Pheidole exarata

Longino, J. T., 2009, Additions to the taxonomy of New World Pheidole (Hymenoptera: Formicidae)., Zootaxa 2181, pp. 1-90 : 31

Pheidole exarata

Pheidole exarata Emery, 1896: 68 . Syntype major, minor worker: Costa Rica, San Jose: San Jose [ MCSN] (not examined). See also: Wilson, 2003: 686.

Pheidole crassipes r. grantae Forel, 1908: 53 . Syntype major, minor worker: Costa Rica, Cartago: Cote Tablazo [a montane site near Cartago] (Biolley) [ MHNG] (examined). Wilson, 2003: 700: raised to species. New synonymy.

Geographic Range

Venezuela, Colombia, Costa Rica.

Biology

Pheidole exarata occurs in mature wet forest habitats from 800-1600m elevation. It is arboreal, forming large colonies beneath epiphytes and in live stems. An incipient colony was found in a cavity in a live, 1.5cm diameter stem of a melastomataceous vine; a colony was found in several internodes of a Cecropia insignis sapling, another in an internode of Cecropia angustifolia; a large aggregation of minor and major workers, but no sexuals or brood, was found in a clean hollow stem of Neomirandea angularis (Asteraceae). One colony under epiphytes was observed with multiple dealate queens, evidence of polygyny.

Comments

The types of P. grantae closely match the drawings of P. exarata in Wilson (2003), the type localities are relatively close, and there is no evidence of distinct sympatric forms of this moderately common species in the central highlands of Costa Rica. Pheidole exarata is an upland version of the closely related lowland species, P. excubitor Wilson. A third member of this complex is P. stulta Forel (the oldest name in the complex). Pheidole stulta is similar to P. exubitor but with less sculpture on the face of the major and pronotum of the minor ( Wilson 2003). Geographic variation is not well understood in these forms and the distinctness of P. exarata, P. exubitor and P. stulta should be further evaluated.