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.|
Although P. bicuspidariae is undoubtedly allied to other species found on Mentzelia, certain of its characters are quite different, particularly the facial foveae of the female, the broad bidentate apex of the apical tergite, and the genitalia of the male. It collects pollen from Mentzelia involucrata in the deserts of southern California.
Female.—Head and thorax dark green, becoming bluish on propodeum and black on supra-clypeal area, subantennal plates, mesoscutum except antenior border, scutellum, and metanotum. Mandibles except red tips, labrum, clypeus, and lateral marks, white; suffused supraclypeal mark rarely present. Collar of pronotum, interrupted band on hind margin of disk, and tubercles, white. Sometimes a small white spot on flanks of propodeum just above hind coxae; rarely almost whole posterior half of propodeum white, including entire flanks, two spots on metapleura, and a small spot on anterior middle of mesopleura; in one specimen also a small white spot onscutellum. Abdomen pale yellowish white, marked above with pale fuscous or brown coloration; basal declivity of tergite 1 more or less entirely dark, with color deepening on apical corners of declivity; dark band on apical margin of tergites 1 to 4 or 5, supplemented by dark spot on basal corners, markings becoming progressively fainter toward apex of abdomen. White area on tergite 1 sometimes reduced to narrow subapical band, or sometimes covering most of basal declivity; white band on tergite 2 sometimes enclosed. Legs yellowish white; posterior side of front and middle femora and tibiae except at knees, dorsal side of hind femora and hind tibiae, and tarsi, pale fuscous or brown, with dark markings sometimes faint except on hind tibiae and tarsi. Antennae fuscous, scape white beneath, flagellum dull yellowish beneath. Tegulae white at base, broadly subhyaline on outer margin. Wings whitish hyaline, nervures pale testaceous, subcosta more or less pale ferruginous, margins of stigma faintly brownish.
Form rather slender; head nearly as broad as long. Disk of clypeus convex, somewhat broader than high, broadly rounded above, truncate anteriorly. Mandibles stout, curved, with well-developed inner tooth, and reaching slightly beyond far margin of proboscidial fossa. Proboscis of moderate length, apex of galeae not quite reaching base of stipites when folded in repose. Facial f oveae deeply impressed, generally more than twice as wide as space between them and margin of eyes, and reaching from level slightly above middle of antennal sockets nearly two-thirds of distance to level of anterior ocellus. Pterostigma as long and nearly as broad as first submarginal cell; part of marginal cell beneath it distinctly longer than part beyond, latter being as long as wide. Inner tooth of tarsal claws about half as long as outer tooth. Pygidial plate plane; sides converging to narrow, subtruncate, or slightly emarginate apex. Head and thorax finely tessellate and moderately shining, face below antennae smooth and more shining; punctures on middle of face and on anterior part of mesoscutum extremely fine and sparse. Pubescence white, very sparse and short on middle of face, vertex, and anterior part of mesoscutum; longer on underside of head and on mesopleura; long and dense on front coxae and mesopectus. Length: about 3.5-4 mm.; anterior wing, 2.7-3 mm.
Male,—Head, thorax, and abdomen yellow, with dark markings very variable in extent. In palest specimens an abbreviated greenish band just enclosing ocelli; mark on occiput and two narrow vittae on mesoscutum, brownish; Y-shaped mark on propodeum and large circular mark on each side of mesopectus, black; basal declivity of tergite 1, and band at apex of tergites (becoming successively fainter toward apex of abdomen), brown. Dark marks of thorax sometimes greenish, with vittae of mesoscutum widened anteriorly; sometimes propodeum almost all yellow; sometimes mark at base of tergite 1 irregularly trifid and remainder of abdomen only faintly marked. In darkest specimens, occiput and vertex dark greenish, with dark color descending halfway between level of foveae and anterior ocellus, but with cheeks remaining yellow to summit of eyes. Thorax above dark green, except pronotum, lateral margins of mesoscutum, a transverse mark on posterior middle of mesoscutum, and mark on scutellum. Sides of thorax and flanks of propodeum yellow, except for a blackish oblique band from beneath tegulae to middle coxae. Dark markings at base of abdomen more or less extensive, tergite 1 sometimes entirely dark and the yellow on tergite 2 reduced to a narrow, nubilous basal band, but dark markings on apical segments narrow and faint. Yellow mark on posterior middle of mesoscutum sometimes much enlarged, so that disk has two dark vittae broadly confluent in front. Type male an intermediate example with rather broad dark band across vertex, narrowed where it touches eyes, vittae on mesoscutum widened anteriorly, with a dark cloud between their anterior ends, and dark Y-mark on propodeum obsolescent. Legs entirely yellow, or hind tibiae and tarsi faintly brownish. Antennae yellow, flagellum brownish above and dull yellowish beneath, pedicel dark brown or fuscous above. Mandibles except red tips, and proboscis, yellow. Tegulae and wings as in female, except spot at base of tegulae yellow instead of white.
Head about normal size to moderately enlarged, becoming quadrate in the more macrocephalous specimens, with cheeks broader than eyes and rounded beneath. Disk of clypeus broader than high, lateral extensions reflexed although narrowly exposed in frontal aspect. Facial foveae rather large but punctiform. Mandibles tapering from broad base to acute apex and reaching a little beyond far margin of proboscidial fossa. Flanks of pronotum no more than normally impressed. Sculpture and pubescence similar to that of female but punctures and tessellation weaker. Face and cheeks almost entirely nude, hair of mesonotum very sparse and short, that onundersurf ace of head and thorax long and rather dense. Tergite 7 with a broad truncate apical lobe, slightly bisinuous across middle and with a short blunt tooth at outer corners. Subgenital plate with parallel sides and rounded apex, and about one and one-half times longer than wide; apical part of disk with very fine short pubescence. Aedeagus very small; dorsal lobes of caulis acute in both dorsal and lateral views; parameral lobes broadly strap-shaped and inserted low on sides of caulis; fused sagittae unusually slender, very thin dorsoventrally in lateral view and strongly curved upward. Length: about 3-3.5 mm.; anterior wing, 2.2-2.8 mm.