Reprinted with permission of the American Entomological Society from:
LaBerge, W. E. 1971b. A revision of the bees of the genus Andrena of the Western Hemisphere. Part IV. Scrapteropsis, Xiphandrena, and Rhaphandrena. Transactions of the American Entomological Society 97: 441-520.
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This is a small pale species from Texas and Oklahoma. The female can be distinguished readily from that of prima by not having red or orange terga, by the pale vestiture and by the shorter vertex and sparser thoracic punctation as described below. The male of dapsilis can be told from that of prima by the reflexed sixth sternum.
FEMALE. MEASUREMENTS AND RATIOS. — N = 6; length, 8-10 mm; width, 3.0-3.5 mm; wing length, M = 3.19 ± 0.313 mm; FL/FW, M = 0.92 ± 0.010; FOVL/FOVW, M = 2.91 ± 0.096.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical half or less rufescent: flagellar segments 3-10 brown below; wing membranes hyaline, colorless, veins dark reddish-brown; terga 2-5 with apical areas moderately translucent especially apically; distitarsi rufescent; tibial spurs testaceous.
STRUCTURE. — Antennal scape length equal to first four flagellar segments or slightly more: flagellar segments as in prima. Eyes each three and three-fourths as long as broad, inner margins parallel. Malar space as in prima. Mandible as in prima but short, in repose extending beyond middle of labrum by one-fourth its length or less. Galea as in prima. Maxillary palpus as in prima but segmental ratio about 0.9: 1.0: 0.7: 0.7: 0.6: 0.6. labial palpus as in prima but segmental ratio about 1.0: 0.6: 0.6: 0.6. l.abral process as in prima but not so broadly basally; labrum apical to process often with a single median weak crista, otherwise as in prima. Clypeus as in prima but median impunctate line broad. Supraclypeal areas ;»s in prima. Genal area in profile only slightly broader than eye, laterally with minute punctures separated mostly by one to two puncture widths (more crowded near eye margin) and fine reticular shagreening dulling surface, ventrally with abundant fine rugulae turned inwards towards hypostomal carinae. Vertex above lateral ocellus equals distinctly less than one ocellar diameter, surface dulled by minute punctures and fine tessellation. Face above antennal fossae with fine. crowded, longitudinal rugulae. Facial fovea as in prima but usually separated from lateral ocellus by less than one ocellar diameter.
Pronotum as in prima but space between ridge and posterior pronotal lobe with several complete longitudinal rugulae. Mesoscutum with small round punctures separated mostly by one to two puncture widths, surface shiny, lightly shagreened. Scutellum similar. Metanotum as in prima. Propodeum as in prima except dorsal enclosure with rugulae irregular and posterior surface with median sulcus narrow, at least four times as long as broad. Mesepisternum as in prima but punctures smaller.
Metasomal tergum 1 with apical and basal areas with punctures separated mostly by one-half to one puncture width, slightly sparser laterally in basal area. surface shiny. Terga 2-4 similar to 1 but basal area punctures more uniformly spaced and slightly more crowded. Pygidial plate as in prima. Sterna 2-5 with apical areas narrow, on sternum 2 less than one-fourth basal length medially: dulled by crowded punctures and fine reticular shagreening.
VESTITURE. — White except as follows: vertex of head and thoracic dorsum pale ochraceous: hind tibial plates and above brown; inner surfaces basitarsi pale yellow. Pollen-collecting hairs as in prima.
MALE. MEASUREMENTS AND RATIOS. — N = 17; length. 8-9 mm; width 2-3 mm; wing length, M = 3.13 ± 0.143 mm; FL/FW, M = 0.91 ± 0.005; FS1/FS2, M = 1.36 ± 0.022.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical third rufescent; flagellum with segments 2-11 dark brown below: wing membranes hyaline, colorless, veins dark reddish-brown: tergal apices slightly translucent: distitarsi rufescent: tibial spurs testaceous.
STRUCTURE. — Antennae short, in repose not reaching scutellum: scape length equals almost first three flagellar segments: flagellar segment 1 equals about one and one-third times second segment and slightly longer than third; segment 2 quadrate, segments 3-10 slightly longer than broad. Eyes and malar space as in prima. Mandible not decussate, in repose lip surpasses middle of labrum by one-third length of mandible or less. Galea as in female. Maxillary palpus as in female but segmental ratio about 0.6: 1.0: 0.6: 0.6: 0.5: 0.6. Labial palpus as in female. Labral process as in female but slightly larger, reflexed and more distinctly bidentate: labrum below process as in female but without median crista. Clypeus rather flat. with crowded punctures separated by half a puncture width or less. without impunctate median line. Supraclypeal areas as in female. Genal area in profile almost twice as broad as eye (about as 7: 4). rounded posteriorly, dulled by minute punctures and dense reticular shagreening. ventrally with fine longitudinal rugulae parallel to hypostomal carinae and reticular shagreening. Vertex and face above antennal fossae as in female.
Pronotum as in female. Mesoscutum and scutellum as in female but punctures more crowded. Metanotum, propodeum and mesepisterna as in female.
Metasomal terga 1-5 sculptured as in female terga 1-4 but punctures sparser, separated mostly by one to two or three puncture widths. Sterna 2-5 with narrow apical areas, basally with obscure punctures separated by one to two puncture widths or more, surface dulled by coarse tessellation. Sternum 6 reflexed across apical margin.
Terminalia as in figures 64-68: note (he following: sternum 7 deeply emarginate, hairy apically; sternum 8 similar to prima; genital capsule as in primes but dorsal lobe gonocoxite more acute apically.
VESTITURE. — Generally white to cinereous, slightly darker on vertex and thoracic dorsum; inner surfaces hind basitarsi white or extremely pale yellow. Terga without apical area fasciae; sterna 2-5 with apical fimbriae of short white plumose decumbent hairs: sternum 6 with tuft of short erect hairs basad of apical reflexion.
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