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 beautiful bee from California is very closely related to A. waldmerei. Indeed, if intermediates were to come to light from Kern and Los Angeles counties in California, waldmerei would be considered a southern subspecies of hurdi. The two sexes of hurdi can be distinguished from those of waldmerei primarily by color, hurdi having black vestiture on abdomen, legs, head and thoracic pleurae. In structure the two species are so much alike that a description of hurdi seems superfluous. The description of waldmerei, with few exceptions, can be applied to hurdi. Furthermore, Lanham's (1949, p. 33) description of hurdi is reasonably adequate.
FEMALE. MEASUREMENTS AND RATIOS. — N = 9; length, 13-14 mm; width, 3.5-4.0 mm; wing length, M = 5.19 ± 0.211 mm; FL/FW, M = 0.97 ± 0.017; FOVL/FOVW, M = 3.34-0.119.
INTEGUMENTAL COLOR. — Black except as follows: mandible rufescent at tip or in apical third to half; flagellar segments 3 or 4 to 10 dark brown below; wing veins and pterostigma dark brown, membranes moderately infumate; distitarsi slightly rufescent.
STRUCTURE. — As in waldmerei with the following exceptions: labral process slightly thickened apically; vertex above lateral ocellus equals slightly more than one ocellar diameter (about as 10:12 or 13); face above antennae with rugulae extremely fine and indistinct; propodeal dorsal enclosure with short, fine rugulae basally.
VESTITURE. — Head black except pale ochraceous around antennal bases. Thorax white to pale ochraceous above and on upper part of mesepisternum; black at sides and below; propodeal hairs pale ochraceous (including corbicula); corbicula without long plumose hairs anteriorly. Metasomal hairs entirely dark brown to black. Leg hairs dark brown or black but hind femora often with pale hairs anteriorly and inner surfaces hind basitarsi reddish-brown. MALE. MEASUREMENTS AND RATIOS. — N = 14; length, 10-13 mm; width, 2.5-3.5 mm; wing length, M = 4.52 ± 0.351 mm; FL/FW, M = 0.95-0.007; FS1/FS2, M = 1.89 ± 0.033.
INTEGUMENTAL COLOR. — Black except as follows: mandible with apical third to half rufescent; flagellar segments 2-11 dark brown below; wing veins and pterostigma dark brown to reddish-brown, membranes lightly infumate; terga 2 and 3 often with basal areas with transverse, median, slightly rufescent areas; distitarsi often rufescent at least apically.
STRUCTURE. — As in waldmerei with the following differences: vertex above lateral ocellus equals slightly more than one ocellar diameter; propodeal dorsal enclosure often without short rugulae basally; terga 2-4 with basal area punctures separated mostly by three to four puncture widths, surface shiny.
Terminalia as figured (Figs. 46-50); note the following: gonocoxite with apical process with abundant short hairs; sternum 7 as in subtilis but emargination even deeper; sternum 8 as in waldmerei but apex less rounded, truncate.
VESTITURE. — Head dark brown to black except clypeal hairs mostly white (dark at extreme sides); supraclypeal area, subantennal areas and face surrounding antennal bases usually with pale hairs; occiput behind vertex with some pale hairs. Thorax entirely white to pale ochraceous, slightly darker above than at sides. Tergum 1 with white hairs except in apical area; remainder of metasomal hairs black. Leg hairs black to dark brown except as follows: posterior surfaces fore and middle femora pale; hind femur with pale hairs or mixed pale and dark; inner surfaces hind basitarsi dark reddish-brown.