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.
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Andrena bocensis is closely related to A. canadensis, but may be separated by its smaller size, the integument more shiny, and the clypeus more protuberant with fewer punctures. The two species are allopatric and, because of their close similarity, the possibility exists that A. bocensis is a subspecies of A. canadensis. However, I believe that A. bocensis is sufficiently distinct to warrant specific status.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 6.2-7.3 mm; width, 1.9-2.3 mm; wing length, M = 2.02 ± 0.054 mm; FL/FW, M = 1.02 ± 0.086; FOVL/FOVW, M = 3.55 ± 0.233.
INTEGUMENTAL COLOR. — Black except as follows: antenna yellow-brown beyond second flagellar segment; mandible red in more than apical half; tibial spurs white; distitarsi and basal half of tarsal claws yellow; apical half of tarsal claws red; tegula, wing veins and pterostigma light brown; wing membrane hyaline throughout except for very indefinite shading apically; metasomal terga and sterna with apical margin very narrowly hyaline; pygidial plate with apical third deep red, basal two-thirds yellow.
STRUCTURE. — Scape equal to flagellar segments 1 to 3, plus one-third of flagellar segment 4; flagellar segment 1 shorter than flagellar segments 2 plus 3. Eye 3.5 times longer than wide, with inner margin diverging above except upper end slightly incurved. Malar space 8 times wider than long. Mandible in repose extends for one-fourth its length beyond middle of labrum, with notch of mandible tooth equidistant between middle of labrum and mandible apex. Galea moderately tessellate, lateral surface slightly narrower than dorsal surface. Maxillary palpus projecting slightly beyond apex of galea, segmental ratio 0.6:0.7:0.6:0.5:0.4:0.5. Labial palpal basal segment compressed and curved laterally, apical segment attached subapically, segmental ratio 1.0:0.6:0.4:0.5. Labral process flat, twice as wide as long, median emargination broad, very shallow, depth one-tenth length of labral process. Clypeus moderately protuberant, projecting below eyes for slightly less than half its length, with large punctures separated by one-half puncture diameter except for median, longitudinal, impunctate area, narrow above, broadening below; upper margin shagreened, remaining area shiny. Supraclypeal area with small, widely spaced punctures obscured by moderate shagreening. Genal area 1.5 times wider than eye, with medium-sized punctures separated by less than 1 diameter near eye, more widely spaced toward posterior margin; third nearest eye shiny, remainder shagreened, dull. Vertex above lateral ocellus wider than 1 ocellar diameter, with deep, medium-sized punctures separated by less than 1 diameter, whole area with weak, irregular tessellation. Suprantennal area with longitudinal rugulae with small, indistinct, interrugal punctures. Facial fovea of equal width throughout, 3.5 times longer than wide, rounded above and below, reaching above to a line above median ocellus, below to a line below antennal fossa.
Pronotum with humeral angle and ridge well developed but humeral ridge broadly depressed medially where reached by weak, pronotal suture; shagreened throughout, dorsally with widely spaced, medium-sized, obscure punctures. Scutum with medium-sized to small punctures separated by 1 to 3 diameters; anterior third shagreened, dull, posterior two-thirds polished. Scutellum sculptured as for polished area of scutum. Metanotum with weak, irregular tessellation obscuring small punctures posteriorly and laterally. Propodeal enclosure with strong, irregular, longitudinal rugulae in anterior half, remaining area with moderate tessellation; dorsoposterior areas with margins near propodeal enclosure raised, with moderate tessellation and medium-sized punctures separated by 2 diameters; corbicular area with reticular shagreening, shiny, with widely spaced, sparse punctures in anterodorsal third. Mesepisternum with coarse, reticular shagreening dulling surface and medium-sized punctures separated by 2 to 3 diameters. Metepisternum with weak, reticular shagreening, and sparse, very small punctures dorsally, surface shiny. Mesobasitarsus broadly expanded medially, slightly less than 3 times longer than wide, slightly wider than metabasitarsus. Metabasitarsus widest basally, slightly more than 3.5 times longer than wide, width more than two-thirds width of metatibia. Metatibia widest apically, 4 times longer than wide. Wing with pterostigma slightly more than 4 times longer than wide, vein 1st m-cu meets second submarginal cell one-fifth of distance from apex.
Metasomal terga 1 to 5 with reticular shagreening except for apical, hyaline area smooth; disc and apical area of disc of tergum 1 impunctate; apical areas of discs of terga 2 to 4 with small punctures separated by 1 diameter, discs of terga 2 to 4 with very small, indistinct, scattered punctures; lateral areas of terga 1 to 4 with small, sparse punctures. Tergum 5 with large punctures separated by less than 1 diameter. Sterna 1 to 6 with weak shagreening; sternum 1 with medium-sized punctures separated by 2 to 3 diameters; apical margin with well developed, apical, median, V-shaped emargination. Sterna 2 to 6 with medium-sized punctures separated by 2 to 3 diameters except for small, median, basal, impunctate areas. Pygidial plate narrowed apically, moderately recurved, recurved area smooth, basal area with small, crowded punctures, edges lateral to punctured area raised.
