Pheidole pinealis

The type colony was found beneath a stone; the nest contained seed caches (Wheeler 1908). In western Texas, Moody and Francke (1982) found three colonies, variously at 1000–1200 m, nesting, respectively, beneath a stone and cow dung and in open soil. (Wilson 2003)

Identification
See the description in the nomenclature section.

Distribution
Known only from western Texas and a series from Guanajuato, central Mexico. (Wilson 2003)

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Biology
The colonies taken in Coahuila were under stones, and no store of seeds was found. It may be recalled that the type nest of pineaJis contained many seeds. Their absence in the three colonies cited above may be due to the fact that these nests were excavated in February, a month when there is seldom much foraging activity in harvesting species.The colonies of pinealis appear to be small. The nest taken in the Sierra de la Muralla consisted of fifteen majors and thirty-three minors. Those taken near Arteaga consisted of eight majors and twenty-four minors in one nest and twenty-one majors and thirty-six minors in the other. (Creighton and Gregg 1959)

Worker
Minor

Nomenclature

 *  pinealis. Pheidole pinealis Wheeler, W.M. 1908e: 459, pl. 27, fig. 38 (s.w.) U.S.A. See also: Wilson, 2003: 591.

Description
From Wilson (2003): DIAGNOSIS A member of the “bicarinata complex” of the larger pilifera group, comprising Pheidole agricola, Pheidole aurea, Pheidole barbata, Pheidole bicarinata, Pheidole centeotl, Pheidole cerebrosior, Pheidole ceres,Pheidole defecta, Pheidole gilvescens, Pheidole macclendoni, Pheidole macrops, Pheidole marcidula, Pheidole paiute, Pheidole pinealis, Pheidole xerophila, Pheidole yaqui and Pheidole yucatana, which complex is characterized by the large to very large, forward-set eyes, especially in the minor; and in the major, the occipital lobes lacking any sculpturing (except in aurea); the posterior half of the head capsule smooth and shiny; and the postpetiole seen from above oval, elliptical, or laterally angulate (cornulate in cerebrosior).

P. pinealis differs within the complex by the following combination of traits.

Major: dark spot on vertex; humerus in dorsal-oblique view right-angulate; petiole in side view tapers to a point, and from behind is deeply concave; postpetiolar lateral extension from above horn-shaped; erect pilosity of pronotum long and dense.

Minor: humerus in dorsal-oblique view feebly subangulate; postpetiole from above roughly diamond-shaped.

MEASUREMENTS (mm) Lectotype major: HW 1.06, HL 1.24, SL 0.52, EL 0.14, PW 0.54. Paralectotype minor: HW 0.48, HL 0.54, SL 0.46, EL 0.10, PW 0.30.

COLOR Major: head and mesosoma light brown with a slightly reddish tinge; center of head dorsum with contrasting circular dark brown spot, as illustrated; waist and gaster dark brown; appendages brownish yellow.

Minor: concolorous medium brown (brownish yellow, possibly faded, in paralectotype); appendages yellowish brown.



'''Figure. Upper: lectotype, major. Lower: paralectotype, minor. Scale bars = 1 mm.'''

Type Material
TEXAS: Limpio Canyon, Ft. Davis, Davis Mts., Jeff Davis Co., southwestern Texas, col. W. M. Wheeler. and - as reported in Wilson (2003)

Etymology
Unknown

References based on Global Ant Biodiversity Informatics

 * LeBrun E. G., R. M. Plowes, and L. E. Gilbert. 2015. Imported fire ants near the edge of their range: disturbance and moisture determine prevalence and impact of an invasive social insect. Journal of Animal Ecology,81: 884–895.
 * Moody J. V., and O. F. Francke. 1982. The Ants (Hymenoptera, Formicidae) of Western Texas Part 1: Subfamily Myrmicinae. Graduate Studies Texas Tech University 27: 80 pp.
 * O'Keefe S. T., J. L. Cook, T. Dudek, D. F. Wunneburger, M. D. Guzman, R. N. Coulson, and S. B. Vinson. 2000. The Distribution of Texas Ants. The Southwestern Entomologist 22: 1-92.
 * Wheeler, G.C. and J. Wheeler. 1985. A checklist of Texas ants. Prairie Naturalist 17:49-64.
 * Wilson, E.O. 2003. Pheidole in the New World: A Dominant, Hyperdiverse Genus. Harvard University Press