Species account taken from: "A Revision of the Genus Ashmeadiella (Hymen., Megachilidae) Author(s): Charles D. Michener Source: American Midland Naturalist,Vol. 22, No. 1 (Jul., 1939), pp. 1-84"
This species has the aspect of inyoensis, to which it is closely related. It differs by the almost toothless hind tibial spurs of both sexes, by the bilobed, often reduced, median, marginal, clypeal projection of the female, and the finer punctation of both sexes.
Female: Inner margins of eyes parallel, their lower ends diverging below; face except clypeus and cheeks densely white hairy; under side of flagellum brown; clypeus rather coarsely punctate (more finely so than in inyoensis); apical margin of clypeus produced to a strong angle at each side, and to a slight, bilobed, median projection; labrum with apex narrowly notched, teeth on either side of notch broad, surface finely granular between punctures; mandibles reddish, base and teeth black; apical tooth of mandibles longer than others; cheeks narrower than eyes, seen from side; anterior ocellus much posterior to midpoint between antennal bases and posterior edge of vertex; distance between posterior ocelli greater than distance to nearest eye margin or to posterior edge of vertex; punctures of vertex fine and approximate; punc- tures of scutum slightly coarser than those of vertex, separated by a little smooth surface; scutum margined all around with white pubescence; mesepis- terna covered wtih white pubescence; scutellum and mesepisterna slightly more finely punctate than scutum; tarsi slightly rufescent; hind femora red; hind tibiae red except outer sides; hind tibial spurs with about three low, incon- spicuous teeth on each margin; wings clear. Abdomen red, considerably more finely punctate than scutellum; scopa white; tergites one to six with apical bands of white pubescence, fifth and sixth tergites pruinose. Length 4 1/2 mm. (varying to 5I/2 in some paratypes).
Male: Inner margins of eyes converginlg below except for lower parts which diverge; face covered with white pubescence; apex of clypeus with short concave space about two-thirds as long as base of clypeus; labrum rounded at apex; mandibles reddish, black basally and apically; flagellum reddish beneath; distance from anterior ocellus to bases of antennae nearly twice distance from anterior ocellus to posterior edge of vertex; distance between posterior ocelli greater than distance to eye or to posterior edge of vertex; vertex rather coarsely punctured, punctures separated by somewhat less than half their widths; cheeks about or slightly less than half width of eyes, seen from side. Scutum with punctures slightly smaller than those of vertex (coarser in another male specimen), separated by nearly half their diameters; mesepisterna more finely punctured than vertex; small segments of tarsi (or entire tarsi) somewhat rufescent; hind tibial spurs nearly entire. Punctures of first tergite fine and separated on dorsum by about one puncture width; punc- tures of following tergites coarser, separated by less than one puncture width; punctures of sides of teegites and of posterior tergites closer, not approximate and not as coarse as those of scutum; pubescent fasciae of tergites weak; first tergite red, second and third red except for transverse sub-basal black areas, that of third larger than that of second; fourth and fifth tergites with red on extreme sides and with broad apical margins red; teeth of sixth tergite largely median teeth fairly long and straight; median teeth broader than basal width, sides converging to rounded apex; concavity between median teeth broader than a semicircle. Length nearly 4 mm.
Holotype female (Calif. Acad. Sci., Ent. No. 4746) and three female paratypes: Cathedral City, Riverside County, California, on Larrea tridentata var. glutinosa, April 10, 1936 (C. D. Michener). One female paratype from two miles west of Edom, Riverside County, California, on same flower, March 26, 1936 (E. G. Linsley). Allotype male (Calif. Acad. Sci., Ent. No. 4747) and two female paratypes from Dos Palmos, Colorado Desert, California, March 19, 1934 (Cazier colelction) Two female and two male paratypes, La Quinta, California, March 4, 1936, and March 17 and May 2, 1934, on Hyptis emoryi and Larrea glutinosa (P. H. Timberlake); one female para- type, five miles east of Edom, California, April 10, 1937, on Larrea glutinosa (P. H. Timberlake). Additional specimens are from Arizona (no locality, Acad. Nat. Sci. Phila.) and Las Vegas, Nevada, April 15, 1930, on Dipetalia linifolia (D. E. Fox, U. S. N. M.).
Males vary considerably in the amount of black on the abdomen, some having an infuscated area on the first tergite, some having the first three tergites almost entirely red