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.|
Only the female of this species is known, but it is so similar to exilis in structure and habits that there is no doubt that it is closely allied. The female is slender and entirely ferruginous yellow -almost exactly the same color as the male of P. minima Cockerell.
Female.—Head, thorax, and abdomen, dark orange yellow; foveae of face and second tergite black. Legs and antennae concolorous, flagellum pale fuscous above, mouthparts concolorous, apex of mandibles red. Eyes gray to blackish in dry specimens. Tegulae pale testaceous at base and subhyaline on outer margin. Wings clear hyaline, nervures pale testaceous, subcosta and stigma yellowish.
Form unusually slender. Head distinctly longer than wide; face strongly convex; clypeus strongly projecting, prominent, and with apex of disk truncate. Cheeks broad posteriorly, but becoming obsolete opposite anterior end of eyes. Occipital concavity very small and shallow. Lateral ocelli nearly as distant from occipital margin as from summit of nearest eye. Eyes unusually narrow, much more than twice as long as wide. Facial foveae linear, hardly more than half as wide as interval between them and margin of eyes, and reaching from level of middle antennal sockets about halfway to level of anterior ocellus. Antennae a little longer than usual, middle joints of flagellum distinctly longer than thick. Mandibles moderately stout, abruptly narrowed on inner margin before the acute apex. Proboscis rather long, but not surpassing the elongate fossa, the tip of galeae almost reaching base of stipites in repose. Ptero-stigma short and broad, about twice as long as wide, and as wide as first submarginal cell. Second submarginal cell narrowed one-half above. Marginal cell short, no longer than stigma; part beyond stigma broader and shorter than part beneath. Sides of pygidial plate converging to narrowly rounded apex. Head and thorax shining, impunctate, with very faint tessellation on frons and mesonotum. Undersurf ace of head and sternum of thorax with thin, short, erect, whitish hair, becoming longer and denser on front coxae; head and thorax otherwise virtually nude, except very sparse and short hair on clypeus and anterior part of mesoscutum. Length: about 3.4 mm.; anterior wing, 2-2.3 mm.