Pheidole tetra

In the Ouachita Mts. of Arkansas, Stefan Cover (unpublished field notes) found colonies at three localities in open areas of mixed pine-hardwood forest, nesting beneath rocks. At the Pedernales Falls State Park, Blanco Co., Texas, he found two colonies under rocks in grassy clearings, nesting in sandy soil; and in Cochise Co., Arizona, Cover discovered a colony in cottonwood floodplain forest, apparently nesting in open soil. In western Texas, Moody and Francke (1982) found tetra at 400–1600 m, nesting variously under stones and logs and in open soil. (Wilson 2003)

Identification
This species can be recognized as the base of the scape is flattened, with the dorsal surface slightly concave; and the scapes extend about 2/3 of the distance to the posterior lateral corners. The flattened area of the scape is about equal in width to the diameter near the apex of the scape. The anterior 2/3 of the head is roughly sculptured, with coarse, reticulated rugae, with the intrarugal spaces punctate. The posterior 1/3 of the head is finely sculptured and moderately to strongly shining; the tops of the posterior lateral lobes have only piligerous punctures and are glossy and shiny. The dorsum of the pronotum is finely sculptured, and mostly smooth and glossy. The posterior 1/2 of the mesonotum is swollen into a protuberance; the propodeal spines are moderately slender, and well developed. The lateral connules on the postpetiole are poorly developed. Most surfaces of the minor worker are densely and evenly punctate, only the central portion of the head and the side and dorsum of the pronotum are smooth and glossy. The gaster is smooth and glossy. (Mackay and Mackay 2002)

Also see the description in the nomenclature section.

Key to the Pheidole of the United States

Distribution
Known from St. Louis Co., Missouri; Ouachita Mts., Montgomery Co., Arkansas; central and western Texas; and the mountains of southern Arizona at 1280–1580 m. (Wilson 2003)

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

Biology
This ant nests in soil, with entrance surrounded by a small mound. Workers are group foragers.

Castes
Minor

Nomenclature

 *  tetra. Pheidole crassicornis subsp. tetra Creighton, 1950a: 176 (s.w.) U.S.A. [First available use of Pheidole crassicornis subsp. porcula var. tetra Wheeler, W.M. 1908e: 467; unavailable name.] Raised to species: Wilson, 2003: 161.

Description
From Wilson (2003): Very close to Pheidole crassicornis, from which it differs in the major by its generally abundant pilosity, and Pheidole diversipilosa, from which it differs in the longer pilosity on the first gastral tergite and abundant hairs on the waist and occiput. Also resembles Pheidole porcula in various traits as depicted.

MEASUREMENTS (mm) Lectotype major: HW 1.34, HL 1.36, SL 0.72, EL 0.20, PW 0.66. Paralectotype minor: HW 0.66, HL 0.74, SL 0.74, EL 0.14, PW 0.44.

COLOR Major and minor: concolorous light to dark reddish brown.



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

Type Material
TEXAS: Austin, col. W. M. Wheeler. - as reported in Wilson (2003)

Etymology
Gr tetra, four, significance unknown. (Wilson 2003)