Neuroterus perminimus (sexgen)

Callirhytis perditor (agamic)

Neuroterus perminimus

The galls of this species are scarcely 1 mm. long and 1 mm. wide and 1 mm. deep. They lie embedded in the lamina of white oak leaves, are pustule-like in form, and oval and apparent on both sides of the leaf, though more distinctly on the upper than on the under side. As many as two hundred of them may be found on a single leaf of ordinary size. Since many of the individuals become infested with parasites, very few of the hosts ever reach maturity. The galls mature about the 25th of June and the imagos hatch out before July 10th in Ohio. 

Andricus perditor

The galls of this species are 3 to nearly 4 mm. long and 2.5-3 mm. broad. The base is broad, the apex conical, the base with the cicatrix of a true acorn. They occur in among the acorns of Quercus ilicifolia in the Spring of the acorns' second year's growth, at which time the latter are very like these galls in appearance. 

Guide to the insects of Connecticut. Part III. The Hymenoptera, or wasp-like insects of Connecticut