Pheidole carinitida

This species inhabits montane wet forest. Minor and major workers recruit to ground baits and are collected in Winkler samples of sifted leaf litter and rotten wood from the forest floor.

Identification
Minor: face foveolate, overlain with faint reticulate rugulae to variable extent; vertex margin weakly emarginate in face view; frontal carinae expanded and elevated anterolaterally, forming short teeth that project over clypeus; promesonotal groove absent; dorsal pronotum foveolate, overlain with reticulate rugulae; lateral pronotum and katepisternum foveolate; propodeal spines about two thirds length of posterior face of propodeum; gaster smooth and shining; abundant erect setae on mesosomal dorsum and gaster; tibiae without erect setae; color dark brown.

Major: inner hypostomal teeth stout, closely spaced; scape base terete; face foveolate overlain with longitudinal carinulae on anterior portion of face, fading to smooth and shiny on vertex lobes; propodeal spines one third to one half length of posterior face of propodeum; gastral dorsum smooth and shining; sides of head with abundant erect setae; abundant flexuous erect setae on mesosomal dorsum and gaster; tibiae without erect setae.

Measurements, minor worker: HW 0.50, HL 0.52, SL 0.46, EL 0.10, WL 0.60, PSL 0.07, PTW 0.08, PPW 0.14, CI 96, SI 92, PSLI 14, PPI 170 (n=2).

Measurements, major worker: HW 1.05, HL 1.11, SL 0.52, EL 0.14, WL 0.83, PSL 0.09, PTW 0.17, PPW 0.34, CI 95, SI 50, PSLI 9, PPI 203 (n=2).

This species appears to be a montane version of the lowland species Pheidole carinote, both species known only from the Pacific slope of Costa Rica. Pheidole carinitida differs in the major having a largely smooth and shiny face, and the minor worker tibia lacks erect setae.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica.

Nomenclature

 *  carinitida. Pheidole carinitida Longino, 2019: 30, fig. 23 (w.) COSTA RICA.

Type Material

 * HOLOTYPE: 1 major worker, Costa Rica, San José: Cerro Plano, 9.48141 -83.96276 ±100 m, 1070 m, 6-Jul-2015, ridgetop cloud forest, at bait (ADMAC, Ba-E-06-1-05-11) [MUCR, unique specimen identifier CASENT0631620].
 * PARATYPES: major, minor workers: same data as holotype [MCZC, MUCR]; same data except 9.48264 -83.96264 ±10 m, 1070 m, 4-Jul-2015, ex sifted leaf litter (ADMAC, Wa-E-06-2-24) [CAS]; 9.48297 -83.96211 ±10 m, 1060 m (Wa-E-06-2-40) [DZUP, USNM].

Etymology
Similar to P. carinote, but with shinier major worker.

References based on Global Ant Biodiversity Informatics

 * Longino J. T. 2019. Pheidole (Hymenoptera, Formicidae) of Middle American wet forest. Zootaxa 4599: 1-126