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.|
Male.—Head and thorax dark blue-green. Mandibles except red tips, labrum, entire face below level of antennae, anterior end of cheeks, and narrow postorbital line extending a little above middle of eye clear yellow. Pronotum yellow, with a green band from flank to flank. Abdo men yellow, with six dark-brown or blackish bands, that at junction of tergites 5-6 fainter or mostly restricted to an abbreviated band at apex of tergite 5; light band on tergite 1 moderately wide and interrupted medially. Exposed part of prosternum about half yellow; mesostemum with a small yellow spot on each side of anterior margin, or the spots evanescent or absent. Legs yellow including the coxae, but outer margin of hind tibiae and the hind tarsi pale brown. Scape and underside of pedicel clear yellow, the antennae otherwise brownish yellow, with dorsal side of flagellum narrowly pale brown. Tegulae broadly hyaline on outer margin and yellow at base. Wings hyaline, the nervures yellowish testaceous, the subcosta and margins of stigma pale brown.
Head rotund or only slightly broader than long. Mandibles simple, acute, and reaching the far margin of proboscidial cavity. Facial foveae faint, about twice as long as wide. Frons tessel late and opaque, with the punctures indistinct except when viewed obliquely. Mesonotum polished, with remote fine punctures. Pubescence white, about normal for group on cheeks and underparts of thorax, and rather short, erect, and sparse on mesoscutum. Subgenital plate about one and one-half times longer than wide, with the apex slightly rounded. Parameral lobes of caulis, ending acutely on underside, but the dorsal part almost wholly obscuring the underpart in dorsal view; fused part of sagittae distinctly angulate on each side before the acute apex. Length, 3.5-5 mm.; anterior wing, 2.8-3.2 mm.
Perdita interpreta ciliats subspecies of Bombus interserta
Female.—Differs from typical interserta in having the face marks more whitish, the first tergite black, with a preapical, interrupted yellow band, the front femora usually with a broad brown or fuscous mark behind, the front tibiae with a narrow, and middle tibiae with a broad dark streak behind, and posterior part of mesoscutummore closely punctured and hairy. Length, 5 to almost 6 mm.; anterior wing, 3.8-4 mm.
Male.—Differs from interserta in having dark marks on posterior side of front femora, and on front and middle tibiae, and sometimes dark streak on dorsal margin of hind femora; pre apical yellow band on tergite 1 usually very narrow and broadly interrupted, or sometimes almost absent, and yellow spot on each side of anterior margin of mesostemum almost invariably ab sent; genitalia much as in interrupta except that the apical fringe of the parameral lobes is much longer. Length, 4.5-5.5 mm.; anterior wing, 3.2-3.6 mm.