Extracted from: TImberlake P. H., (1958). 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 California Press Berkeley and Los Angeles 1958, Volume 14, No. 5, pp. 303-410, plates 4-15.|
P. scotti is one of the more distinct members of the zonalis group not only in the unusually large size but in structure and peculiar markings. Although the sub-genital plate has a large subquadrate expansion on the apical half, scotti does not appear to be particularly closely related to the other three large species, tovmsendi, ericameriae, and chrysothamni. Both sexes of scotti have the eyes coppery red.
Female.—Head and thorax dark blue-green, the mesonotum a little more yellowish green. Mandibles except the dark red apical third, labrum, clypeus, and lateral marks pale yellow; labrum with a dark mark across the base, and clypeus with two brownish fuscous stripes on disk between the usual pair of dots, these stripes broad below, tapering to a point above and not reaching the dorsal margin of disk. Supraclypeal area and subantennal plates black. Pronotum green, with the collar, interrupted band on hind margin of disk, and the tubercles yellow. Abdomen pale yellow or almost creamy white, with five blackish bands; that part of bands at apex of tergites 2 to 4 not reaching the lateral margins, but part at base of each subsequent segment curved backward to the margins and that at apex of tergite 4 with a broad anterior bulge near outer ends; tergite 1 broadly pale yellow subapically and on the sides of the base, the basal black mark bowl-Bhaped, with the basin of the bowl very broad and evenly transverse across its base and enclosing a broadly oval dark spot on each side adjacent to the rims; tergite 5 with a subapical oval black mark on each side, and its broad apical depression and the pygidium of tergite 6 amber color. Legs pale yellow, the front coxae, all femora except at apex, and a broad stripe either above or in front, apical two thirds of posterior side of middle tibiae, a little more than apical half of hind tibiae except dorsal margin, and small joints of hind tarsi blackish. Scape of antennae except a dark spot above at apex, underside of pedicel and of one or two following joints yellow, the rest of flagellum brownish yellow beneath, and antennae otherwise blackish. Tegulae subhyaline, the basal margin yellow. Wings almost whitish hyaline, the nervures pale yellowish, the subcosta and margins of stigma pale brown.
Head distinctly broader than long, with the inner orbits slightly diverging below. Mandibles massive, strongly curved, and somewhat blunt at apex, the inner margin dilated, with the dilation ending abruptly some distance from apex. Facial foveae broad and well impressed, diverging a little from eye margin below, and reaching from lower level of antennal sockets a little more than two thirds of distance from the sockets to level of anterior ocellus. Marginal cell of wings with part beyond stigma about one third longer than the part beneath. Pygidial plate about as broad as long, with the sides ogivally converging to the moderately wide apex, which is distinctly notched. Frons tessellate, moderately dull, and with fine punctures that areclose below and sparse in the area adjacent to the ocelli. Mesonotum polished, with moderately sparse fine punctures. Pubescence whitish, about normal for group, with that on mesonotum rather short and presumably normally erect but matted down in type. Length, 8 mm.; anterior wing, 5 mm.
Male.—Dark blue-green, with bright yellow markings, including mandibles except red tips, labrum, face below level of antennae, anterior end of cheeks, and postorbital line along anterior two fifths of eyes; lateral marks of face ending very acutely above, nearly at level of foveae and oblique from that point to outer upper margin of subantennal plates. Pronotum dark, with the collar, a small spot on anterior margin of the flanks, large transverse mark on each side of hind margin of the disk, and the tubercles yellow; sometimes mark on tubercles narrowly confluent with adjacent mark on disk. Abdomen yellow, with each segment banded or otherwise marked with black; tergite 1 dark with the preapical yellow band interrupted or reduced to a small spot on each side; black bands on tergites 1 to 4 with a broad anterior bulge on each side about its own width from lateral margin of segments; tergites 5 and 6 with a subapical, oval dark mark on each side, the base of tergite 6 with a distinct dark band, and tergite 7 dark at base only close to lateral margins but with a large nearly circular dark mark on each side of the disk; venter except first segment almost entirely pale yellow. Legs yellow, with a broad blackish streak on posterior side of all the femora and a narrow streak on anterior side of hind pair; middle and hind coxae dark except at apex and the hind pair yellow also on underside to base. Antennae nearly black above, including small spot at apex of scape, the scape otherwise and pedicel beneath clear bright yellow, the flagellum more orange yellow beneath. Tegulae and wings as in female.
Head somewhat broader than long. Mandibles tapering to acute apex and reaching far margin of proboscidial fossa. Facial foveae faint, about twice as long as wide. Frons minutely tessellate, dull and minutely closely punctured. Mesonotum polished, with moderately sparse punctures. Pubescence white, thin on the mesonotum, and longer and denser on the cneeks and underparts of thorax. Expanded apical part of subgenital plate a little obtusely produced and widened on each side at base, and the apex obliquely truncate on each side of the median line. Basal orifice of caulis of aedeagus enclosed by very broad rims; the mediodorsal lobes of caulis ending in rather narrow blunt points which fall a little short of apex of the parameral lobes; fused part of sagittae moderately narrow and tapering not far beyond middle to the acute apex. Length, 6.7 mm.; anterior wing, 4.8 mm.
One female, 2 males (holotype female, allotype, and paratype), Fort Tejon, Kern County, California, Oct. 20,1938 (F. T. Scott), in collection of the Citrus Experiment Station, Riverside.