Femuros ruidum, n. sp.
Agamic form

Gall. — As described for the genus. Not distinct from the gall of repandae unless in its larger size; up to 23. mm,, averaging nearer 15. mm. in diameter.

[Description for the genus: Large, globular, monothalamous bud galls. Galls quite regularly spherical, distorted chiefly by the bracts, deformed leaves, and deformed (broadened) petioles which are closely fused on the surfaces; up to 23, averaging near 15. mm. in diameter; the surface of the gall similar to the bark covering young twigs, touched with red when young, becoming silvery and purple brown with age. Internally more or less solid, with a compact but soft tissue filling the outer third or half of the gall, this giving way to a more spongy and open tissue which supports the larval cell; larval cell central, inseparable, thick- and hard-walled, up to 7.0 mm, in diameter even in rather small galls. Galls terminal on main or side twigs, abruptly rising from the twigs, sessile but not more solidly attached than a normal bud; usually showing normal bud scales at base, occasionally with a deformed or small leaf or even a rare stem developing from the aborted structures on the surfaces of the galls; occurring singly or (rarely) in clusters of two or three galls.]

Hosts. — Quereus texcocana [deserticola], Q, conglomerata Q, rhodophlebia [rugosa]. Apparently on all the white oaks of the area except the low dwarfs of the repanda group.

Range. — Mexico: Mexico City, 20 S? 4200‘ (Q. rhodophlebia ). .Mexico City, 17 S, 8200’ (Q, conglomerata , Q. texcocana. Mexico City, 12 W, 8500’ (Q. texcocana). — .Morelos: Cuernavaca, 8 N, 8700’ (Q. texcocana, types; also on Q, conglomerata ). — Apparently one species both in the Valley of Mexico and in Morelos, possibly extending further west toward Michoacan and south east toward Vera Cruz.

Life History. — Adults: March 5, 15, 20, 29. April 5, 10.

In several groups of cynipids we find that the species occurring on the inner faces of the mountains rimming the Valley of Mexico do not extend over the high passes onto the southwest slopes which drop into the valleys of Morelos. In the present Instance, however, it seems to be one species, ruidum which we found on the several oaks in localities south and west of Mexico City, and in the montnins above Cuernavaca In Morelos. Having crossed the high divides at this point, the species may extend some hundreds of miles to the west into Michoacan and, southeastwardly, toward Vera Cruz.

- Alfred Kinsey: (1937) New Mexican gall wasps (Hymenoptera, Cynipidae)^©