Pheidole torosa ^HNS new species

Types Mus. Comp. Zool. Harvard.

Etymology L torosa ^HNS, muscular, bulging, a reference to the major caste.

diagnosis A member of the " pilifera ^HNS complex" of the larger pilifera ^HNS group, comprising calens ^HNS, californica ^HNS, carrolli ^HNS, cavigenis ^HNS, clementensis ^HNS, creightoni ^HNS, hoplitica ^HNS, littoralis ^HNS, micula ^HNS, pilifera ^HNS, polymorpha ^HNS, rugulosa ^HNS, senex ^HNS, soritis ^HNS, tepicana ^HNS, and torosa ^HNS, which complex is distinguished by the following traits. Major: dorsal head surface extensively sculptured; occipital lobe transversely rugulose (or, in carrolli ^HNS smooth, in littoralis ^HNS foveate, and in micula ^HNS and soritis ^HNS carinulate); postpetiole from above diamond-shaped, trapezoidal, or spinose. Minor: eye medium-sized to large. P. torosa ^HNS is distinguished within the complex as follows.

Major: bicolorous; transverse rugulae cover posterior fifth of dorsal surface of head in full-face view, and longitudinal carinulae cover all of the remainder of the dorsal surface except the frontal triangle; humerus in dorsal-oblique view prominent and lobose; in side view, mesonotum drops almost vertically to metanotum; propodeal spines very long, stout, and vertical to propodeal basal face; seen from above, postpetiole very wide relative to petiole, and spinose.

Minor: all of head and mesosoma foveolate and opaque; pilosity along promesonotal dorsum consists of evenly spaced pairs of setae.

This species is very close to and possibly synonymous with senex ^HNS.

Measurements (mm) Holotype major: HW 1.56, HL 1.84, SL 0.76, EL 0.20, PW 0.68.

Paratype minor: HW 0.58, HL 0.64, SL 0.62, EL 0.14, PW 0.32.

color Major: bicolorous, with light reddish brown head and appendages contrasting with dark brown mesosoma and gaster.

Minor: concolorous light brown.

Range Known only from the type locality.

Biology Unknown.

Figure Upper: holotype, major. Lower: paratype, minor. MEXICO: El Sueco, Chihuahua. Scale bars = 1 mm.