Neuroterus noxiosus form vernalis, new name
Galls. — Irregular clusters of woody swellings (Figs. 14 to 16) of the stems, petioles, and leaves. Polythalamous. The whole mass roughly about 20X40 mm. in diameter or less, inseparable from the plant; fist-like, the separate parts woody, indicating the separate leaves or parts of leaves involved, and bearing a small portion of deformed leaves; these parts are united by the deformed petiole, or by a fused mass of petioles or young twigs. The gall is bark-colored, or tinged with a glaucous bloom. Internally the larval cells are crowded closely together, the cells very distinct but not separable from the surrounding woody tissue. On the young growth of Quercus Prinus and Q. bicolor.
Range: MA, RI, CT, NY, NJ, New Brunswick, IL, IO, MI
When Bassett first described this species he gave detailed descriptions of the galls of the two generations and noted differences in sizes of the adults. The specific relations of the two generations had been arrived at through the field observation of the alternate abundance of the two forms of galls and the close similarity of the adults of the successive generations. The tremendous abundance of this species locally often gives abundance opportunity for observations. Gillette, Beutenmuller, Miss Clarke, Thompson, and other students of the family have made observations confirming Bassett’s statements, and there can be no doubt of the regular alternation of these forms, even though the data has not been checked by experimental work. This was the fourth and last in- stance of heterogeny discovered by Bassett.
The galls of this form appear when the young leaves first unfold in May and, like most of the spring galls of dimorphic species, grow very rapidly to maturity. The adults are known to emerge from June 12 to July 5. They occur in about equal numbers of the sexes: I counted 276 females and 233 males in one lot bred by Millett T. Thompson. After fertilization the females oviposit in the new wood of the twigs, usually not far from the galls in which they have developed.
