Pheidole polymorpha HNS new species
Types Mus. Comp. Zool. Harvard.
etymology Gr polymorpha HNS, many forms, referring to the coexistence of major and supermajor castes.
diagnosis a member of the " pilifera HNS complex" of the larger pilifera HNS group, comprising calens HNS, californica HNS, carrolli HNS, cavifrons 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 lobes 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. polymorpha HNS 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 HNS or P. cavigenis HNS 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.