propodeum with medium-sized punctures in upper third, separated by 2 diameters.
Metasomal terga 1 to 5 with discs with small punctures separated by 3 to 4 diameters except separated by 1 diameter on apical areas of discs of terga 2 to 4, with light, reticular shagreening, nearly shiny. Sternum 1 as in female, sterna 2 to 6 with small punctures separated by 2 diameters, with light, reticular shagreening, nearly shiny. Sternum 7 (fig. 68) with apex broadly and irregularly truncate, with hairs on truncate area; basal apodemes narrowing and rounded apically. Sternum 8 (fig. 69) with apex and neck region longer than basal region, apex broadly expanded, neck with abundant, long hairs. Gonoforceps (figs. 65 to 67) in dorsal view with inner apical edge somewhat emarginate; oblique ridge not reaching outer edge. Penis valves in dorsal and ventral view widest medially, lateral expansion rounded, narrowing to lobe-like apex, in lateral view downcurved, shorter than gonoforceps.
VESTITURE. — White throughout. Clypeus with abundant, long hairs. Scutum with sparse, erect hairs. Scutellum with sparse hairs mostly from posterior margin. Metasomal tergum 1 with sparse, long, erect hairs on apical area of disc, long hairs on lateral margins of disc. Terga 2 to 4 with apical fasciae of short, sub-appressed hairs, fasciae present on one-third or slightly more of terga, not obscuring surface, terga 1 to 5 with sparse, erect hairs on discs, longest on tergum 1, shorter on more posterior terga. Sternum 1 with sparse, erect hairs, apical fringe well developed; sterna 2 to 5 with apical fringes strongly developed, remainder of sternal areas with sparse, erect hairs.
VARIATION. — A small number of females have a very few, sparse hairs apically on metasomal tergum 1. Eight females from West Point, Cuming Co., Nebraska, 1 female from Pleasant Lake, Benson Co., North Dakota, show this character; however the female from Pleasant Lake is stylopized, but the occurrence of 3 other females from North Dakota with this character suggests that the Stylops is not necessarily responsible for the development of the hair on tergum 1. One female from Willow Creek, New Mexico, has 2 submarginal cells in the right wing.
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 slightly convex, projecting but little below suborbital line, smooth, rather closely and finely punctured, punctures quite close toward sides, rather sparse medially; facial foveae narrow, occupying above but little more than half of space between eyes and lateral ocelli, covered with yellowish-white tomentum; space between margin of vertex and lateral ocelli about equal to their diameter; cheeks slightly broader than eyes, smooth and shining, very minutely and rather closely punctate; malar space extremely short; basal segment of flagellum subequal to 2nd and 3rd combined; process of labrum large, nearly as long as broad, subquadrate, apex slightly emarginate; mandibles of moderate length, with a small, subapical, inner tooth; pubescence of head, thorax and legs entirely pale ochraceous, erect and rather long and dense except on scutum and scutellum medially; scutum anteriorly, pleura and propodeum dull and tessellate, scutellum and remainder of scutum polished. scutum anteriorly with scattered, rather distinct, shallow punctures; enclosure of propodeum smooth; propodeal corbicula well developed, with a distinct anterior fringe; trochanteral floccus well developed; tibial scopa quite dense, hairs very minutely and obscurely plumose; fore and hind basitarsi somewhat narrower than their respective tibiae, mid basitarsi fully as broad as their tibiae; 2nd submarginal cell shorter than 3rd, receiving 1st.recurrent just beyond middle; abdominal terga dull, tessellate, impunctate, apical margins very narrowly and slightly depressed, becoming hyaline along rims, discal pubescence extremely short and obscure, entirely pale, terga 2-4 with dense, whitish, apical fasciae.
MALE. — Length 8 mm.; clypeus much broader than long, quite flat, finely and densely punctate beneath long, dense pubescence; space between margin of vertex and lateral ocelli very slightly greater than their diameter; cheeks broad and flat, with a small, acute angle opposite middle of eye, margin above this angle subcarinate, surface somewhat shining, very minutely punctate; malar space extremely short; basal segment of flagellum considerably shorter than 2nd and 3rd combined; process of labrum very short, about twice as broad as long, the truncate apex very slightly emarginate; mandibles slender, slightly flexed, overlapping about one-third, with a fine but distinct, inner, subapical tooth; pubescence of head, thorax, legs and base of abdomen entirely pale ochraceous, rather long, erect and thin, exposing surface except on clypeus; scutum anteriorly, pleura and propodeum dull and tessellate, scutum posteriorly and scutellum polished, punctures shallow and rather sparse but distinct on pleura and scutum anteriorly, becoming finer and more sparse posteriorly and on scutellum; enclosure of propodeum dull and relatively smooth; all basitarsi slender and elongate, narrower than their respective tibiae; 2nd submarginal cell much shorter than 3rd, receiving 1st recurrent just beyond middle; abdominal terga rather dull, with exceedingly minute and obscure, scattered punctures, apical margins very narrowly and slightly depressed, with rather thin, whitish, apical fasciae, discal pubescence short, suberect and entirely pale; apical portion of sternum 8 slender and elongate, sides nearly parallel, with a very slight, median, ventral protuberance, apex beyond subapical dorsal ridge about as long as broad, somewhat rounded; penis valves slender basally, gonocoxites only slightly dilated apically, gonocoxal lobes somewhat rounded, very slightly produced.
DISTRIBUTION. — Minnesota to Michigan, New York, New Jersey, the New England states and Nova Scotia; August and September.
FLOWER RECORDS. — Aster and Solidago. Recorded by Brittain and Newton (1934) also on Epilobium.
|
