Pheidole tepicana

In the Santa Cruz Mountains of Arizona, Stefan Cover (unpublished notes) found a colony of tepicana in an open area with opuntia and dwarf acacia surrounded by blue oak, nesting under a stone in the sun; the nest contained a cache of seeds. The species is notably flexible in its choices of nest site. Near Tucson, Arizona, I observed a colony in an open grassy area, spread out beneath multiple stones. In western Texas, Moody and Francke (1982) found numerous colonies, nesting mostly under stones and in open soil; one colony each was also beneath a log, a piece of metal, and a grass clump respectively. And finally, at Cuernavaca, Wheeler (1901b) observed that colonies were common beneath pats of half-dried cow dung. (Wilson 2003)

Identification
Pheidole tepicana has three worker castes: a minor, major and supermajor.

Mackay and Mackay (2002) - The deep, semicircular emargination (cut out margin) along the anterior border of the clypeus of the major, separates this species from all the others in New Mexico. The anterior 1/3 of the head is finely rugose, the posterior lateral lobes have fine, transverse striae, and the remainder of the head is smooth and glossy. The humeral angles are poorly developed, as are the lateral connules. The dorsum of the pronotum is smooth and glossy, much of the side of the mesosoma is glossy, and the propodeal spines are small and somewhat upturned. The minor worker is a small, brown specimen, with pale brown legs. The dorsum of the head is smooth and glossy, as is much of the mesosoma, especially the pronotum. The propodeal spines are small, consisting of tiny angles.

Also see the description in the nomenclature section.

Distribution
Texas, Arizona southward to at least Jalisco, Mexico: often locally abundant. (Wilson 2003)

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

Castes
Unusual in having three discrete worker castes.

The following images are provided by Harvard Museum of Comparative Zoology and Antweb.org

Worker
Minor

Additional images can be found on the Pheidole tepicana category page.

Nomenclature

 * carbonaria. Pheidole carbonaria Pergande, 1896: 881 (s.w.) MEXICO. Junior synonym of tepicana: Emery, 1901b: 119.
 * rugifrons. Pheidole rugifrons Pergande, 1896: 880 (s.) MEXICO. Junior synonym of tepicana: Emery, 1901b: 119.
 *  tepicana. Pheidole tepicana Pergande, 1896: 878 (s.w.) MEXICO. Taber & Cokendolpher, 1988: 95 (k.). Senior synonym of carbonaria, rugifrons: Emery, 1901b: 119; of instabilis, kingi (and its junior synonym townsendi), torpescens: Creighton & Gregg, 1955: 24. See also: Wilson, 2003: 601.
 * kingi. Pheidole kingi André, 1898: 244 (s.w.) MEXICO. Combination in P. (Allopheidole): Forel, 1912f: 237. Senior synonym of townsendi: Emery, 1922e: 105. Junior synonym of tepicana: Creighton & Gregg, 1955: 24.
 * townsendi. Pheidole townsendi André, 1898: 246 (s.w.) MEXICO. Junior synonym of kingi: Emery, 1922e: 105.
 * instabilis. Pheidole kingi subsp. instabilis Emery, 1901b: 120 (s.w.) U.S.A. Wheeler, W.M. 1908e: 433 (q.m.); Wheeler, G.C. & Wheeler, J. 1953b: 74 (l.). Junior synonym of tepicana: Creighton & Gregg, 1955: 24.
 * torpescens. Pheidole kingi subsp. torpescens Wheeler, W.M. 1915b: 404 (s.w.) U.S.A. Junior synonym of tepicana: Creighton & Gregg, 1955: 24.

Type Material
Mexico Tepic, Nayarit, collected by Eisen and Vaslit. and  - as reported in Wilson (2003)

Description
From Wilson (2003): DIAGNOSIS A member of the “pilifera complex” of the larger pilifera group; for a characterization of the complex, see under Pheidole pilifera.

P. tepicana is distinguished within the complex as follows. Trimorphic, with major, supermajor, and minor castes.

Major: posterior half of dorsum of head except for occiput smooth and shiny; pronotum low and smoothly convex; mesonotal convexity very low; postpetiole from above diamond-shaped. Supermajor: posterior third of head covered by a mixture of rugulae and rugoreticula; rugoreticulum present between eye and antennal fossa.

Minor: propodeal spines reduced to denticles; head almost entirely smooth and shiny.

MEASUREMENTS (mm) Major (Austin, Texas): HW 1.12, HL 1.34, SL 0.62, EL 0.12, PW 0.54. Supermajor (Guadalajara, Mexico): HW 1.62, HL 2.00, SL 0.74, EL 0.14, PW 0.74. Minor (Austin, Texas): HW 0.52, HL 0.56, SL 0.52, EL 0.12, PW 0.32.

COLOR Major: reddish yellow.

Supermajor: light reddish brown.

Minor: brownish yellow.



'''Figure. Upper: major (plus partial frontal head view of a supermajor). Lower: minor. TEXAS: major and minor from Austin (syntypes of the synonymy kingi subsp. instabilis Emery); supermajor from Guadalajara, Jalisco, Mexico. Scale bars = 1 mm.'''

Etymology
Name based on type locality. (Wilson 2003)