Pheidole cavigenis Wheeler, 2003

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 567

Pheidole cavigenis Wheeler , new status

Pheidole tepicana subsp. cavigenis Wheeler 1915b: 403.

Types Mus. Comp. Zool. Harvard.

Etymology L cavigenis , hollow cheek, significance unknown.

Diagnosis A member of the " pilifera complex" of the larger pilifera group; for a characterization of the complex, see under pilifera . P. cavigenis is distinguished within the complex by the following combination of traits.

Major: occiput and extensive dorsal surface anterior to the occiput rugoreticulate; a small patch of rugoreticulum is present just posterior to each antennal fossa; humerus very prominent and lobose in dorsal-oblique view; mesonotal convexity absent, but mesonotum descends abruptly to the metanotal groove; propodeal spines long and thin; postpetiole spinose. Minor: almost all of dorsal head surface longitudinally carinulate; propodeal spine needle-shaped. Measurements (mm) Major (Montezuma Pass, Arizona): HW 1.60, HL 1.86, SL 0.74, EL 0.22, PW 0.76. Minor: HW 0.62, HL 0.66, SL 0.62, EL 0.12, PW 0.40.

Color Major: body light reddish brown, mandibles and gaster plain medium brown. Minor: head and gaster medium brown, mesosoma and appendages light brown.

Range Known from several collections in the Huachuca Mts; thence west to Sycamore Canyon in the Pajarito Mts., about 20 miles west of Nogales (Stefan Cover). A series in the Museum of Comparative Zoology from Bocoyna, Chihuahua, belongs to this species but with some differences; it may represent a geographical variant.

biology According to Stefan Cover, who has collected intensively within the range of cavigenis , this species occurs in grassy gaps in juniper-oak-pinyon woodlands at mid-elevations. Nests are cryptic and seeds are sometimes found inside. Colonies appear to consist of no more than 200-300 individuals.

Figure Upper: major. Lower: minor. ARIZONA: 11 km west-northwest of Montezuma Pass, Huachuca Mts., Cochise Co., 1660 m (Stefan Cover). Scale bars = 1 mm.