Feron cylindratum (Kinsey, 1937), comb. nov.

Xystoteras cylindratum Kinsey 1937a: 77, female, gall.
Liodora cylindratum (Kinsey): Melika & Abrahamson 2002: 160 (synonymized Liodora with Andricus); Pujade-Villar 2003: 234 (mentioned this combination).
Andricus cylindratum (Kinsey): Pujade-Villar 2003: 234.

Gall (Fig. 161). Small, naked, hollow cylinders scattered on the underside of leaves. Each gall is regularly cylindrical, a bit swollen below the tip, a bit restricted basally, up to 5.0 mm in length and 2.5 mm in diameter. The exterior of the gall fairly smooth, entirely naked except for a blue or purplish scurf. The body of gall hollow, open at top, the open cavity penetrating to a third or a half of the gall, separated from the larval cell by a thin partition; larval cell floored with a thicker partition beneath which another cavity is to be found. Young galls straw and light rose pink, sometimes touched more purple red, the whole touched with an ashy-blue scurf; older galls becoming burnt red to purple brown or dark, dirty brown. Each gall separated, often occurring in great numbers and dense masses, usually on under surfaces, rarely on upper surfaces of leaves.

Biology. Only the asexual generation is known, inducing galls on Q. deserticola (= Q. texcocana) (section Quercus, subsection Leucomexicana). Galls mature in autumn; adults emerge from February to mid-March.

Distribution. Mexico: Mexico City, Puebla (Kinsey 1937).

Xystoteras cylindratum, n. sp.
Agamic form

Gall. —- Small, naked, hollow cylinders scattered on the under surfaces of leaves. Each gall rather regularly cylindrical, a bit swollen below the tip. a bit restricted basally, up to 5.0 mm. in length and 2.5 mm. in diameter, averaging nearer 3.5 mm. in length and 1.7 mm. in diameter. Exterior of gall fairly smooth, entirely naked except for a blue or purplish scurf. Body of gall hollow, open at top, the open cavity penetrating a third or a half of the gall, separated from the larval cell by a thin partition; larval cell floored with a thicker partition beneath which still another cavity is to be found. Young galls straw and light rose oink, sometimes touched more purple red, the whole touched with an ashy-blue scurf; older galls becoming burnt red to purple brown or dark, dirty brown. Each gall separate, but galls often occurring in great numbers and in dense masses, usually on under surfaces, rarely on upper surfaces of leaves of oak,

Host. — Quereus texcocana. [deserticola]

Range. — Mexico: Mexico City, 22 E, 8200\ and 25 E, 7000\ — Puebla: El Seco, 5 SW, S200\ — Apparently extending from the Valle}' of Mexico southeastwardly toward Vera Cruz.

Life History. —- Adults: December 5, 16, 23. January 9. March 10, 15. April 1, 10. Most of the emergence in the middle of March.

This species is very abundant on the oaks directly east of Mexico City. Both in 1931-32 and in 1935-36 we found the insects so abundant that quarts of the tiny galls might have been gathered from small stands of trees — except for the difficulty of picking up such small objects after they had once fallen to the ground. At the present stage of our studies, I do not recognize what are the closest relatives of the species.