Extracted from: Timberlake P.H., (1962). A Revisional Study of the Bees of the Genus Perdita F. Smith, with Special Reference to the Fauna of the Pacific Coast (Hymenoptera, Apoidea) Part V. University of California Publications in Entomology Editors, Volume 28, No. 1, pp. 1-124.|
This species collects pollen from Mentzelia involucrata in the Colorado Desert of southern California and although it has the habitus of other species that visit Mentzelia the aedeagus and subgenital plate of the male exhibit some similarity to the same parts of members of the subfasciata subgroup. In this respect it may be considered a connecting link between the two subgroups.
Female.—Head and thorax dark green; labrum, clypeus, supraclypeal area, mesoscutum except anterior border, scutellum, and metanotum, black or blackish. Lateral face marks pale yellow, much higher than wide, acute above, and intruding between f oveae and margin of eyes. Clypeus entirely dark or with a median longitudinal yellow stripe (sometimes very faint or broad) join¬ing an arcuate yellow band on posterior margin of disk. Mandibles yellow at base and shading into red at apex. Collar of pronotum, more or less small cuneate marks on posterior corners of disk, and tubercles, yellow. Abdomen brownish fuscous with, an enclosed yellow band, more or less distinct but nubilous, on tergites 1 to 3 or 4; sometimes tergite 4 except for a darker apical band, and tergite 5, brownish yellow. Legs fuscous, front femora at apex and front tibiae on anterior side yellow. Antennae fuscous, flagellum brown beneath. Proboscis dark. Tegulae yellow at base and broadly hyaline on outer margin. Wings hyaline, nervures testaceous, subcosta and margins of stigma brown
Head as broad as long. Clypeus convex; disk somewhat broader than high, broadly rounded above, and with lateral extensions but slightly visible in frontal aspect of head. Facial foveae well impressed, about twice as broad as interval between them and margin of eyes and reaching from level of middle of antennal sockets about two-thirds of distance to level of anterior ocellus. Proboscis moderately long, included within fossa in repose; apex of galeae reaching base of stipites. Mandibles with small but distinct inner tooth and reaching far margin of proboscidial fossa. Pterostigma about four times as long as wide and somewhat narrower than first sub-marginal cell; part of marginal cell beneath stigma slightly longer than part beyond. Pygidial plate longer than wide at base, its sides rapidly converging to a narrow acute apical part some¬what convex on disk and curved downward. Frons, vertex, and notum of thorax minutely tessellate and moderately dullish; face below antennae and sides of thorax smoother and more shining; anterior half of frons and anterior border of mesoscutum with moderately close minute punc¬tures, becoming sparse on other parts of face and mesonotum. Pubescence whitish: rather thin, short, and erect on face and mesonotum; longer and moderately dense on cheeks and sternum; long and dense on front coxae. Length: 4.5-6 mm.; anterior wing, 3.4-3.6 mm.
Male.—Head and thorax dark green; disk of mesoscutum, scutellum, and metanotum, blackish. Mandibles except red tips, labrum, and most of face below level of antennae, yellow. Lateral marks in macrocephalous examples very broad to level of antennae and thence obliquely truncate to level of foveae; supraclypeal mark transverse or sometimes reduced to two dots; subantennal plates entirely dark, or yellow more or less margined with black. In rare specimens clypeus brownish, with a yellow T-mark on disk as in female. Cheeks usually broadly yellow on anterior third of orbits, but varying to a small yellow spot before base of eye, or entirely dark. Tubercles and collar of pronotum yellow; rarely a spot on each side of hind margin of disk. Abdomen brownish to brownish fuscous, without markings; venter brownish yellow. Legs blackish; apex of front femora, front tibiae and tarsi, and middle tibiae beneath, yellow; middle and hind tarsi brownish. Antennae fuscous, flagellum much browner than pedicel or scape and becoming brownish yellow beneath. Tegulae and wings as in female, except subcosta and margins of stigma darker brown.
Head sometimes small, rotund, but usually more or less enlarged; sometimes very large and quadrate, with very broad but rounded cheeks. Occiput broadly and moderately deeply concave. Disk of clypeus small in macrocephalous examples, not much broader than high; lateral exten¬sions narrow, as long as width of disk, and mostly visible in frontal aspect of head. Facial foveae punctiform. Mandibles broad at base, tapering to acute apex, and reaching far margin of pro-boscidial fossa. Flanks of pronotum at most only moderately impressed even in specimens with very large head. Inner tooth of tarsal claws about half as long as outer tooth. Sculpture and pubescence about as in female. Tergite 7 with a pygidiform medioapical lobe finely carinate on lateral margins; margins converging slightly toward moderately narrow truncate apex. Sub-genital plate about one and one-half times as long as wide; apex truncate and apical part of disk with fine, short pubescence. Dorsal lobes of caulis rather long and acute in both dorsal and lateral views, and with trace of fimbriation on inferior margin; superior pair of volsellae con¬cealed by dorsal lobes of caulis, inferior pair considerably longer and exposed; parameral lobes as long as caulis, moderately incurved, and subacute at apex; sagittae slenderly fusiform, the two rods slightly separated in apical part but converging to common obtuse apex. Length: 3.5-5 mm.; anterior wing, 2.8-3.2 TYITTI,