Temnothorax nigricans

The type colony was found in a mahogany twig lying on the ground.

Distribution based on Regional Taxon Lists
Neotropical Region: Cuba, Greater Antilles.

Nomenclature

 * melanocephala. Macromischa melanocephala Wheeler, W.M. 1931b: 15 (w.q.) CUBA. [Junior secondary homonym of Leptothorax melanocephalus Emery, above.] Replacement name: nigricans Baroni Urbani, 1978b: 467.
 *  nigricans. Leptothorax nigricans Baroni Urbani, 1978b: 467. Replacement name for Macromischa melanocephala Wheeler, W.M. 1931b: 15. [Junior secondary homonym of Leptothorax melanocephalus Emery, 1870: 197.] Combination in Temnothorax: Bolton, 2003: 271.

Worker
Length 1.5-1.8 mm.

Head subrectangular, slightly longer than broad, with broadly rounded posterior corners and convex posterior border. Eyes rather large, at the middle of the sides. Mandibles with two stout apical and three small basal teeth, external borders rather straight. Clypeus large, moderately convex, its anterior border entire, broadly rounded and projecting. Frontal area distinct, triangular, with a median carinula. Frontal carinae short. Antennae stout, scapes reaching slightly beyond the posterior border of the head; first funicular joint as long as the three succeeding joints; joints 2-8 subequal, distinctly broader than long; club very distinct, 3-jointed, its terminal joint large, longer than the two basal joints together. Thorax short and stout, less than twice as long as broad, broad through the humeri of the pronotum, which is very large; meso- and epinotum narrowed posteriorly. In profile the thorax is high with convex, evenly rounded dorsal outline and rather long, steep, concave epinotal declivity; spines slender, approximated at the base, as long as the declivity, directed upward, backward and outward and somewhat curved downward. Metasterna small and rounded. Petiole short, the peduncle laterally compressed, without anteroventral tooth; node as long as the peduncle from which it rises abruptly, higher and somewhat broader than long, in profile subcuboidal, from above semicircular. Postpetiole broadly campanulate, fully twice as broad as long and twice as broad as the petiolar node. Gaster rather large, suboval, with straight or slightly concave anterior border. Legs rather short, femora, especially the hind pair, distinctly incrassated.

Mandibles, head, thorax and scapes opaque, remainder of the body somewhat shining, or lustrous, the gaster more than the pedicel and legs. Mandibles finely and indistinctly striated; clypeus longitudinally rugulose; head uniformly and densely punctate, the punctures arranged in regular lines separated by very delicate and rather indistinct rugules. Thorax and pedicel much more finely and densely punctate, in some specimens with indications of fine longitudinal striae on the pronotum. Pedicel finely but more superficially punctate. Gaster and legs smoother, superficially reticulate. Scapes densely punctulate.

Hairs yellowish, sparse, obtuse and erect on the dorsal surface of the body, fine, pointed and appressed on the appendages. Clypeus and head black; mandibles, frontal carinae, antennae, thorax and abdomen pale brownish yellow; antennal clubs infuscated; legs and epinotal spines white or very pale yellow.

Queen
Length 2-2.3 mm.

Head more rectangular than in the worker, fully as broad as long. Thorax very broad and robust, the mesonotum subrectangular, flattened and longer than the scutellum and epinotum together. Epinotal spines stout, acute, scarcely longer than their distance apart at the base, directed backward and curved somewhat inward and downward. Sculpture, pilosity and coloration of head, pedicel and appendages as in the worker but the mesopleurae, wing insertions, posterior border of scutellum, metanotum, an anteromedian spot on the mesonotum, and elongate spots on the paraptera, dark brown. Gaster dark brown, with only the anal region and the anterior portion of the first segment, both dorsally and ventrally, brownish yellow.

Type Material
Described from two females and many workers, constituting a single colony collected at Hacienda Jiqui, Ensenada de Cochinos, Cuba, by Dr. J. G. Myers. They were nesting in a dead twig of mahogany (Swietenia mahagoni) lying on the ground.