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.|
P. mentzeliae is the darkest of the species described by Cockerell from the flowers of Mentzelia. In the female the white face markings are restricted to small lateral marks; in the male the yellow of the face does not go above the antennae, except on each side, and usually there is no yellow on the under parts of the thorax. The form with the dark markings on the legs and abdomen reduced or evanescent was described by Cockerell as pallidior and pulchrior (the latter macrocephalous), but since both dark and light forms often fly together there is no reason to regard them as more than varieties, although there may be some evidence to indicate that the dark form is more prevalent northward. The type locality of mentzeliae is Santa Fe and both pallidior and pulchrior were described from Albuquerque, New Mexico.
Female.—Head and thorax dark green; clypeus, supraclypeal area, mesoscutum except anterior border, and scutellum, black. Tubercles of pronotum and lateral face marks, creamy white; the latter rarely evanescent, usually more or less quadrate, and not reaching above level of summit of clypeus (except in var. pallidior). Abdomen fuscous above with narrow enclosed white bands or the bands broad enclosed on tergites 2 to 4 or 5 j often with a white mark on tergite 1, which may either take the form of an abbreviated band on the disk, be more or less interrupted, or extend broadly and irregularly forward down the middle; the light bands on following segments sometimes enlarged and open at outer ends; apical tergites usually and venter whitish. (In var. pallidior the abdomen may become entirely light except for four spots on tergite 1.) Legs fuscous; trochanters more or less, apex of front and middle femora together with their tibiae and tarsi except for a dark patch on posterior side of middle tibiae, pale yellow or yellowish white. (In var. pallidior, legs sometimes entirely light, or with dusky shading on anterior side of front femora and on outer side of middle and hind tibiae.) Antennae pale fuscous or brown above, including a spot at apex of scape, scape otherwise pale yellow, and underside of flagellum dull yellowish. Mandible reddish on apical half and white at base. Tegulae subhyaline with a basal white mark. Wings milky hyaline, nervures pallid, stigma more or less yellowish.
Head only slightly longer than wide, with large protruding clypeus. Facial f oveae generally slender although somewhat wider than space between them and eyes and about two-thirds as long as space between antennal sockets and anterior ocellus. Mandibles stout, tapering, with small inner tooth, and reaching far margin of proboscidial fossa. Proboscis moderately long but included within fossa, apex of galeae not quite reaching base of stipites. Pterostigma large, but not so broad as first submarginal cell; parts of marginal cell beneath and beyond it about equal. Pygidial plate triangular, slightly longer than wide, and with narrowly rounded apex. Head and thorax moderately shining, with fine tessellation distinct except on clypeus, and minute punctures widely scattered on f rons and anterior half of mesoscutum. Pubescence whitish, very sparse and short on face and mesonotum; longer and more abundant on underside of head and thorax. Length: about 5-6.25 mm.; anterior wing, 3.8-4.5 mm.
Male.—Head and thorax dark green, becoming black on disk of mesoscutum and scutellum. Anterior third to one-half of undersurf ace of head and cheeks, mandibles except red tips, labrum, and face to level of antennae, with lateral marks extending bluntly to foveae, bright yellow. Collar and hind margin of disk of pronotum, tubercles, lower end of flanks of pronotum, and very rarely a small spot on anterior part of mesopleura, yellow. Abdomen fuscous on tergites 1 to 3 or 5, or with suffused yellow bands on tergites 2 to 4, otherwise yellow. (In var. pallidior often entirely yellow or orange yellow except on basal declivity of tergite 1.) Legs yellow, with hind tibiae and tarsi mostly brown, and hind femora brown behind except at apex (varying to entirely yellow in var. pallidior). Antennae clear yellow, with flagellum pale brown above in typical form. Tegulae and wings as in female.
Head often more or less enlarged, sometimes becoming very large and quadrate, with lateral plates of face much broader than intervening area. Cheeks more or less broad and armed anteriorly with a conical process. Mandibles tapering from broad base to very acute apex, and in extreme macrocephalous examples each reaching almost to base of other. Facial f oveae puncti-form. Pronotum deeply impressed on flanks; posterior corners of disk prominent and rounded; lateral margins of disk more or less strongly emarginate as seen from above. Sculpture and pubescence much as in female. Tergite 7 with moderately narrow apex. Subgenital plate triangular, acute and keeled on outer side at apex, and with fine short pubescence on apical half of disk. Genitalia much as in wootonae, but dorsal lobes of caulis more truncate at apex. Length: 4-5 mm.; anterior wing, 3.2-4 mm.
This species has been previously recorded from Santa Fe, Albuquerque, Raton, and near Tularosa, New Mexico, and from Antonito, Colorado.