VESTITURE. — White throughout. Clypeus with hairs sparse medially, more abundant laterally. Suprantennal area with upper half naked. Scutum with hairs very sparse on posterior two-thirds; scutellum naked except for sparse hairs on extreme lateral margins. Propodeal corbicula with scattered, long hairs in about anterodorsal third. Trochanteral floccus imperfect. Metasomal tergum 1 without an apical fascia, disc naked except for extreme anterior and lateral areas with medium length hairs; terga 2 to 4 with apical fasciae of recumbent hairs obscuring slightly more than one-fourth terga; discs naked except for very short, fine, sparse hairs and sparse, medium length hairs laterally. Tergum 5 completely obscured by long, appressed hairs. Sternum 1 with erect hairs throughout, apical fringe well developed; sterna 2 to 5 with subapical fimbriae and apical fringes well developed laterally but narrowly absent medially; sterna 2 to 6 with sparse, erect hairs throughout except on impunctate, basal, median, anterior areas.
MALE. MEASUREMENTS AND RATIOS. — N = 2;length, 5.6 mm; width, 1.7 mm; wing length, 1.8 and 1.7 mm; FL/FW, 0.95 and 0.96; FS1/FS2, 1.09 and 1.33.
INTEGUMENTAL COLOR. — Black except as follows: antenna beyond flagellar segment 1 yellow-brown beneath; mandible with apical half or less red; mesosoma as in female; metasomal terga and sterna broadly hyaline apically.
STRUCTURE. — Scape longer than flagellar segments 1 to 3; flagellar segment 1 slightly longer than flagellar segment 3; flagellar segment 2 slightly shorter than flagellar segment 3. Eye 3 times longer than wide with inner margin diverging above except for upper end slightly incurved. Malar space, mandible and galea as in female except mandible without ventrobasal lamella. Maxillary palpus with about half apical segment projecting beyond apex of galea, segmental ratio 0.5:0.6:0.4:0.5:0.6:0.6. Labial palpus as in female except palpal ratio 1.0:0.6:0.5:0.6. Labral process strongly reflexed, twice as wide as long, depth of apical emargination more than one-third length of labral process. Clypeus weakly protuberant; protruding below eyes for two-fifths its length, with large punctures throughout separated by less than one-half diameter except for small, median area where punctures weaker, more widely spaced, surface shiny. Supraclypeal area with irregular, crowded punctures. Genal area twice as wide as eye, produced to a blunt projection opposite midpoint of eye, sculptured as in female. Vertex and supra-antennal areas as in female except supra-antennal area with rugulae less prominent, punctures more prominent. Parocular area sculptured as for supraclypeal area.
Pronotum with humeral angle and ridge strongly developed except humeral ridge broadly and shallowly depressed medially; pronotal suture indistinct; area between pronotal lobe and humeral ridge with lower half smooth, shiny; remainder of pronotum shagreened, dorsally with medium-sized punctures separated by 1 diameter or more. Remainder of mesosoma as for female except propodeal corbicular area shagreened with large punctures separated by 2 to 3 diameters.
Metasomal terga 1 to 4 as in female except apex of disc with fewer punctures than female and tergum 1 punctured as for terga 2 to 4; tergum 5 similar to female except punctures slightly more widely spaced. Sterna 1 to 6 as in female except whole area with very weak, reticular shagreening, punctured throughout. Sternum 7 (fig. 73) with basal apodemes rounded basally, apex truncate, lateral areas with long hairs. Sternum 8 (fig. 74) with apex and neck region long, 1.5 times longer than basal region; apex and neck region long, 1.5 times longer than basal region; apex moderately expanded, neck with abundant, long hairs. Gonoforceps (figs. 70 to 72) in dorsal and lateral view with strong, longitudinal ridge. Penis valves in dorsal and ventral view with rounded, median expansion, apex bulbous; in lateral view as long as gonoforceps.
VESTITURE. — White throughout. Clypeus with abundant, long hairs throughout; polished areas of scutum and scutellum with sparse, short vestiture. Metasomal tergum 1 with sparse, erect hairs throughout, not forming a definite apical fascia; terga 2 to 4 with apical fasciae of nearly recumbent, short hairs, fasciae obscuring about one-fourth or more of terga; tergum 2 with long, sparse, erect hairs on median third, shorter, sparse, erect hairs laterally and on discs of terga 3 and 4. Tergum 5 with medium length, sparse hairs throughout, on sterna 1 to 5 forming thick, subapical fimbriae.
VARIATION. — This species varies little as is evidenced in the female by the low standard deviations for wing length and the ratio of FL/FW. The higher standard deviation for FOVL/FOVW is due to the difficulty of accurately measuring the facial foveae. The limits of the foveae are indistinct, especially dorsally.