Extracted from: P.H. TImberlake. 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 III). University of Caifornia Press Berkeley and Los Angeles 1958|
P. polita is easily distinguished from other species of this group by its polished sculpture and the broad white abdominal bands, which are interrupted medially. It was based originally on a specimen from the Baker collection, which has the thorax partly washed with brown, the dark parts of the abdomen brownish, and the light band on the fourth segment incomplete, but more normal specimens are colored as described below.
Female.—Head and thorax shining dark blue, the mesonotum slightly greenish. Base of mandibles, clypeus more or less, and lateral marks yellowish white, the mandibles shading into testaceous at middle and red at apex. Labrum and clypeus testaceous brown, the latter with three white marks on upper two thirds of disk, or mainly white with dark anterior margin and two irregular dark stripes on upper part of disk. Lateral marks twice as wide below as at upper ends, obliquely truncate between lower end of foveae and margin of eyes and separated from clypeus by a black interval, but sometimes abbreviated and narrowed to become nearly uniform in width above and below. Collar, posterior border of disk of pronotum, and tubercles yellowish white, with the light and dark bands on disk about equal, or the posterior light band sometimes narrowed at middle or interrupted. Abdomen fuscous, with a broad and narrowly interrupted white band on tergites 1 to 4 (rarely on only tergites 2 and 3) reaching the lateral margins on all segments, the pygidial plate amber testaceous. Legs fuscous, the apex of front and middle femora, and front and middle tibiae and tarsi, except posterior side of the tibiae, white. An¬tennae pale brownish fuscous, the underside of scape and pedicel yellowish white, the underside of flagellum pale yellowish. Tegulae whitish at base and almost clear hyaline on outer margin. Wings somewhat dusky hyaline, the nervures and margins of stigma testaceous brown, with the subcosta darker brown.
Head distinctly broader than long. Mandibles moderately slender, with inner margin abruptly narrowed close to apex to form a distinct tooth. Facial foveae rather narrow and well im¬pressed, subacute at lower end, with inner margin receding from the eye margin, the interval between them and margin of eyes otherwise not more than half their width, and their length about equal to two thirds of distance between antennal sockets and anterior ocellus. Pygidial plate a little longer than the basal width, with the sides converging to the rather narrow, rounded, or subtruncate apex, which has no median notch. Head and thorax polished, the frons with a barely discernible tessellation and very fine punctures in the area adjacent to the foveae and a few remotely scattered punctures in front of the ocelli. Pubescence white, short, and erect, that on the mesonotum very thin; frons and vertex almost entirely nude, except in a small area between each fovea and adjacent antennal socket. Length, 4-4.5 mm.; anterior wing, 2.8-3 mm.
Male.—Head and thorax dark blue. Mandibles except red tips, labrum, face below level of antennae, and antennae yellow, with blue of f rons intruding slightly on each side between the lateral and subantennal marks, or more rarely the outer and lower margin of the subantennal plates dark. Lateral marks of face ending rather obtusely just above middle of inner orbits of eyes. Pedicel and flagellum of antennae narrowly dilute fuscous above. Thorax dark except pale yellow tubercles, collar, and cuneate mark on each side of posterior margin of disk of pronotum. Abdomen fuscous with a pale yellow band on tergites 1 to 6, the light bands often broadly emarginate behind on each side, and those on tergites 1 to 4 sometimes narrowly interrupted medially (that on tergite 1 rarely divided into four spots). Apex of tergite 7 pale ferruginous. Venter dilute fuscous with a narrow pale yellowish band on four or five of the intermediate segments. Legs pale yellow, the hind coxae except beneath, the front and middle femora except broadly at apex and beneath, the hind femora except at apex beneath, and hind tibiae and tarsi fuscous. Tegulae hyaline on outer margin and yellowish white at base. Wings faintly dusky hyaline, the nervures and margins of stigma pale sepia.
Head rotund, barely broader than long. Mandibles simple, tapering and reaching far margin of proboscidial fossa. Facial foveae faint, about twice as long as wide. Head and thorax shining, the f rons and vertex minutely tessellate and with sparse minute punctures. Mesoscutum and scutellum polished, with very fine remote punctures. Abdomen moderately robust, somewhat broader than the thorax. Pubescence white, moderately thin, erect, and rather short, that on the mesonotum short and sparse. Subgenital plate somewhat less than twice as long as wide, with apex rounded and the lateral margins somewhat incurved. Parameral lobes of aedeagus short, with the apical margin of ventral half emarginate and the ventral margin produced into a short pointed process; sagittae very short, the fused part about two and one-half times longer than wide and acute at apex. Length, about 3-3.45 mm. anterior wing, 2.5-2.8 mm.
One female (holotype), Tulare, Tulare County, California, Aug. 5,1897 (A. P. Morse), Baker No. 2364; allotype and paratypes on Semisonia pungens as follows: 2 females, Turlock, Stanis¬laus County, June 10, 1952 (J. I. Stage) and Aug. 8, 1954 (R. R. Snelling) ; 9 males, 4 females (including allotype), 10 miles southeast of Angiolo, Tulare County, June 5, 1957 (Snelling); 1 male, 1 female, 8 miles northwest of Hanford, Kings County, June 13, 1957 (Snelling) and 4 males, 2 females, 8 miles northeast of Hanford, June 20, 1957 (Snelling).
Type in collection of the T7. S. National Museum (No. 43,417) ; allotype and five paratypes in collection of the Citrus Experiment Station, Riverside, and the remainder of paratypes in collection of Messrs. Stage and Snelling.