Andricus (Callirhytis) pilula, n. sp.

Small, round, thin-shelled galls on the blade of the leaves of Q. undulata, collected in southern Utah by Mr. Siler. They are usually situated near the margin of the leaves and always on one of the principal leaf veins, and project equally above and below the surface. The average size is only .15 of an inch in diameter. The galls resemble those of Neuroterus utricula Bass, more nearly than any other species known to me. I found twenty-five or thirty specimens in a box of A. Sileri, and was so fortunate as to find two of them that, though perforated, still contained the gall-flies. These were both females, quite perfect, and the description that follows will, no doubt, well agree with more recent specimens.

Quercus gambelii
Leaf galls
Integral
Gall like Fig 103 [Andricus pilularis]

Andricus pilula

Small, round, thin-shelled galls on leaf blades, usually near the margin and always on the upper leaf veins, projecting on both surfaces, diameter 3.7 mm, on Quercus undulata.

Andricus pilula

This species was described from two females cut from galls from southern Utah. The types have the claws toothed, not simple as described. Similar galls were collected by Dr. A. W. Grundmann on Quercus gambelii in the mountains near Salt Lake City, Utah, and both females (agreeing with the types) and males were reared June 1-5, 1949. A description of the male is given below.