Andricus mogollonensis Melika, Nicholls & Stone, sp. nov.

Diagnosis. The gall resembles sexual generation pip galls induced by the sexual generations of Disholcaspis Dalla Torre & Kieffer, 1910 and Acraspis Mayr, 1881. No other Andricus species from Arizona is known to induce such a gall. In A. mogollonensis the tarsal claws are simple, thus it is Callirhytis sensu Burks (1979). No species of Callirhytis are known from AZ, NM which induce bud galls on Q. gambelii or other white oaks.

Gall. (Fig. 193). A tiny chestnut brown, unilocular pip gall in axillary buds. The gall is a smooth thin-walled ‘pip’ gall, comprising only the larval chamber, reaching 3–4 mm long by 2 mm in diameter, with a blunt rounded apex.

Biology. Only females are known, whose morphology most closely resembles asexual generation females (genae are broadened behind the eye, visible in front view). However, this character alone is inadequate to confirm that this is an asexual generation. Mature galls were collected in April from Q. gambelii; adults emerged soon afterwards. This spring developmental phenology is more compatible with a sexual generation. In addition, the gall morphology of a bare larval chamber on a bud is more typical of a sexual generation gall.

Distribution. USA, Arizona: Chiricahua Mountains, Mogollon Rim

Quercus arizonica, gambelii
Bud galls
Conical, thin-walled, straw-yellow, in early spring. Fig. 26.