Cynips (plumbea) subfusca, new species
agamic form

GALL.—Practically identical with galls of C. plumbea. Large, hemi spherical, with a broadly flattened base; surface smooth and shining, not shriveling; bluish gray scurf easily wiped off, exposing the tan brown color of older galls; up to 11.0 mm. in diameter. Figures 105, 108.

HOST.-Quercus sacame, an oak closely related to Q. arizonica.

RANGE.-Chihuahua: Pacheco, 20 E, 5400'. San Buenaventura, 3 E, 5600'. Occurring on the eastern side of the Western Sierra of Mexico, prob ably restricted to Chihuahua (and northernmost Durango?). Figure 102.

LIFE HISTORY..—Adults: January 20. February 6, 15.

The galls of subfusca are practically identical with the galls of plumbea. The insects of subfusca differ only in being richer and darker brown and in averaging rather smaller; but these differences are so evident to the naked eye, and so constant in a series of 40 individuals of subfusca, that it seems evident that here is a population with a distinct genetic make-up. Although lack of adequate maps and records of explorations makes our knowledge of the topography and flora of Northern Chihuahua uncertain, we ourselves were unable to find oak in that state north of a point lying between Casas Grandes and Pacheco. This leaves something like 100 miles of oak-free mountains and very arid deserts isolating subfusca from plumbea.

The insects of subfusca are also close to those of C. euconus, from Southern Durango; but euconus galls are conical with circular bases.

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