Andricus futilis form futilis

Cynips quercus futilis
Cynips quercus papillata
Cynips futilis
Cynips futiilis
Cynips papillata
Andricus papillata
Callirhytis futilis
Callirhytis papillatus
Andricus papillatus
Callirhytis papillata
Callirhytis quercus-futilis
Callirhytis quercus-papillata
Dryophanta papula

Galls. — Blister-like swellings (Figs. 28 and 29) of the leaf-blades, more or less globular, projecting only slightly on the upper surfaces, projecting in about half a hemisphere on the lower surfaces. Leaf-color, sometimes surrounded by a reddish ring on the surface of the leaf; about 3-7 mm. in diameter. Thin-shelled, hollow, with usually 2 or 3 small larval cells, distinct, central, connected with the outer wall of the gall by fine, silky, radiating fibers. On leaves of Quercus alba, Q. bicolor, Q. prinoides, Q. Prinus, and Q. stellata.

Range: Ontario, NH, MA, CT, NY, NJ, PA, DC, MD, OH, IN, IL, MI

Osten Sacken did not feel certain of the specific differences of futilis and of papillatus ; the main reason for which the two have been kept distinct is the reddish ring sometimes found around the galls called papillatus, and the different host plants of the two. I have compared the types of the two species and believe them to be identical. At the most, papillatus may be a host variety of futilis. As far as I can discover, the female of this species has not been previously described. It is quite variable as to shade of coloring.

The galls of futilis are first discernible about the middle of May, and are then to be found often very abundantly, on the white oak especially, sometimes occurring in numbers on a single leaf. The galls are at first so succulent that they are not easily bred; they should be gathered late in June and be placed directly on moist sand. The adults emerge from the last of June to the middle of July, leaving the empty galls now dry, hard, and brittle. The insects are positively geotropic and, after copulation, oviposit in the bark of the roots or the bases of the trunks of the white oaks.

- Alfred Charles Kinsey: (1920) Life histories of American Cynipidae^©

Reference: https://www.biodiversitylibrary.org/item/213997#page/25/mode/1up