Pheidole lineafrons

This species occurs in cloud forest. It is known from one collection. Nocturnal foragers recruited to a bait at the foot of a 4-month old landslide in mature forest. The landslide formed a steep bare soil face about 10 m across and 20 m tall. Minor workers recruited from a nest entrance about 2 m away in the bank. The entrance was an irregular hole, with no infrastructure. Major workers were gathered near and just inside the entrance.

Identification
Minor: face shiny, with faint foveolation on anterior half, arcuate carinulae between eye and frontal carinae, subparallel transverse carinulae on posterior half; head tapering posteriorly to thin occipital carina; promesonotal groove very weakly impressed; pronotal dorsum transversely carinulate; lateral pronotum very weakly foveolate peripherally, smooth and shiny medially; katepisternum foveolate; propodeal spines in form of low angles, not spiniform; first gastral tergite smooth and shining; abundant flexuous erect setae on mesosomal and gastral dorsum; tibia lacking erect setae; color orange.

Major: inner hypostomal teeth pronounced, closely spaced; scape base terete; face with faint foveolation overlain with subparallel longitudinal rugulae medial to eye, arcuate rugulae in antennal fossa, faint longitudinal carinulae on frons between frontal carinae, weak short transverse carinulae on posteriormost vertex lobes, rest of face smooth and shiny; propodeal spines short, < one fifth length of posterior face of propodeum; first gastral tergite smooth and shiny; sides of head with abundant erect setae; mesosomal and gastral dorsum with abundant erect setae; tibia with erect setae.

Measurements, minor worker: HW 0.70, HL 0.87, SL 1.10, EL 0.15, WL 1.20, PSL 0.02, PTW 0.15, PPW 0.21, CI 80, SI 157, PSLI 2, PPI 139 (n=1).

Measurements, major worker: HW 1.57, HL 1.63, SL 1.29, EL 0.24, WL 1.54, PSL 0.05, PTW 0.25, PPW 0.40, CI 96, SI 82, PSLI 3, PPI 157 (n=1).

This is a highly distinctive species. The face of the minor worker has fine arcuate carinulae similar to other cloud forest species Pheidole innupta and Pheidole alfaroi. Compared to P. innupta the minor worker is orange (dark brown in P. innupta), has longer scapes (mean SI 157 vs. 136), and the head is more tapering posteriorly. Comared to P. alfaroi the minor worker is larger (mean HW 0.70 vs. 0.60) and the head is more tapering.

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

Minor
Images from AntWeb

Nomenclature

 *  . Pheidole  Longino, 2019: 43, fig. 54 (w.) COSTA RICA.

Type Material

 * HOLOTYPE: 1 major worker, Costa Rica, Puntarenas: Monteverde, 10.31125 -84.80465 ±20 m, 1480 m, 27-Mar-2018, cloud forest, nest in clay bank (J. Longino, JTL10137) [MUCR, unique specimen identifier CASENT0644875].
 * PARATYPES: major, minor workers: same data as holotype [CAS, MCZC, MUCR, USNM].

Etymology
In reference to the transverse striations on the face of the minor worker.

References based on Global Ant Biodiversity Informatics

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