Neuroterus fusifex Pujade-Villar, In Pujade-Villar et al. (2016b: 77)

Gall (Figs. 6h-i): Multilocular gall, located in catkins, ovoid (7-12 mm long and 5-7 mm wide) or at the petiole and base of the leaves (new location). In catkins, it causes hypertrophy of the axis; the anthers of some flowers protrude. When young, it is green and turgid, hardening and turning purple-red upon maturing. The surface is provided with a thin, dense whitish pubescence. Inside are numerous rounded larval chambers (0.5 mm in diameter) arranged together, bound with a hard consistency. The medullary space between the larval chambers hardly exists.

Hosts: Quercus laeta and Q. rugosa (section Quercus).

Biology: Species is known only from the sexual generation. Galls appear in April when catkins and leaves begin to develop. Adults emerge at the end of April or beginning of May. Most of the galls fall to the ground shortly after, although some can remain on the tree for a few more months.

Distribution: Mexico (State of Mexico); first record for Santa Fe (Mexico City) on Q. laeta.

Neuroterus fusifex Pujade-Villar and Ferrer-Suay n. sp.
(Figs 1–3)

Gall (Fig. 4a-b). Multilocular gall, located in catkins, ovoid (7-12 mm long and 5-7 mm wide). It is caused by the hypertrophy of the axis with anthers of the some flowers are protruding. When young it is green and turgescent, which hardens and becomes violet-red at maturity. The surface is provided with a thin, dense whitish pubescence. Inside numerous rounds larval chambers (0.5 mm in diameter) are closely disposed ones together with each other, jointed with a hard consistency. The medullar space between larval chambers hardly exists.

Host plant. Quercus laeta Liebm. (section Quercus) endemic from Mexico.

Distribution. Mexico (Cerro de las Campanas - Arenales, San Felipe del Progreso, Estado de México).

Biology. Only the sexual generation is known. The galls appear in April on catkins. Adults emerge in the last April or early May. The galls fall to the ground shortly after although some can remain in the tree some more months.