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 Caifornia Press Berkeley and Los Angeles 1958, Volume 14, No. 5, pp. 303-410, plates 4-15.|
This elegant species from Utah runs definitely to Procockerellia in my key (Univ. Calif. Publ. Bntom., 9:346-348). In color and many of the following characters excellens agrees and some ways differs from the two previously known species of Procockerellia.
Mandibles dilated within with a stout incurved apex, the incurved part shorter than in albono-tata, but mandibles may be somewhat worn. Proboscis elongate, probably reaching in repose well beyond front coxae, the galeae considerably longer than the stipites, and the maxillary palpi five-jointed. Pterostigma moderate in size, definitely narrower than in stephanomeriae and albonotata. Facial foveae well impressed and linear. Scopa of hind tibiae rather thin, much thinner than in the other two species, the hairs fine and moderately crinkly, the longest ones about twice as long as width of tibia. Lateral ocelli about as far from margin of eyes as their distance apart; in the other two species slightly closer to eyes than their distance apart.
Female.—Head and thorax dark blue-green, the mesonotum black except anterior border of the scutum. Mandibles at base, clypeus, lateral, supraclypeal, and subantennal marks creamy white; clypeus with usual dark dots and two submedian arcuate black stripes which enclose an oval white mark, or the stripes sometimes confluent to form an almost solid black mark; the other white marks separated from each other and the clypeus by distinct black sutural lines; supraclypeal mark twice as broad as high; subantennal marks obliquely subquadrate; lateral marks very large, triangular, much higher than wide, rounded at inner corner adjacent to clypeus, with the inner margin straight and the upper angle acute and intruding between foveae and margin of eyes. Collar of pronotum, band on hind margin of disk, cuneately widened at outer ends, and the tubercles white. Abdomen black, the pygidial plate ferruginous; a small white mark on each side of disk of tergite 1, and a broad white band on tergites 2 to 4; the bands bent backward at outer ends and reaching lateral margins, that on tergite 2 narrowly interrupted in middle. Legs blackish, the apex of front and middle femora, the front and middle tibiae except a dark blotch behind and above, and front and middle tarsi yellowish white; knees of hind legs testaceous and hind tarsi pale brown. Antennae fuscous above, the scape white beneath and at base, the flagellum dull yellowish beneath. Tegulae yellowish at base and hyaline on outer margin. Wings whitish hyaline, the nervures pale yellow, the apical half of subcosta tinged with
Head broader than long, with clypeus moderately prominent. Disk of clypeus slightly longer than wide, the lateral extensions about as long transversely as the disk, and about one third of the disk anterior to a line tangent to anterior margin of lateral plates of face. First joint of labial palpi reaching middle of the galeae; maxillary palpi rather short, the first joint longer and thicker than following joints, the second and third a little shorter than the fourth and fifth joints. Facial foveae narrow, close to eye margin except at lower end, and reaching from level of antennal sockets about three fourths of distance to level of anterior ocellus. Pygidial plate large, the truncate apex about half as wide as the base. Head and thorax smooth and shining with moderately close punctures; punctures of face coarse, those of frons about one to two puncture widths apart and those of vertex sparser; punctures of mesoscutum fine and about two to five puncture widths apart. Pubescence white, moderately abundant, the hairs of mesonotum moderately short and erect. Length nearly 8 mm.; anterior wing, 4.9 mm.