Phylloxera intermedia Pergande, n. sp.

The gall of this species appears to be intermediate between Ph. c. -septum and Ph. picta. Its inner construction resembles that of c. -septum on account of the presence of a rudiment of the central membrane, though its general form, especially in the larger specimens, is more like that of picta, from which, however, it differs in the much thicker walls and the absence of a nipple on the upper side.

The transverse diameter of this gall varies between 3 and 6 mm and its vertical diameter between 2 and 3 mm. The shape above is regularly convex in the larger galls and slightly conical in the smaller ones, and without a trace of a nipple or opening before maturity. On the under side it projects but slightly and is provided with a minute, but closed nipple, the insect issuing from the upper surface which splits in a more or less jagged, round or oval opening, the bracts of which curve more or less outward. In some few cases the nipple on the under side also opens sufficiently to allow the insects to emerge from both sides. The color of the galls above is reddish or yellowish, generally surrounded by a paler ring, and beneath paler than the leaf. It occurs on Hicoria alba [Carya tomentosa] in company with the other two, and matures from the end of May to the middle of June.

- Theo. Pergande: (1904) North American Phylloxerinae affecting hicoria (Carya) and other trees^©

Reference: https://www.biodiversitylibrary.org/item/114693#page/19/mode/1up