Pheidole polymorpha, Wilson, E. O., 2003

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 592

Pheidole polymorpha new species

Types Mus. Comp. Zool. Harvard.

etymology Gr polymorpha , many forms, referring to the coexistence of major and supermajor castes.

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

P. polymorpha is distinguished within the complex by the following combination of traits. Worker caste trimorphic, with major, supermajor, and minor.

Major: humerus very pronounced and subtriangular in shape in dorsal-oblique view; propodeal spines stout and vertical to the basal propodeal face; postpetiole from above with sharp right-angular margins; pilosity, long and dense.

Minor: all of mesosoma and almost all of the dorsal head surface foveolate and opaque. Both major and minor: dorsal margin of petiole seen from behind strongly convex.

Measurements (mm) Holotype major: HW 1.34, HL 1.46, SL 0.62, EL 0.20, PW 0.60.

Paratype minor: HW 0.54, HL 0.60, SL 0.56, EL 0.14, PW 0.38.

color Major and minor: brownish yellow.

Range Known only from the type locality and from Chapulco, Puebla, Mexico.

Biology Collected in upland desert. Comment by Stefan Cover (personal communication): "A very interesting beast; it is like P. artemisia or P. cavigenis on steroids."

Figure Upper: holotype, major; partial head in full-face view of paratype, supermajor. Lower: paratype, minor. MEXICO: Highway 57, km 127, Estado Mexico (Cornell University Field Party, 1965). Scale bars = 1 mm.