Temnothorax politus

Smith (1939) reported: the workers of this ant seem to be most commonly found on the ground in the vicinity of irrigation canals, washes, and rivers. Specimens have been taken at altitudes up to 4,500 feet. They are rather shy and sensitive to heat. Little else is known of their biology except that one nest was found in the bark of a cottonwood tree, about 2 inches above the surface of the soil.

Identification
The worker of this species is characterized by its strongly convex, evenly arched thorax; absence of dorsal thoracic sutures; peculiarly shaped petiole, the peduncle of which is approximately the length of the petiolar .node; the smooth and shining surface of the body; and the general black color.

Distribution
United States: Central and southern Arizona.

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

Abundance
Only collected twice.

Castes
Known only from the worker caste.

Nomenclature

 *  politus. Macromischa polita Smith, M.R. 1939e: 506, pl. 1, fig. B (w.) U.S.A. Combination in Leptothorax: Baroni Urbani, 1978b: 478; in Temnothorax: Bolton, 2003: 272.

Worker
Worker (PI. I, B). Length 2-2.4 mm.

Head, exclusive of mandibles, subrectangular, slightly longer than broad; posterior border faintly convex; occipital angles strongly rounded, and sides moderately convex. Eye convex, removed by at least the length of its greatest diameter from base of mandible. Antenna 12-segmented; scape slender, extending farther posteriorly on head than scape of floridana; first funicular segment approximately length of the three succeeding segments combined, club 3-segmented, as long as remainder of funiculus. Clypeus convex, more strongly projecting than that of subditiva, posterior border rounded and extending well back between frontal carinqe. Frontal area small, triangular, poorly defined. Mandible 5-toothed, the two apical teeth clearly visible. Thorax short, robust, in profile with strongly convex and rather evenly arched dorsum; from above somewhat broader anteriorly than posteriorly, with rounded humeral angles and no promesonotal or mesoepinotal sutures; epinotal spines large, at least twice length of their interbasal space. Femora and tibiae incrassate, especially those of the posterior pair of legs. In profile, petiolar peduncle short, approximately length of bulbous node, which has subvertical anterior and posterior surfaces, and an evenly convex dorsal surface; peduncle with a small ventral footh; from above, petiolar node somewhat campanulate; postpetiole transversely elliptical, approximately one and one-half times as broad as petiolar node. Base of gaster with strong angles.

Head, thorax, petiole, postpetiole, gaster, femora, and tibiae smooth and shining; mandibles longitudinally striate, clypeus with a prominent median carina and several lateral rugulae, cheeks and anterior portion of each frontal carina with longitudinal rugulae, meso- and metapleura of thorax longitudinally rugulose punctate.

Hairs grayish, slender, erect, moderately abundant on all parts of body; shorter and more suberect on appendages.

Black; with lighter mandibles, epinotal spines, coxae, trochanters, bases of femora, tibiae, and tarsi.

Type Material
Tucson area, Phoenix, Florence, Arizona. Cotypes.-No.'53249,. Described from 26 specimens, collected by Robert G. Wesson. All these are in the United States National Museum collection except the following: 2 workers from Phoenix, Robert G. Wesson; 2 workers from along Santa Cruz River, AMNH; 2 workers from along Santa Cruz River,.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1978. Materiali per una revisione dei Leptothorax neotropicali appartenenti al sottogenere Macromischa Roger, n. comb. (Hymenoptera: Formicidae). Entomol. Basil. 3: 395-618.
 * Johnson R. Personnal Database. Accessed on February 5th 2014 at http://www.asu.edu/clas/sirgtools/resources.htm
 * Smith M. R. 1939. Ants of the genus Macromischa Roger in the United States (Hymenoptera: Formicidae). Annals of the Entomological Society of America 32: 502-509.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133