Text used courtesy of the Illinois Natural History Survey from:
Thorp, R. W., LaBerge, W. E., 2005. A revision of the bees of the genus Andrena of the Western Hemisphere. Part XV. Subgenus Hesperandrena. Illinois Natural History Survey Bulletin 37: 65-93.
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Andrena lativentris is a small species with pronotal humeral angles and lateral ridges in both sexes (although weak in the females) and black integument. The female can be recognized by the broad facial fovea separated from the lateral ocellus by about half an ocellar diameter or a little more and by the mesoscutal and scutellar hairs being mostly shorter than the width of the flagellum, although longer peripherally and especially in anterior fifth of the mesoscutum. The male of lativentris is marked by a yellow clypeal macula and sterna 2-5 with distinct subapical fimbriae of long, curled, relatively sparse, pale hairs.
FEMALE. MEASUREMENTS AND RATIOS. — N = 20; length, 8.0-9.5 mm; width, 2.03.0 mm; WL, 2.73 ± 0.095 mm; FL/FW, 0.90 ± 0.027; FOVL/FOVW, 2.78 ± 0.56.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical fourth rufescent; flagellum reddish brown below; wing membranes hyaline, not infumate, veins dark red or reddish brown; metasomal terga 1-A with apical areas broadly hyaline, colorless in apical fourth to third, reddened basally; tibial spurs pale yellow.
STRUCTURE. — Antennal scape as long as first four flagellar segments or slightly more; flagellar segments as in escondida. Eyes each four times as long as broad, inner margins parallel. Mandibles short, apposite, with subapical tooth. Malar space short, linear. Galea as in escondida. Maxillary palpus as in escondida but segmental ratio about as 0.8:1.0:0.7:0.5:0.5:0.6. Labial palpus with ratio about as 1.0:0.5:0.4:0.4. Clypeus short, sculptured as in escondida but punctures extremely obscure. Supraclypeal area and face above antenna! fossae sculptured as in escondida. Facial fovea extends below to just below a line at lower margins, antennal fossae two and one-fourth to two and one-third times ;is long as broad, separated from lateral ocellus by half an ocellar diameter or slightly more. Vertex above lateral ocelli short, equals about half an ocellar diameter or slightly more. Genal area in profile equals about one and one-third width of eye, surface dull, shagreened.
Pronotum without humeral angles and lateral ridges, surface dull, shagreened. Mesoscutum densely and finely tessellate, punctures minute, obscure, visible only at certain angles, separated by two or more puncture widths (slightly more crowded in anterior fifth and at extreme sides). Scutellum similar, not at all shiny. Propodeum declivous; dorsal enclosure tessellate, not at all punctatorugose: outside of enclosure with small sparse punctures; lateral carinae separated lateral from posterior surface complete. Pleurae dull, tessellate, punctures obscure, sculptured as in escondida.
Metasomal terga tessellate. dull. impunctate or punctures minute and obscure. Pygidial plate as in escondida. Sterna sculptured as in escondida.
VESTITURE. — White to pale ochraceous except as follows: facial fovea with tomentum silvery white to pale ochraceous, not brown in upper halves or more; metasomal terga 24 with white apical fasciae, that of tergum 2 narrowly interrupted medially; tergum 5 dark ochraceous medially. Pollen-collecting hairs as in escondida.
MALE: MEASUREMENTS AND RATIOS. — N = 15; length. 6.0-9.0 mm; width 2.0-3.0 mm; WL, M = 2.44 ± 0.224 mm; FL/FW, M = 0.94 ± 0.014; FS1/FS2, M = 1.92 ± 0.085.
INTEGUMENTAL COLOR. — As in female except as follows: clypeus with large pale yellow maculae, dark laterally and apically; metasomal terga 2-5 with apical areas with at least apical halves hyaline, colorless: distitarsi rufescent.
STRUCTURE. — Antennae short, female-like; flagellar segment 1 at least twice as long as segment 2, which equals segment 3, and broader than long; segments 4-7 about as long as broad; scape length as in female. Eyes three and one third times as long as broad, inner margins diverging towards vertex. Mandibles apposite, short, with subapical tooth. Galeae as in female. Maxillary palpus as in female but ratio about as 0.8:1.0:0.6:0.6:0.5:0.7. Labial palpus as in female but ratio about as 1.0:0.4:0.4:0.5. Labral process short, about twice as broad as long, emarginate, reflexed, shiny; labrum apical to process shorter than process. Clypeus dull. sculptured as in female. Supraclypeal area, face above antennal fossae and vertex as in female. Genal area as in female but only slightly broader than eye in profile.
Pronotum with weak humeral angles, lateral ridges present but weak, defined only above diagonal pronotal suture, dulled by fine shagreening. Thoracic sculpturing as in female but propodeum often finely punctatorugose at least basally; carina between lateral and posterior faces incomplete, short.
Metasomal terga sculptured as in female but surface slightly shiny, especially apical areas. Sternum 7 (Fig. 28) with lobes angulate laterally, apical emargination narrower. Sternum 8 (Fig. 29) with apical lobe entire, neck slightly broader than apical lobe, sternum thicker and broader than in pulverea.
VESTITURE. — White except inner surfaces of tarsi pale yellow. Metasomal terga 2-5 with relatively weak apical fasciae, broadly interrupted medially on tergum 2 and narrowly un tergum 3. Sterna 2-5 with distinct pale subapical fimbriae of long, sparse, curled, white hairs (as in escondida but longer and sparser).
TYPE MATERIAL. — The holotype female of lativentris (USNM No. 59,278) was collected from flowers of Baeria tenellis at Strathmore, Tulare Co., California, May 29,1937.
DISTRIBUTION. — Andrena lativentris has been collected in California (Fig. 2) from Colusa County south to San Diego County. It has been taken from March 9 through July 5, but chiefly from late March into May. A total of 24 females and 17 males were examined from localities listed below (including localities cited in the literature).
CALIFORNIA. COLUSA CO.: Bear Springs (S of Leesville). CONTRA COSTA CO.: Mt. Diablo; Russelman Park. KERN CO.: no locality. NAPA CU.: Butts Canyon (0.5 mi. S. of Napa Co. line). RIVERSIDE CO.: Elsinore; Hemet Lake, San Jacinto Mts.: Herkey Creek, San Jacinto Mts. SAN DIEGO CO.: Cuyamaca Lake. SOLANO CO.: Dixon (9 mi. S); Dozier (11 mi. S. of Dixon). TULARE CO.: Earlimart: Goshen (5.6 mi. N); Strathmore. YOLO CO.: Davis.
FLORAL RECORDS. — Andrena lativentris is probably an oligolege of Baeria sp., but little is known concerning its floral preferences as yet. It has been collected from flowers of the following plants (records from the literature are included).
Baeria sp., B. gracilis, B. tenella, Blennosperma nanum, Lasthenia chryostoma, Layia chrysanthemoides, L platyglossa.