Andricus archboldi Melika & Abrahamson, sp. nov.
Asexual generation

Diagnosis. Galls of the asexual generation very closely resemble the galls of C. quercusclavigera (Ashmead, 1881), and C. quercuspunctata; the former species is known to associate with Q. myrtifolia, a closely related species to Q. inopina. The galls of these three species are difficult if not impossible to distinguish. However, we never found the galls of A. archboldi on Q. myrtifolia. Furthermore, galls induced by C. quercuspunctata and C. quercusclavigera were never found on Q. inopina. Developing galls of C. quercusclavigera appear very similar to asexual galls of A. archboldi, however, at maturity the larval cells of C. quercusclavigera emerge through the bark of the gall and drop to the ground. The larval cells of A. archboldi remain inside the gall at maturity and the adults chew through the gall tissues to emerge.

Gall (Fig. 30). Large abrupt, rounded and multilocular stem swellings encircling woody stems. The gall has a cheese-like texture when young and actively growing, but becomes woody and hard at maturity. The larval cells never emerge through the surface of the gall. The gall is 2 to 4 cm in diameter and height.

Biology. Both generations have been found exclusively on Lake Wales Ridge in Florida, on an endemic oak, Q. inopina. Final instar larvae overwinter in the galls and pupate in March. Asexual females begin to emerge in early April and are fly actively throughout the month, laying eggs that result in integral leaf galls also on Q. inopina. These sexual generation leaf galls grow through the autumn and mature in November. Adults of the sexual generation emerge in December.

Distribution. USA, Florida only, Highlands Co., Lake Wales Ridge endemic; quite common at the Archbold Biological Station, Lake Placid.

- George Melika, James Nicholls, Warren Abrahamson, Eileen Buss, Graham Stone: (2021) New species of Nearctic oak gall wasps (Hymenoptera: Cynipidae, Cynipini)^©