Pheidole cerebrosior Wheeler

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 569

Pheidole cerebrosior Wheeler

Pheidole vinelandica subsp. cerebrosior Wheeler 1915b: 405. Raised to species level by Creighton 1950a: 175.

types Amer. Mus. Nat. Hist.; Mus. Comp. Zool. Harvard.

Etymology Unknown.

Diagnosis A member of the " bicarinata complex" of the larger pilifera group; for a characterization of the complex, see under bicarinata .

P. cerebrosior is distinguished within the complex by the following combination of traits.

Major: postpetiole seen from above very wide and conulate; propodeal spines well-developed and backward-directed; pronotal humeri with short irregular carinulae.

Minor: mesosoma! pilosity comprises rows of evenly spaced pairs of erect hairs. Measurements (mm) Lectotype major: HW 1.12, HL 1.32, SL 0.60, EL 0.14, PW 0.58. Paralectotype minor: HW 0.46, HL 0.56, SL 0.44, EL 0.12, PW 0.28.

Color Major: body light reddish yellow, except for the gaster, which is a slightly contrasting yellowish brown. Minor: concolorous plain yellow.

Range Arizona and New Mexico, 550 to 1680 m; southern California, 950 m; Baja California, 640 m; Chihuahua, 1500 m (Creighton and Gregg 1955); numerous records by Stefan Cover (collection notes) and extreme southern Nevada (G. C. and J. Wheeler 1986g).

biology Creighton and Gregg (1955) report that the preferred habitat of cerebrosior is evergreen-oak-woodland in mountain canyons, with open desert less frequently occupied. The colonies are always small, and contain no more than 3 or 4 majors. Stefan Cover (unpublished specimen data) found numerous colonies in open Ephedra, mesquite, and mesquite-acacia desert, as well as riverine cottonwood forest, nesting variously under rocks beneath cow dung, and in open soil with multiple small crater nests. He found seed chambers in some nests and observed workers feeding on a dead beetle. A winged queen has been collected on 1 July. In Nevada, G. C. and Jeanette N. Wheeler (1986g) found a single colony under a half-buried stone in yucca-larrea desert.

Figure Upper: lectotype, major. Lower: paralectotype, minor. ARIZONA: Tucson. Scale bars = 1 mm.