Extracted from: Timberlake P. H., (1960). 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 IV. University of California Publications in Entomology Editors Volume 17, No. 1, pp. 1-156, plates 1-17.|
P. xanthodes is similar to luteola, but smaller, a little paler yellow in color, with a brown blotch on each side of the mesosternum, and a more hairy mesonotum in both sexes.
Female.—Canary yellow, with a quadrate brownish patch on each side of the mesosternum. Foveae of the face and second tergite black. Antennae yellow. The flagellum brown above, with a ring of darker brown on the second to fourth joints. Tegulae yellow at base and broadly hyaline on outer margin. Wings slightly whitish hyaline, the nervures and stigma pale yellow.
Head rotund, as long as wide. Proboscis moderately long, the galeae a little exceeding the proboscidial fossa. Facial foveae linear, about their own width from margin of eyes and reaching from level of upper margin of antenna! sockets nearly two-thirds of the distance to level of anterior ocellus. Pterostigma moderately narrow, and the parts of marginal cell beneath and beyond stigma about equal. Pygidial plate as long as the basal width, ogival at apex with a small median notch. Frons and mesonotum minutely tessellate, moderately shining, and with minute, rather sparse, and indistinct punctures. Pubescence sparse and whitish, the anterior part of mesoscutum with a few moderately long erect hairs. Length, 5 mm.; anterior wing, 3 mm.
Male.—Entirely yellow and much like the male of luteola, but smaller and having the mesonotum distinctly although sparsely hairy. Facial foveae punctiform. Genitalia similar to same parts of luteola, the parameral lobes appearing narrow in dorsal view, although they are much broader in lateral view than in luteola; fused body of the sagittae a little more elongate and more slender than in luteola, but with the apex blunter both in dorsal and lateral views. Length, about 4 mm.; anterior wing, 2.7 mm.