Reprinted with permission of the University of Nebraska State Museum from:|
LaBerge, W. E. 1967. A revision of the bees of the genus Andrena of the Western Hemisphere. Part I. Callandrena (Hymenoptera: Andrenidae). Bulletin of the University of Nebraska State Museum 7: 1-316.
Please report text errors to: leah at discoverlife dot org.
This species is closely related to A. reflexa from which it can be distinguished by the sparse punctures over most of the body but especially on the metasomal terga. which are shiny and almost glabrous. It is placed, together with reflexa, near accepta because of the high vertex, broad genal areas, and yellow parocular maculae. A. calvata is known only from three males.
MALE. MEASUREMENTS AND RATIOS. — N = 3; length, 9-12 mm; width, 2.5-4.0 mm; wing length, M = 4.79 ± 3.175 mm; FL/FW, M = 0.93 ± 0.032; FS1/FS2, M = 2.57 ± 0.083.
INTEGUMENTAL COLOR. — Black except as follows: clypeus yellow except narrow apical margin and small maculae at tentorial pits; parocular areas yellow to level of antennal fossae; tegulae testaceous; wing membranes moderately infumate, especially apically. veins dark brown; terga and sterna with broad hyaline apical margins yellow to reddish, sterna often reddish medially in basal areas; distitarsi and basal half of tibiae yellow to reddish-yellow.
STRUCTURE. — Antenna of moderate length, surpasses tegulae; scape subequal to flagellar segments 1-3 in length; flagellar segment 1 equals segments 2 through 4, segments 2 and 3 subequal and each shorter than 4. Eyes about three and one half times as long as broad, converging slightly towards mandibles. Malar space as in accepta. Mandibles moderately decussate, in repose portion extending beyond middle of labrum equals one-third of mandible, bidentate. Galea opaque, dulled by regular tessellation; shape as in accepta. Maxillary palpus as in accepta but segmental ratio about 1.6:1.0:0.6:0.8:0.6:0.8. Labial palpus as in accepta but segmental ratio about 3.3:1.0:0.9:1.1. Labrum as in reflexa but process more distinct, rhomboidal in shape and weakly bidentate apically. Clypeus as in reflexa but with punctures absent or minute and sparse in medially one-fourth. Supraclypeal area as in reflexa but slightly sparser punctures. Genal area equals about one and one-half times eye in profile, punctures minute, separated mostly by 2 to 3 puncture widths, surface shiny, unshagreened. Vertex above lateral ocellus equals about 3 ocellar diameters, at apex punctate and reticularly shagreened, laterally with punctures small and sparse, surface shiny. Face above level of antennal fossae with longitudinal rugulae which do not reach ocelli, interrugal spaces punctate and area above rugulae punctate, medially surface moderately dulled by reticular shagreening, shiny laterally.
Pronotum as in accepta or reflexa but punctures almost obscured by tessellation. Mesoscutum, scutellum and metascutum with surfaces dulled by fine dense tessellation, punctate but punctures shallow, sparse and obscured by the tessellation. Propodeum with enclosure granulate to tessellate, outside of enclosure uniformly tessellate with sparse, shallow, obscured punctures separated by one to two puncture widths. Mesepisternum with extremely shallow, large, closely-spaced punctures which run into one another giving surface uneven appearance, surface reticularly shagreened, moderately dulled. Metepisternum smooth, impunctate below, reticularly shagreened, shinier than mesepisternum. Tibial spurs of hind legs moderately strongly curved in outer third or more.
Metasomal terga with minute, widely-spaced punctures separated mostly by three to four puncture widths or more, slightly less in apical areas; apical areas not impressed nor borders reflexed. Sterna with extremely few scattered punctures. Sternum 6 with broadly V-shaped,. shallow apical emargination, more punctate than basal sterna. Genital capsule and sterna 7 and 8 (Figs. 60-64) similar to those of reflexa but note the following: gonoforceps shorter, blunter; penis valve turned down and back at less than a right angle; sternum 7 deeply emarginate as in accepter, sternum 8 with small, shallow emarginate apex and narrow neck region.
VESTITURE. — Hair generally white to ochraceous (in holotype ochraceous). Distribution and type of hairs much as in accepta but terga almost glabrous, without apical pale fasciae, and sterna without distinct apical bands of long hairs.
TYPE MATERIAL. — The holotype male (CAS) and one male paratype (INHS) from 22 miles west of Springerville, Apache County, Arizona, were collected by P. D. Hurd, September 14, 1961, on Viguiera annua. One male paratype (GEB) from Willow Creek, New Mexico, was taken by R. M. and G. E. Bohart on September 3, 1933.