Pheidole rhinomontana

This species inhabits mature montane wet forest habitats, from 500-1600m elevation. Workers are frequently visitors at baits on the ground and are common in Winkler samples of sifted leaf litter. Nests are in or under dead wood on the ground, often in shallow chambers near the surface or under loose bark. Incipient colonies with single queens are often encountered, and colonies can become quite populous. (Longino 2009)

Identification
With the habitus and morphometric profile of Pheidole rhinoceros. Minor worker: katepisternum largely foveolate versus smooth and shining (rhinoceros). Major worker: basal one third to one half of mandible coarsely striate versus largely smooth and shining; clypeus usually with longitudinal to oblique rugulae lateral to medial horn versus clypeus completely smooth and shining lateral to medial horn (rhinoceros). (Longino 2009)

Distribution
Costa Rica, Panama.

This taxon was described from Costa Rica.

Nomenclature

 *  rhinomontana. Pheidole rhinomontana Longino, 2009: 71, fig. 20 (s.w.) COSTA RICA.

Worker
Minor Measurements (paratype): HL 0.60, HW 0.56, HLA 0.21, SL 0.55, EL 0.11, ML 0.77, PSL 0.03, PMG 0.00, SPL 0.03, PTW 0.08, PPW 0.14, CI 94, SI 97, PSLI 5, PMGI 0, SPLI 5, PPI 175.

Measurements (n=9): HL 0.54-0.65, HW 0.50-0.60, SL 0.50-0.59, CI 90-94, SI 97-105.

Mandible smooth and shining; clypeus smooth and shining with faint medial longitudinal carina; face largely smooth and shining with variable degree of concentric carinulae around antennal insertion and faint foveolate sculpture between frontal carinae and compound eye; margin of vertex rounded with slight median impression; occipital carina narrow, not or barely visible in full face view; scape with abundant erect setae, longest about as long as maximum width of scape; promesonotal groove absent; propodeal spines present; pronotum smooth and shiny dorsally and laterally, with foveolae on humerus and strip of foveolae and transverse carinulae anterodorsally; katepisternum largely to entirely foveolate; sides and dorsum of propodeum foveolate; abundant setae on promesonotal dorsum; dorsal (outer) margin of hind tibia with abundant suberect setae, longest about as long as maximum width of tibia; first gastral tergum smooth and shining; gastral dorsum with abundant erect setae; color red brown.

Major Measurements (holotype): HL 1.55, HW 1.32, HLA 0.40, SL 0.64, EL 0.17, ML 1.33, PSL 0.09, PMG 0.01, SPL 0.05, PTW 0.21, PPW 0.38, IHT 0.21, OHT 0.58, CI 85, SI 48, PSLI 6, PMGI 1, SPLI 3, PPI 180, HTI 35.

Measurements (n=10): HL 1.29-1.74, HW 1.12-1.44, SL 0.60-0.71, CI 83-87, SI 48-53.

Mandible with coarse longitudinal rugae on basal one third to one half, remaining surface smooth; medial clypeus forming a differentiated, somewhat concave surface, sharply delimited by strong oblique carinae extending from anterior apices of frontal carinae; clypeus obsolete or absent lateral to these carinae, not differentiated from coarsely rugose anterior head capsule; medial clypeus with a pronounced acute laminar horn; usually with several weak longitudinal to oblique carinulae on the clypeal surface lateral to horn; anterior clypeal margin flat to weakly emarginate; anterolateral head capsule with longitudinal rugae, grading to reticulate rugae over foveolae between antennal insertion and compound eye, grading to faint foveolate sculpture on scrobal area beneath scapes, grading to smooth and shining on vertex lobes; area between frontal carinae with longitudinal carinulae; head with abundant suberect setae projecting from sides of head in face view; scape smooth and shining, terete at base, with abundant erect setae about as long as maximum width of scape; hypostomal margin flat; median tooth absent; inner hypostomal teeth pointed, stout, closer to midline than to outer hypostomal teeth; promesonotal groove absent; propodeal spines present; mesosoma largely smooth and shining, with faint transverse etchings on pronotum, faint foveolate sculpture on dorsal face of propodeum; dorsal (outer) margin of hind tibia with abundant erect setae, these not quite as long as maximum width of tibia; pilosity abundant on mesosomal dorsum; postpetiolar dorsum smooth and shining, in dorsal view broader than long, weakly conulate; first gastral tergite smooth and shining, with abundant erect setae; color red brown.