Pheidole probolonotum

This species occurs in lowland rainforest. Workers recruit to ground baits and occur in Winkler samples of sifted litter and rotten wood. A nest was discovered in a vertical clay bank in forest. The entrance was an irregular opening, leading to shallow chambers. So far this species is known only from Los Tuxtlas Biological Station.

Identification
Minor: face partially smooth and shining, with discrete patches of faint foveolation scattered over surface; head weakly emarginate behind; promesonotal groove strongly impressed, mesonotum strongly produced, angulate; pronotum smooth and shiny; katepisternum foveolate; propodeal spines about two thirds length of posterior face of propodeum; gaster smooth and shining; pronotum with 0-2 pairs short stiff erect setae; tibiae lack erect setae; gaster with very sparse, fully appressed short pubescence, 0-few longer erect setae; color dark brown.

Major: inner hypostomal teeth widely spaced, acicular; scape base terete; face foveolate throughout, overlain with reticulate rugulae; mesonotum strongly produced; propodeal spines about two thirds length of posterior face of propodeum; gastral dorsum smooth and shiny; pilosity pattern similar to worker, with dorsal surfaces nearly devoid of erect setae.

Measurements, minor worker: HW 0.60, HL 0.67, SL 0.79, EL 0.16, WL 0.88, PSL 0.10, PTW 0.14, PPW 0.21, CI 91, SI 130, PSLI 16, PPI 148 (n=1).

Measurements, major worker: HW 0.93, HL 0.99, SL 0.73, EL 0.18, WL 0.95, PSL 0.12, PTW 0.21, PPW 0.33, CI 94, SI 78, PSLI 13, PPI 154 (n=1).

This species is a version of Pheidole plebecula. Pheidole plebecula is highly geographically variable and P. probolonotum is within the global range of variation of P. plebecula. However, it is sympatric with a regional form of P. plebecula. Compared to the regional form, the dorsal pilosity is reduced and the face of the minor worker has a mix of smooth and foveolate sculpture (smooth in the regional form of P. plebecula).

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Nomenclature

 *  probolonotum. Pheidole probolonotum Longino, 2019: 54, fig. 41 (w.) MEXICO.

Type Material

 * HOLOTYPE: 1 major worker, Mexico, Veracruz: Estación de Biología Los Tuxtlas, 18.58461 -95.07375 ±20 m, 150 m, 31-May-2016, mature wet forest, nest in clay bank (J. Longino, JTL9560) [UNAM, unique specimen identifier CASENT0631751].
 * PARATYPES: major, minor workers: same data as holotype [CAS, DZUP, JTLC, MCZC, UNAM, USNM].

Etymology
In reference to the strongly projecting mesonotum.

References based on Global Ant Biodiversity Informatics

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