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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This medium-sized, western bee is closely related to andrenoides. The female differs from the dark females of andrenoides and from all other Parandrena by the more sharply pointed pygidial plate and the less densely punctate sterna 3 to 5. The male is very similar to that of andrenoides but differs in usually having the scutellum reticularly shagreened, a longer face (average), slightly more sparsely punctate sterna 2-5, and a smaller maculation on the parocular area.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 9-10 mm; width, 2.5-3.0 mm; wing length, M = 3.50 ± 0.166 mm; FL/FW, M = 0.98 ± 0.004; FOVL/FOVW, M = 3.46 ± 0.040.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical half or less rufescent; flagellar segments 3-10 reddish-brown below; tegula rufescent; wing membranes hyaline, yellowish, veins and stigma reddish-brown; tergal apical areas usually rufescent; sterna! apical areas hyaline, colorless; tibial spurs testaceous.
STRUCTURE. — Antennal scape length equals first four flagellar segments or slightly more; flagellar segments as in andrenoides. Eyes each almost four times as long as broad, inner margins converging slightly towards mandibles. Mandible and galea as in andrenoides. Labial palpus as in andrenoides but segmental ratio about as 1.0:0.7:0.5:0.7. Maxillary palpus as in andrenoides but ratio about as 1.0:1.0:0.8:0.8:0.7:0.7. Labral process small, triangular to rounded. Clypeus rounded from side to side, midline not protuberant as in concinnula and wellesleyana; punctures round, irregular in size, separated mostly by one puncture width laterally, sparser towards midline which is usually impunctate; surface dulled by reticular shagreening laterally and posteriorly. Supraclypeal area, face, facial fovea and vertex as in andrenoides. Genal area as in andrenoides but slightly narrower.
Pronotum as in andrenoides but dorsoventral ridge almost invisible below oblique suture and triangular area above suture with a few to several minute, longitudinal, irregular rugulae. Mesoscutum sparsely punctate, surface opaque, tessellate. Scutellum, mesepisternum and propodeum as in andrenoides but dorsal enclosure occasionally granular at base. Wing venation and tibial spurs as in andrenoides.
Metasomal terga 1-5 with extremely minute, sparse punctures (usually virtually impunctate) surfaces dulled by coarse reticular shagreening but apical areas usually moderately shiny. Pygidial plate V-shaped, narrow, apex relatively pointed, internal triangle as in andrenoides. Sterna 2-5 with basal areas with basal three-fifths impunctate or extremely sparsely punctate, apical two fifths or less with punctures separated mostly by one to two or more puncture widths; apical areas impunctate; surfaces dull to moderately dull, reticularly shagreened.
VESTITURE. — Generally white to pale ochraceous; form and distribution as in andrenoides.
MALE. MEASUREMENTS AND RATIOS. — N = 20; length, 7-11 mm; width, 1.5-2.5 mm; wing length, M = 3.21 ± 0.203 mm; FL/FW, M - 0.99 ± ;0.005; FS1/FS2, M = 1.94 ± 0.024.
INTEGUMENTAL COLOR. — As in andrenoides except as follows: mandible without basal yellow macula; parocular area yellow macula smaller, posterior margin extends from below tentorial pit in a sinuously or sharply indented line to eye margin at about level of prostomial suture (rarely reaching level of lower margins antennal fossae); wing veins reddish-brown.
STRUCTURE. — Antennae reaching middle of scutellum in repose; scape length equals almost first three flagellar segments; flagellar segments as in andrenoides. Eyes, mandible and galea as in andrenoides. Labial and maxillary palpi as in female. Labral process small, triangular or rounded, swollen at tip; labrum below process with shallow shiny transverse sulcus separated from process by minutely punctate zone. Clypeus rounded from side to side, with small round punctures separated by half to one puncture width laterally, sparse along midline, surface shiny except laterally and posteriorly where reticularly shagreened. Supraclypeal area, face, vertex and genal area as in andrenoides.
Pronotum with dorsoventral ridge poorly developed as in female, sculptured as in female. Mesoscutum as in female. Scutellum dull to moderately shiny, with at least delicate reticular shagreening. Mesepisternum and propodeum as in andrenoides but dorsal enclosure of propodeum often granular medially near base. Wing venation and tibial spurs as in andrenoides.
Metasomal terga 1-5 sculptured as in female terga 2-4. Sterna 2-5 with basal areas almost impunctate except in narrow zone of 2 or 3 rows of punctures just anterior to apical area. Sternum 6 with apicolateral tooth-like angles at right angles to surface but not twisted as in concinnula, apical emargination appears broadly bowl-shaped. Terminalia as figured (Figs. 67-68); note the following: Genital capsule as in bucculenta. Sternum 7 weakly emarginate apically, with abundant long hairs and a pair of dark spots near apex. Sternum 8 with apical part no broader than neck, truncate or slightly concave at apex.
VESTITURE. — Generally pale ochraceous to dark ochraceous with form and distribution as in andrenoides.