Xenomyrmex floridanus skwarrae

The types were collected from an epiphyte (Tillandsia circinnata).

Identification
This beautiful species is very easily recognized and very unlike the other continental species. It resembles Temnothorax isabellae Wheeler of Puerto Rico in the shape of the thorax and petiole, but is very different in sculpture and coloration. (Wheeler 1931)

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Nomenclature

 *  skwarrae. Xenomyrmex stolli subsp. skwarrae Wheeler, W.M. 1931a: 137, fig. 2 (w.q.m.) MEXICO. