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"
Ashmeadiella leucozona Cockerell, 1924, Proc. Calif. Acad. Sci., (4)12:556, ? 9; Michener, 1936, Am. Mus. Nov., 875:12, 15 (key).
This black, abundantly pubescent species can be easily recognized by the coarsely and sparsely punctate, shining scutum.
Male: Transfacial line considerably longer than facial line; face covered with white hair; under side of flagellum brown; inner orbits converging slightly below, except for lower thirds; apex of clypeus with a weak concavity very little shorter than basal width of clypeus; mandibles with broad red band subapically; punctures of vertex nearly approximate; anterior ocellus distinctly posterior to midpoint between antennal bases and posterior margin of vertex; distance between posterior ocelli distinctly greater than distance to nearest eye margin and a little greater than distance to posterior edge of vertex; cheeks about half as broad as eyes seen from side. Punctures of scutum coarse, separated by nearly their diameters, those of anterior part of scutum slightly finer than those of vertex, those of posterior part of scutum slightly coarser than those of vertex; scutum with band of white pubescence all the way around; tegulae testaceous; punctures of mesepisterna distinctly finer and a little closer than those of scutum; small segments of tarsi red. Punctures of abdomen quite close and strong, separated by less than their diameters, and somewhat finer than those of mesepisterna; teeth of sixth tergite reddish testa- ceous; lateral teeth of sixth tetgite acutely pointed; median teeth in the holo- type nearly twice as broad as long, and separated by a concavity which is longer than a semicircle, but in two other specimens (a cotype and the var. a) the median teeth are about as broad as long, and separated by a concavity which is broader than a semicircle; tergites one to five with distinct, broad apical-bands of pubescence, usually white but a little yellowish in a cotype. Length 5 to 6 mm.
Female: Eyes converging below; truncation of clypeus slightly concave, shorter than distance from end of truncation to lateral angle of clypeus; cheeks narrower than eyes, seen from side; transfacial line longer than facial; distance between posterior ocelli greater than distance to nearest eye margin, equal to distance to posterior edge of vertex. Length 7 mm.
Although there is considerable variation in the teeth of the sixth tergite of the male, there is probably only one species concerned. The holotype is the only known specimen with broad teeth. The var. a was distinguished by the narrower teeth, but, as stated above, the cotype has similar teeth.
Type: male; Guaymas, Sonora, Mexico, in California Academy of Sciences. Specimens from the Imperial Valley, California, appear to be this species but the males have narrower faces, and none of them have the broad median teeth of the sixth tergite of the holotype; females have more finely punctate abdomens than in Sonoran specimen