Extracted from: Timberlake P. H., (1975). The North American Species of Heterosarus Robertson (Hymenoptera, Apoidea). Universiry of California Press Berkeley. Los Angeles• London. ISBN: 0-520-09528-6.|
This is a small Mexican species most closely allied to arizonicus, but considerably duller. The male has the clypeus, lateral marks, tubercles, all tarsi, and tibiae in part yellow.
Male. - Black; mandibles except reddish tips, labrum, clypeus, lateral marks reaching somewhat higher than summit of clypeus, tubercles, all knees, base, and apex of all tibiae (and anterior side of front pair) and all tarsi yellow. Antennae dark, flagellum brown beneath. Tegulae testaceous. Wings moderately dusky hyaline, nervures and stigma brownish fuscous.
Head rotund, slightly broader than long, and moderately thick fronto-occipitally; inner orbits strongly convergent below. Cheeks about half as wide as eyes and widest opposite beginning of upper fourth of eyes. Occiput broadly and rather strongly concave, with rounded, ill-defined margins. Posterior ocelli slightly more than their diameter apart, about twice their diameter from occipital margin, and three times their diameter from nearest eye. Facial foveae small, slender, diverging from margin of eyes above. Antennae inserted near middle of face, scape almost reaching level of anterior ocellus; joints 2 and 3 of flagellum about as thick as long, together slightly longer than joint 1; middle joints of flagellum a little longer than thick. Antennal sockets about equidistant from each other and nearest eye. Face below level of antennae gently convex; subantennal plates obsolete; disk of clypeus about as broad as high, sides converging almost straight to moderately wide truncate summit. Mandibles acute, reaching far margin of labrum. Proboscis short, galeae shorter than stipites and exceeded by palpi; first joint of labial palpi nearly as long as next three together. Second submarginal cell narrowed slightly less than one-half above, and receiving first recurrent nervure about one-fourth of its length from base. Head and thorax dull, minutely and densely punctured, but face below level of antennae less dull, with punctures mostly a puncture-width or more apart. Mesopleura minutely rugulose and obscurely punctured. Propodeum minutely rugulose, basal area very narrow and finely wrinkled. Pubescence of head and thorax extremely short, but becoming somewhat longer and more evident on cheeks, sternum, metanotum, and sides of propodeum; collar of pronotum thinly banded with tomentum. Abdomen dull, minutely, rugulosely tessellate and impunctate, with apical depression of tergites smooth and more shining; basal impression of tergite 2 and of following segments poorly defined but lineolate and duller than disk; apical depressions narrow, covering not more than one-third of segments. Abdomen thinly and finely pubescent, with longer hairs on lateral margins and long hairs overlying apical depression of tergites 4 to 6. Hair of venter short, whitish, appressed, directed obliquely inward from each side on sternites 2 to 5, and less dense on more basal segments. Sternite 6 bare, shining and with small median emargination. Subgenital plate about three times longer than wide, with strong ridges beneath close to lateral margin, and with short dense pubescence at apex. Parameral lobes of genital armature strongly deflexed, obliquely narrowed from just beyond middle to acute apex, and fringed on outer margin with about seven long plumose hairs; sagittae slender, nearly as long as parameral lobes. Length, 3.5 mm; anterior wing, 2.9 mm; width of abdomen, 0.7 mm.
Female. - Black, with tubercles, antennae, and legs dark. Tibial spurs pale testaceous; small spot at base of front and middle tibiae pale yellow. Mandibles reddened except at base. Pygidial plate red. Tegulae testaceous brown. Wings dusky hyaline, nervures and stigma brownish fuscous.
Head distinctly broader than long; inner orbits rather strongly converging below. Cheeks about half as wide as eyes. Posterior ocelli somewhat closer to ill-defined occipital margin than their dis-tance apart, and nearly twice that distance from nearest eye. Facial foveae narrow, well impressed, a little longer than space between posterior ocelli. Antennae inserted near middle of face and reaching nearly to base of wings; middle joints of flagellum as long as thick. Face strongly convex from occipital to oral margin although comparatively little from side to side. Subantennal plates very obscurely indicated; disk of clypeus much broader than high. Process of labrum smooth, shining, nearly twice as broad as long, and rounded at apex. Mandibles simple, subacute, not reaching far margin of labrum. Proboscis short, galeae much shorter than stipites. Second submarginal cell narrowed one-half above and receiving first recurrent nervure about one-third of its length from base. Head and thorax dull, very minutely tessellate and minutely punctured. Punctures of face below level of antennae mostly a puncture-width apart, becoming closer on frons, and coarser on clypeus and well separated on anterior middle of disk; punctures of mesonotum slightly finer than those of face, becoming slightly separated on each side of disk on outer side of parapsidal lines. Mesopleura opaque, obscurely punctured. Pro-podeum minutely rugulose, basal area narrow, with rather obscure longitudinal wrinkles. Abdomen narrowly ovate, somewhat more than twice as long as wide, lineolate, very minutely punctured and dull, but basal declivity of tergite 1 smooth and shining. Apical depression of tergites broad and minutely tessellate; base of tergites 2 to 4 not definitely impressed but rather broadly impunctate. Pygidial plate about as long as wide at base and rather narrowly rounded at apex; disk plane. Pubescence in general similar to that of male; apical fimbria, thin, short, and ochreous. Scopal hair of hind legs strongly curved and about as long as greatest width of tibia. Length, 4.5 mm; anterior wing, 3.7 mm; width of abdomen, 1.4 mm.