Cynips (plumbea) glabrescens, new species
agamic form

GALL.-Large, subspherical, with a broadly flattened or somewhat con cave base; dull; shallowly but very distinctly shriveling; with some lead gray scurf; older gall rather dark brown or reddish brown in color; up to 9.0 mm. in diameter. Often indistinguishable from galls of C. (arida) saxw lum which occur in parts of the same area. Figure 118.

HOSTS.–Quercus undata, Q. chihuahuensis, Q. sacame [arizonica], Q. reticulata [rugosa]; and possibly on the dwarf oak Q. depressipes.

RANGE.-Chihuahua: Santa ſsabel, 6 E, 6000' (gall; Q. umdata). Durango: Durango, 2 N, 6500' (Q. undata, types). Canatlán, 7 N, 7400' (Q. undata). Patos, 15 W, 8000' (Q. sacame, Q. chihuahuensis). Otinapa, 8500' (Q. sacame, Q. reticulata; galls on Q. depressipes 2). Probably restricted to a portion of the Western Sierra of Mexico, in southernmost Chihuahua, and in Durango. Figure 102.

LIFE HISTORY..—Mature larvae: November 8–14. Adults: November 19. February 5, 10, 15, 18, 20, 22, 25, 28, 29. March 2, 4, 8, 11, 22. Most of the emergence late in February, early in March.

This insect is closer in general appearance to plumbea than it is to subfusca, its immediate neighbor to the north. It differs from plumbea in several details, and in the interesting character of having hairs only on the second abdominal segment. The gall of glabrescens is obviously dull and shriveled on the surface, distinctly different from the smooth and shining galls of plumbea and subfusca.

We are under the impression that the mountains of Central Durango are so separated from the rest of the Sierras that the oaks do not range continuously from there into the northern part of the state. We found it impossible to travel the mountain roads between Indé and Santiago Papasquiaro, so we cannot fix the northern boundary of the range of glabrescens. To the south, from Zacatecas through Jalisco, glabrescens is replaced by C. jalisco.

- Alfred Kinsey: (1936) Origin of higher categories in Cynips^©