Neuroterus stonei Melika & Nicholls, sp. nov.

Diagnosis. Neuroterus stonei belongs to Kinsey’s subgenus Diplobius. The only other Neuroterus species that is known from the southwestern USA that induces bud galls in its sexual generation is N. alexandrae, although galls of that species have only been found to date on Q. tubinella while N. stonei galls the oaks Q. gambelii and Q. arizonica.

Gall. (Fig. 434). A small unilocular bud gall, spherical, reaching 4–5 mm diameter, that develop in terminal and lateral buds. The lower quarter to third of gall has a few bud scales around it. Gall is initially pale green with some darker green markings, becoming pinkish with darker red or purple lines as it matures. Similar in structure to the sexual generation of N. alexandrae on Q. turbinella. Possibly the same as the undescribed gall pictured in Fig. 22 of Weld (1960).

Biology. Only a sexual generation is known, which induces bud galls on Q. arizonica and Q. gambelii.

Distribution. USA, Arizona: Chiricahua Mountains, Mogollon Rim area south of Flagstaff.

Quercus arizonica, gambelii
Bud galls
Globular, green with purple stripes. July. Fig. 22.