Erythres jaculi, n. sp.
Agamic form

[Genus level description: Gall. — A. separable, cone-like, terminal cluster of aborted, fasciated leaves and bracts enclosing a small, seed-like cell. The cluster composed of many, awl-shaped bracts and aborted leaves, the inner leaves elongate, narrow, awl-shaped, with sharply-pointed tips, each terminating in fine filaments, the outer bracts short, more broadly triangulate; the whole forming an elongate or swollen cone; fresh galls probably green in color, dried galls straw to medium brown, weathering more silvery gray; the galls up to 25,. mm. in length and 13. mm. in greatest diameter, internally the larval cell is small, tip to 6.0 mm. in length and 2.0 mm. in greatest diameter, elongate spindle-shaped, sharply tipped, thin-walled, and closely embedded in the surrounding bracts. Highly separable galls, borne terminally on main or lateral stems.]

Gall. — A swollen, very compact cone of fasciated leaves, with the greatest diameter near the base, with the apex of the gall drawn to a blunt point; up to 25. mm,, averaging near 20. mm. in length, up to 13.0 mm, averaging near 11. mm. in greatest diameter.

Host. Q. Rossi;, a larger tree-form or black oak with large, coarsely reticulate leaves. Possibly on other black oaks of the area.

Rango. — Jalisco: Sayula, 13 SW, 7700’ (types). Possibly widely spread through a southwestern portion of Mexico which includes the state of Jalisco

Life History. — Adults: March 20.

This insect, jaculi, is different enough from hastata. It is most distinct in its almost uniformly sooty black mesonotum, its conspicuously broader head and thorax, and the much more compact gall — a cone which is broadest -at base and printed at top.

Erythres jaculi

[Genus level description:] The galls are monolocular and very peculiar in shape, represented by cone-like clusters, each gall of which enclosing a small larval cell (Fig. 3). They are some similar to the cone-like galls which are induced by some Cecidomyiidae (Diptera), Andricus quercusfoliatus (Ashmead, 1881), A. stropus Ashmead, 1887 and A. cinnamomeus Ashmead, 1887 from the Nearctic; A. foecundatrix (Hartig, 1840) from the Western Palaearctic and A. mukaigawae (Mukaigawa, 1913) from the Eastern Palaearctic, nevertheless, the adults of Erythres are quite distinct from all of mentioned species. The other very important difference between Erythres and mentioned Andricus species are the host oaks. Erythres species are known only from red oaks (section Lobatae of Quercus L.), while all the listed Andricus species are associated with white oaks only (section Quercus of Quercus).

Erythres includes two species: E. hastata and E. jaculi. Both species are very similar. The galls are different in shape but associated with the same oak host. Erythres hastata has an elongated gall and was collected by Kinsey on Q. castanea Née (= Q. serrulata Trel.) known from Michoacán and Zacatecas (Figs 3a, c) and E. jaculi has a thicker gall also on Q. castanea (= Q. rossii Trel.) known from Jalisco (Fig. 3b).

Erythres jaculi and E. hastata are morphologically very similar, as we have commented, and have the same host, then, it is possible that they could be the same species; nevertheless, we accept both species since they have different shape of galls (Fig. 3). More E. jaculi specimens must be studied in order to solve this problem. Since Kinsey descriptions, only E. hastata was collected from Q. eduardii Trel. (Fig. 3c) and Q. viminea Trel. (Pujade-Villar et al., 2013: Fig 3a). These two new host records with the earlier known one, Q. castanea, all belong to the section Lobatae of Quercus L., and thus Erythres related only to the red oaks. Quercus eduardii and Q. viminea are known only from Mexico, while Q. castanea is known also from Guatemala and El Salvador (Govaerts & Frodin, 1998) and thus it is possible that Erythres species can be found south of Mexico also.