Cynips quercus foliata n. sp.

The Leafy Gall of the Live Oak. Another curious and by far the most interesting gall I have yet found in Florida, is that to which I have given the above name. Growing as it does in the bud axil of the leaf, and not unfrequently in close proximity to the others, the gall would naturally be taken by most observers for the blossom of the oak; indeed I never until lately suspected it to be the product of a Cynips.

On page 72, vol. 2, of "The American Entomologist," is figured a gall discovered by H. F. Bassett, so well known for his researches in this interesting branch of entomology, which will give one a fair idea of the species under consideration. At first I was inclined to believe my species and his, which he calls Cynips frondosa identical; but on a careful study of his description of the gall, (he does not characterize the insect producing it), I have no hesitancy in describing it as new.

Mr. Bassett found his species at Waterbury, Conn., on the Chincuapin Oak, Q. prinoides, while Walsh found it on the Bur Oak and White Oak; vide Proc. Entom. Soc. Phil. p. 68, 1864.

He says: "When mature it often attains a diameter of two and a quarter inches, and the modified leaves of which it is composed are then much longer and proportionally much wider than at first, so that instead of being what the botanists term 'lanceolate,' they become oval with their tips usually acute."

Bassett says: "The cells containing the larva are smooth, shining, oval, about one-eighth of an inch long."

Walsh also says: "The larger ones enclose four or five cells and when the gall becomes mature, the cells are gradually disengaged from their leafy matrix and drop to the ground, where no doubt the larva will pass the winter more agreeably among the masses of dead leaves, which accumulate in such situations, than it would do if it were exposed aloft to the stormy blasts, and the cold driving sleets of the dead season of the year."

Now, the largest specimen I have ever found of the present gall, and I have collected hundreds, is never more than three-quarters of an inch in diameter, and instead of the leaves being oval, they are strictly lanceolate; the cells or kernels too, instead of being smooth, are pitted, somewhat like a peach stone. They likewise never drop to the ground, but remain cemented to their cup, and the fly escapes by perforating a hole in the top. I have found hundreds of the black dry galls containing cells so perforated, and have never seen more than one cell to a gall.

Galls. — In outline urn-shaped, composed externally of numerous, lanceolate, leafy-like spines, developed from the axillary leaf bud; diameter one-half to three-quarters of an inch; internally consisting of a greyish acorn-like cup, with a single kernel imbeded half way; cup .20 inch in diameter. Kernel brownish .15 to .18 inch long by .07 to .10 wide, somewhat pointed at top and slightly contracted in the middle, irregularly pitted and grooved, somewhat like a peach stone only the grooves arc not so deep.

- William Ashmead: (1881) On the CYNIPIDOUS GALLS of Florida (1881)^©

Reference: https://www.biodiversitylibrary.org/item/32798#page/306/mode/1up