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 schunarzi, Cockerell (misidentification), 1924, Proc. Calif. Acad. Sci., (4)12:555; Michener, 1936, Am. Mus. Nov., 875:8.
This small, black, sparsely pubescent species is similar to prosopidis, schwarzi, and microsoma, but differs by the long median teeth of the sixth tergite of the male. Furthermore, in prosopidis at least, the teeth of the hind tibial spurs are considerably shorter than in sonora. The male differs from coloradensis and curriei by the long teeth of the sixth tergite, and from cactorum and dimalla by the position of the anterior ocellus, nearly twice as far from the antennal bases as from the posterior edge of vertex. The female differs from dimalla by the weakly emarginate clypeus and smaller size, and from that species as well as from cactorum and coloradensis by the narrow cheeks and the unusually extensive impunctate area of the posterior face of the propodeum.
Male: Transfacial line longer than facial; inner margins of eyes distinctly converging toward clypeus, except for lower ends; face largely covered with white pubescence; under side of flagellum brownish; clypeus finely and closely punctate, apical margin shiny with median emargination a little over half as wide as basal width of clypeus and demarked by distinct angles; mandibles reddish except basally; anterior ocellus far posterior to midpoint between antennal bases and posterior edge of vertex; distance between posterior ocelli somewhat greater than distance to nearest eye margin or to posterior margin of vertex; vertex and frons strongly punctate, punctures of frons approximate, those of vertex nearly so; cheeks about one-third as wide as eyes, seen from side. Scutum punctured like vertex; tegulae dark brown; scutum margined laterally with white hair, and with a pair of pubescent spots anteriorly; mesep- isterna more coarsely punctate than scutum, punctures slightly separated; wings clear; legs slightly brownish; inner margin of inner hind tibial spurs with about eleven teeth, outer margin with about eight; outer spurs with six or seven low oblique teeth on each margin. Abdomen rather strongly punc- tured, punctures rather close, not as coarse as those of scutum; posterior margins of tergites brownish, with bands of white pubescence; teeth of sixth tergite rufo-testaceous, lateral ones a little longer than wide and acutely pointed, median ones rather long, somewhat broadened basally, not twice as long as width at base, subparallel sided apically, apices rounded, ematgina- tion between them longer than a semicircle. Length less than 4 mm.
Female: Similar to male, differing thus: inner margins of eyes converging below; face not densely pubescent except laterally; clypeus as coarsely punctate as vertex except for broad, smooth, reddish, apical margin; truncation of clypeus hardly concave, slightly shorter than distance from its end to lateral angle of clypeus; angles marking ends of clypeal truncation somewhat ele- vated and rounded; mandibles with reddish, transverse, subapical band; dis- tance from first to third mandibular tooth but little more than half width of eye, and less than length of last three antennal segments; cheeks between one-third and one-half as wide as eyes, seen from side. Spots of pubescence at anterior end of scutum inconspicuous (or worn?); median posterior pit of propodeum not closely approached by punctured areas; teeth of outer side of inner hind tibial spur longer than in male; fifth tergite with apical pubescent band present only laterally; scopa whitish.
Holotype male (Calif. Acad. Sci., Ent. No. 4729) and allotype female (Calif. Acad. Sci., Ent. No. 4730) from Guaymas, Sonora, Mexico, April 8, 1921 (E. P. Van Duzee).
A male in poor condition from Shavers Well, Riverside County, California, April 8, 1934 (Bohart collection); a female from Morengo Valley, San Ber- nardino County, California, April 20 (T. D. A. Cockerell); a female from Box Canyon, April 12, 1934, on Olneya tesota (P. H. Timberlake); and two females from six miles south of Palm Springs, California, June 8, 1937, on Hugelia virgata (P. H. Timberlake) belong to this species. The fresh Cali- fornian examples have two large and sometimes confluent patches of white pubescence on the anterior edge of the scutum