Phylloxera Caryae-ren Riley.

Since the description of this gall nothing new has been added regarding its earlier stages and development ; nor have I had the opportunity of studying its architects.

The galls usually grow, like those of the preceding species, in clusters, though occasionally singly, upon the main petiole, the leaf -stems or the midrib of the leaves of Hicoria glabra, usually along the underside. Frequently, however, they are so closely crowded together as to completely encircle the petioles, never becoming confluent, however. They are always placed transversely with the axis of the petiole, more or less distinctly reniform and divided along their entire transverse length in two equal halves or lids, the edges of which are incurved and pressed closely together while young, but spread open for some distance when mature to allow the insects to escape. The size varies from 2-15 mm and the outer surface is densely pubescent and of a pale green color, with the interior smooth and yellowish-brown. The walls are rather thick and hard and similar in composition to the husks of the nuts.

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

Reference: https://www.biodiversitylibrary.org/item/114693#page/79/mode/1up