Pheidole corniclypeus

This species occurs in lowland rainforest. Minor and occasionally major workers recruit to ground baits, and minor workers occur in Winkler samples of sifted litter and rotten wood.

Identification
Minor: face and mesosoma foveolate, with foveolation absent on anteroventral portion of katepisternum; promesonotal groove absent; propodeal spines one fourth to one third length of posterior face of propodeum; gaster smooth and shining; abundant erect setae on mesosomal dorsum and gaster; tibiae with 3-4 erect setae; color orange.

Major: lateral clypeus with a prominent blunt tooth, porrect, anterolateral to termination of frontal carina and contiguous with anterior border of antennal fossa, in profile view as long as flared anterolateral margin of frontal carina, and the gap between the two forming a deep V-shaped notch; inner hypostomal teeth distinct, closely spaced; scape base terete; face with distinct scrobes, delimited dorsally by frontal carinae and forming concave trough below them, ventral and posterior margins less delimited, surface of scrobe smooth and shiny; head moderately depressed posteriorly; face surface generally shiny, overlain with subparallel carinae, these longitudinal anteriorly, divergent and oblique on vertex lobes; propodeal spines one third length of posterior face of propodeum; gastral dorsum smooth and shining; sides of head with abundant erect setae; abundant erect setae on mesosomal dorsum, tibiae, and gaster.

Measurements, minor worker: HW 0.45, HL 0.48, SL 0.45, EL 0.10, WL 0.58, PSL 0.04, PTW 0.08, PPW 0.13, CI 93, SI 99, PSLI 8, PPI 166 (n=6).

Measurements, major worker: HW 0.98, HL 1.18, SL 0.43, EL 0.14, WL 0.89, PSL 0.07, PTW 0.19, PPW 0.35, CI 83, SI 44, PSLI 7, PPI 187 (n=5).

This species is primarily known from a few collections from Cerro Musún in central Nicaragua. The major workers are easily identifiable by the unique clypeal teeth. Minor workers are very difficult to separate from other P. flavens-like species when in mixed samples, and from other members of the species complex in general. The sympatric Pheidole natalie has the katepisternum completely foveolate. Pheidole corniclypeus and the parapatric Pheidole costaricensis have the anterolateral katepisternum smooth and shiny, and at present they appear indistinguishable. DNA barcodes cluster a specimen from the La Moskitia region of Honduras, several specimens from Musún, and a specimen from the Cordillera de Guanacaste in northwest Costa Rica (Cerro Cacao at 740 m). The BOLD image of the Guanacaste specimen is a minor worker and is consistent with being a member of this species complex. See additional comments under Pheidole andersoni.

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

Nomenclature

 *  corniclypeus. Pheidole corniclypeus Longino, 2019: 30, fig. 13 (w.) NICARAGUA.

Type Material

 * HOLOTYPE: 1 major worker, Nicaragua, Matagalpa: RN Cerro Musún, 12.96002 -85.23219 ±60 m, 730 m, 3-May-2011, tropical wet forest, at bait (LLAMA, Ba-D-01-1-03-04) [MCZC, unique specimen identifier CASENT0623849].
 * PARATYPES: major, minor workers: same data as holotype [CAS, DZUP, MCZC, USNM]; same data except 12.95944 -85.22526 ±100 m, 680 m (Ba-D-01-2-04-12) [JTLC].

Etymology
Referring to the spines projecting from the clypeus.