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.
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This large red-abdomened species is very similar in color to pale specimens of A. erythrogaster from which it can be distinguished in either sex by the form of the pronotum as described below. A. jessicae is more closely related to A. wilmattae than to any other Tylandrena but can be readily separated from wilmattae by the less densely punctate terga and the red coloration.
FEMALE. MEASUREMENTS AND RATIOS. — N = 16; length, 12-14 mm; width, 3-4 mm; wing length, M = 4.81 ± 0.217 mm; FL/FW, M = 0.92 ± 0.005; FOVL/FOVW, M(14) = 2.96 ± 0.233.
INTEGUMENTAL COLOR. — Black except as follows: mandible mostly red; labrum usually entirely red; clypeus usually red apically and occasionally along midline; scape red at least near base and on upper surface, first flagellar segment red, segments 2-10 dark brown below; tegulae testaceous, orange; wing veins yellow to red except dark subcosta, membranes moderately infumate, yellow, darker apically; terga red except base of tergum 1 and small lateral maculae on tergum 2; sterna red; legs red except coxae, trochanters and occasionally bases of femora.
STRUCTURE. — Antennal scape length equals first three and one-half flagellar segments; flagellar segment 1 slightly longer than segments 2 plus 3, segment 2 about as long as 3 and slightly shorter than 4, segments 2 and 3 quadrate, 4-10 slightly longer than broad. Eyes each almost four times as long as broad, inner margins slightly diverging towards mandibles. Malar space and galea as in perplexa. Maxillary palpus as in perplexa but segmental ratio about 0.8: 1.0: 0.8 :0.7:0.6:0.7. Labial palpus as in perplexa but ratio about 1.0:0.6:0.5:0.5. Labral process two to two and one-half times as broad at base as long, entire or slightly emarginate medially; labrum below process without crista, flat, moderately dull, with a few obscure longitudinal rugulae. Clypeus rounded, with a narrow but distinct, complete, median, longitudinal, impunctate line; punctures large, round, crowded; surface moderately shiny, coarsely shagreened. Supraclypeal area with coarse punctures almost as large as those on adjacent area of clypeus, surface moderately dulled by shagreening. Genal area slightly more than one and one-half times as broad as eye in profile, with minute punctures and fine shagreening moderately dulling surface. Vertex above lateral ocellus equals one and one-third to one and one-half ocellar diameters, opaque, finely tessellate and closely punctate above ocelli. Face above antennae with extremely fine longitudinal rugulae and abundant punctures moderately dulling surface. Facial fovea broad, separated from lateral ocellus by half an ocellar diameter or slightly more.
Pronotum as in wilmattae. Mesoscutum with small round punctures crowded anteriorly and peripherally, posteromedially separated by three to four puncture widths except along midline, surface dulled by fine tessellation (often somewhat shiny posteromedially). Scutellum similar but shinier. Metanotum and propodeum as in erythrogaster but propodeum with dorsal and posterior area punctures denser and dorsal enclosure finely granular throughout. Mesepisterna as in perplexa. Wing venation as in perplexa but second submarginal cell along anterior margin about as long as third cell. Terga 1-4 with apical areas with punctures minute, separated mostly by two puncture widths; tergum 1 with basal area impunctate or almost so; terga 2-4 with basal area punctures minute, separated mostly by two to three puncture widths; surfaces shiny, with delicate reticular shagreening. Pygidial plate V-shaped with small rounded apex, without raised internal triangle. Sterna 2-5 as in erythrogaster but duller, shagreening rather coarse and dense.
VESTITURE. — Entirely pale ochraceous to yellow, slightly brighter or darker on thoracic dorsum and vertex of head. Terga 2 and 3 with weak apical fasciae of yellowish pubescence broadly interrupted medially; tergum 3 with complete pale apical fascia but thinned medially. Propodeal corbicula with long plumose hairs anteriorly as well as dorsally. Inner surface tarsi golden-yellow.
MALE. MEASUREMENTS AND RATIOS. — N = 5; length, 11-12 mm; width, 2.5-3.0 mm; wing length, M = 4.30 ± 0.594 mm; FL/FW, M = 0.91 ± 0.008; FS1/FS2, M = 1.48 ± 0.012. INTEGUMENTAL COLOR. — Black except as follows: mandible with at least median half rufescent; flagellar segments 2-11 brown or reddish-brown below; tegulae testaceous, orange; wing veins red, membranes slightly infumate, yellow; terga red except base of tergum 1 and terga 5- or 6-7 brown basally and hyaline apically; sterna red; legs red except dark coxae, trochanters and femora (femora may be reddened apically).
STRUCTURE. — Antennae and eyes as in perplexa. Malar space and mandible as in female. Maxillary palpus as in female. Labial palpus as in female but segmental ratio about 1.0:0.5:0.3:0.4. Labral process about twice as broad at base as long or slightly broader, thickened apically, entire or extremely weakly emarginate medially. Clypeus as in female but slightly flatter and without median impunctate line or this line weak and incomplete. Supraclypeal area, genal area, vertex and face above antennae as in female.
Pronotum as in female but humeral angle less ear-shaped, more prominent and triangular in lateral view. Thoracic sculpturing as in female except as follows: surfaces mesoscutum and scutellum usually shinier; lateral surface propodeum similar to posterior surface. Wing venation as in female. Terga sculptured as in female but tergum 5 similar to terga 2-4. Sterna 2-5 sculptured as in female but punctures sparser; sternum 6 without median sulcus, apex weakly emarginate.
Terminalia as figured (Figs. 31-35); note the following: gonocoxite with apical process elongate, hairy; sternum 7 with large V-shaped median emargination; sternum 8 similar to that of perplexa.
VESTITURE. — As in female but without pollen-collecting hairs; sterna 2-5 with weak subapical fimbriae of long, sparse hairs.