Pheidole yucatana ^HNS new species

Types Mus. Comp. Zool. Harvard.

Etymology L yucatana ^HNS, from the Mexican region of the type locality.

diagnosis A member of the " bicarinata ^HNS complex" of the larger pilifera ^HNS group, comprising agricola ^HNS, aurea ^HNS, barbata ^HNS, bicarinata ^HNS, centeotl ^HNS, cerebrosior ^HNS, defecta ^HNS, gilvescens ^HNS, macclendoni ^HNS, macrops ^HNS, marcidula ^HNS, paiute ^HNS, pinealis ^HNS, xerophila ^HNS, yaqui ^HNS, and yucatana ^HNS, which complex is characterized by the large to very large, forward-set eyes in both castes; and, in the major, the occipital lobes lacking any sculpturing (except in aurea ^HNS); the posterior half of the head capsule almost entirely smooth and shiny; and the postpetiolar node seen from above oval, elliptical, or laterally subangular (cornulate in cerebrosior ^HNS). P. yucatana ^HNS is distinguished by the following combination of traits.

Major: in side view, promesonotal juncture subangulate; propodeal spines reduced to right angles; occiput sprinkled with sparse but coarse foveae; faint carinulae extend from behind eye to occipital corners; postpetiolar node from above laterally subangulate. Minor: in side view propodeal spines reduced to right angles.

measurements (mm) Holotype major: HW 1.04, HL 1.20, SL 0.58, EL 0.10, PW 0.48.

Paratype minor: HW 0.52, HL 0.60, SL 0.54, EL 0.14, PW 0.32.

Color Major: body medium reddish brown, appendages light reddish brown.

Minor: body light plain brown, tarsi and tibiae yellow, rest of appendages brownish yellow.

Range Known only from the type locality.

Biology From a nest in dry soil at roadside. A winged queen was present in the nest on 25 July.

figure Upper: holotype, major. Lower: paratype, minor. MEXICO: 11 km south of Progreso (E. O. Wilson). Scale bars = 1 mm.