Temnothorax bestelmeyeri

This species is only known from a single worker. It was collected in a pitfall trap in desert grassland.

Identification
Prebus 2017 - A member of the sallei clade.

Mackay (2000) - This is a small, pale yellow species with large, black eyes and a 12-segmented antenna. The dorsum of the head is covered with striae formed by closely placed punctures that are in rows. The carinae on the clypeus are poorly formed, the middle carina is lacking, but the entire surface of the clypeus is convex. The top of the mesosoma is covered with fine rugae, the petiolar node is moderately sharp in profile, with the edge formed by a ruga. The subpeduncular process is well developed. The postpetiole is more than 1.5 X the width of the petiole.

This pale yellow ant with large, black eyes would be confused with few other species, except for Temnothorax andersoni, Temnothorax cokendolpheri, Temnothorax liebi and Temnothorax coleenae from the Chihuahuan Desert. See the discussion of T. coleenae for characteristics to separate these species. The large eyes would also separate it from Temnothorax terrigena, Temnothorax furunculus, and Temnothorax andrei.

Distribution
USA. New Mexico. Known only from the type locality.

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

Habitat
The holotype was collected in desert grassland.

Abundance
Only known from the type collection.

Castes
Known only from the worker caste.

Nomenclature

 *  bestelmeyeri. Leptothorax (Myrafant) bestelmeyeri Mackay, W.P., 2000: 318, figs. 26, 41, 42, 87-89 (w.) U.S.A. Combination in Temnothorax: Bolton, 2003: 271.

Worker
Mandibles with 4 teeth plus poorly defined denticles; anterior border of clypeus convex, clypeus without medial carina and poorly defined lateral carinae; eye large, anterior edge to anterior edge of cheek (0.16mm) less than maximum diameter of eye; vertex straight; mesosoma with none of the sutures breaking the sculpture; propodeal spines small (0.06mm in length), but well developed; petiole with well developed, blunt subpetiolar tooth, anterior petiolar face straight, posterior face convex, petiolar node moderately sharp in profile. Erect, blunt hairs scattered on most surfaces, up to 0.12mm in length, legs and scapes with finer hairs, which are nearly decumbent. Dorsum of head punctate with punctures forming costulae, dorsum of mesosoma with fine rugulae, sides similar to sculpture on head, gaster smooth and polished, mesosoma, petiole and postpetiole (sides and dorsum) mostly punctured and rough, dorsum of gaster smooth and shining.

Concolorous pale yellow with black eyes.

Measurements: HL 0.67, HW 0.54, SL 0.49, EL 0.22, WL 0.79, PW 0.19, PL 0.16, PPW 0.29, PPL 0.20. Indices: CI 81, SI 73, PI 113, PPI 145.

Type Material
Holotype worker USA: New Mexico, Dona Ana Co. 37 k N Las Cruces, Jornada Experimental Range, 26 or 29-vii-1996. B. Bestelmeyer.

Etymology
Patronym. Named in honor of Brandon Bestelmeyer, who collected the holotype, as well as other interesting Leptothorax specimens.

References based on Global Ant Biodiversity Informatics

 * Bestelmeyer B. T., and J. A. Wiens. 2001. Local and regional-scale responses of ant diversity to a semiarid biome transition. Ecography 24: 381-392.
 * Mackay W. P. 2000. A review of the New World ants of the subgenus Myrafant, (genus Leptothorax) (Hymenoptera: Formicidae). Sociobiology 36: 265-444.
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.