Camponotus sansabeanus



This species builds nests deep in the ground, often under rocks at the surface. It is polymoprhic with larger darker majors and light-yellow colored minors. Colonies are often found in desert regions and foraging is nocturnal.

Identification
Majors have wide heads, and the scape usually just reaches the posterior lateral corner of the head, or passes the posterior lateral corner by less than the first funicular segment. Erect hairs on the head are mostly restricted to the clypeus, but can be found on other parts of the head, and even the sides of the head and ventral surface of the head. The base of the scape is flattened and may even be lobe-like. The color ranges from pale yellow to black, most specimens are bicolored with the head darker than the remainder of the ant. Females are similar, except the scapes are relatively longer and the head is usually noticeably widened near the level of the eye. The petiole of the female is slender in profile, with a sharp apex, the anterior face near the apex is slightly concave. The scape of the male is not flattened at the base. Specimens from southeastern Arizona (Cochise Co.) and western New Mexico (Grant Co.) often have erect hairs along the sides of the head. (Mackay and Mackay 2002)

Distribution
Arkansas and Louisiana westward to, and throughout, the southwestern United States; northern Mexico.

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

Habitat
In New Mexico, where this ant is common (Mackay and Mackay 2002): Sagebrush, pinyon-juniper (most common in this habitat), oaks, ponderosa pine, Chihuahuan pine, rocky ridges near pines.

Biology
For New Mexico (Mackay and Mackay 2002): The nests are usually found under stones, but may be in (and under) rotten stumps and logs, or even under cow manure (especially founding gynes and young nests), in rocky, gravely or loam soils. Brood and reproductives were found in nests in August and September. Dealate females were found in March, May and June and September. This species forages diurnally. Workers are timid and escape when the nest is disturbed. One colony was nesting together with Forelius.

Nevada, Wheeler and Wheeler (1986) - We have 18 records from 18 localities scattered south of the 40th Parallel; 4,700-7,500 ft. All localities are in the Pinyon-Juniper Biome. Six nests were under stones; 7 were exposed with the entrance surrounded by excavated soil in various shapes.

Nomenclature

 *  sansabeanus. Formica sansabeana Buckley, 1866: 167 (s.w.q.m.) U.S.A. Wheeler, G.C. & Wheeler, J. 1953e: 196 (l.). Combination in Camponotus: Mayr, 1886c: 365; in C. (Myrmoturba): Forel, 1914a: 267; in C. (Camponotus): Emery, 1920b: 255; in C. (Tanaemyrmex): Creighton, 1950a: 378. Junior synonym of marginatus: Mayr, 1886d: 423. Revived from synonymy as subspecies of marginatus: Dalla Torre, 1893: 242. Subspecies of maculatus: Emery, 1896d: 371; Wheeler, W.M. 1910d: 307. Revived status as species: Emery, 1920b: 232 (footnote); Cole, 1942: 387; Creighton, 1950a: 378. Senior synonym of bulimosus, torrefactus: Wheeler, G.C. & Wheeler, J. 1986g: 14.
 * bulimosus. Camponotus maculatus subsp. bulimosus Wheeler, W.M. 1910d: 308 (s.w.q.m.) U.S.A. Combination in C. (Myrmoturba): Forel, 1914a: 267; in C. (Camponotus): Emery, 1925b: 75; in C. (Tanaemyrmex): Creighton, 1950a: 379. Subspecies of sansabeanus: Emery, 1920b: 232 (footnote); Creighton, 1950a: 379. Junior synonym of sansabeanus: Wheeler, G.C. & Wheeler, J. 1986g: 14.
 * torrefactus. Camponotus (Camponotus) sansabeanus var. torrefactus Emery, 1925b: 75 (s.w.m.) U.S.A. [First available use of Camponotus maculatus subsp. sansabeanus var. torrefactus Wheeler, W.M. 1910d: 308; unavailable name.] Combination in C. (Tanaemyrmex): Creighton, 1950a: 379. Subspecies of sansabeanus: Cole, 1942: 388; Creighton, 1950a: 379. Junior synonym of sansabeanus: Wheeler, G.C. & Wheeler, J. 1986g: 14.

Worker
Wheeler (1910) – Major Length, 9-11 mm.; head, 2.8 x 2.7 mm.; scape, 2.5 mm.; hind tibia, 2.5 mm.

Resembling Camponotus maccooki but stouter, more thick-set, with proportionally larger head and shorter legs. The flattened dilatation at the base of the antennal scape is broader than in vicinu8, but slightly narrower and less lobulate than in maccooki. Clypeal carina blunter, lobe of the anterior border shorter.

Sculpture and pilosity as in maccooki, but lower surface of head with more numerous erect hairs. Cheeks with a very few erect hairs arising from some what elongated foveolae. Pubescence very short and sparse.

Color much like that of maccooki, but thorax more brownish, basal half of gaster yellow or yellowish brown, apical half and sometimes the whole gaster more infuscated.

Minor Length, 5-7 mm.

Antennal scapes less dilated at the base than in the worker minor of maccooki. Cheeks without erect hairs. Color much like that of the worker major.