Pheidole kasparii

This species occurs in cloud forest to high montane oak forest. It is locally abundant around the type locality. Minor and major workers recruit to ground baits, and workers occur in Winkler samples of sifted litter and rotten wood. Nests have been found under epiphytes on recent branch falls, under epiphytes on clay banks (road cut), in an acorn amongst ground litter, and in a cavity in a low, moss-covered live stem of Siparuna.

Identification
Minor: face smooth and shining; vertex margin shallowly emarginate in full face view; promesonotal groove absent; pronotum entirely smooth and shiny; katepisternum shiny, with varying development of faint foveolation; propodeal spines in form of obtuse to right angles, not spiniform; gaster smooth and shining; abundant erect setae on mesosomal and gastral dorsum; tibiae lack erect setae; color red brown to yellow (color variation can be intracolonial).

Major: median hypostomal tooth strongly developed; inner hypostomal teeth very weakly developed, hardly visible, closer to outer hypostomal teeth than to medial tooth, recessed, not on ventral margin of hypostomal bridge; ventral margin of head in profile view convex; scape base terete; face mostly smooth and shiny, with longitudinal carinulae between eye and antennal fossa; propodeal spines in form of short, triangular teeth, < one fifth length of posterior face of propodeum; gastral dorsum smooth and shiny; abundant erect setae on sides of head, mesosomal and gastral dorsum; tibiae lack erect setae.

Measurements, minor worker: HW 0.41, HL 0.43, SL 0.34, EL 0.10, WL 0.47, PSL 0.01, PTW 0.07, PPW 0.09, CI 96, SI 85, PSLI 2, PPI 129 (n=2).

Measurements, major worker: HW 0.79, HL 0.87, SL 0.40, EL 0.12, WL 0.68, PSL 0.02, PTW 0.12, PPW 0.16, CI 91, SI 50, PSLI 3, PPI 133 (n=2).

Measurements, queen: HW 0.87, HL 0.81, SL 0.48, EL 0.26, WL 1.39, PSL 0.00, PTW 0.27, PPW 0.38, CI 108, SL 55, PSLI 0, PPI 139.

A complex of very similar species occurs in wet forests of Costa Rica: Pheidole kasparii, Pheidole nitella, and Pheidole sagittaria. Pheidole kasparii as currently understood is a narrow endemic, known only from the vicinity of the type locality, and allopatric to the other two. Pheidole nitella and P. sagittaria occur on the Atlantic slope of Costa Rica, where they are sympatric.

The minor workers of the complex are not readily distinguishable, sharing the habitus of being very small, almost completely smooth and shining, and with very short propodeal spines that are no more than low angles in profile. The major workers are more distinct. The inner hypostomal teeth of P. kasparii are farther apart and smaller than the teeth of P. nitella and P. sagittaria, and recessed behind the ventral margin of the hypostomal bridge. Pheidole sagittaria has the ventral margin of the head in profile very flat, while on P. kasparii and P. nitella it is more convex. The head of P. nitella is relatively more narrow than the heads of P. kasparii and P. sagittaria (CI ~84 vs. 90-95).

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

Nomenclature

 *  kasparii. Pheidole kasparii Longino, 2019: 40, fig. 5 (w.q.) COSTA RICA.

Type Material

 * HOLOTYPE: 1 major worker, Costa Rica, San José: 8km S Santa Maria, 9.57666 -83.94911 ±20 m, 1700 m, 25-Jun-2015, cloud forest, under epiphytes (J. Longino, JTL9356) [MUCR, unique specimen identifier CASENT0637174].
 * PARATYPES: major, minor worker, dealate queen: same data as holotype [MUCR]; same data except 9.56895 -83.94756 ±20 m, 1770 m, 25-Jun-2015, cloud forest, nest under epiphytes (J. Longino, JTL9358) [CAS, DZUP, JTLC, MCZC, USNM].

Etymology
In honor of ant ecologist extraordinaire, Mike Kaspari.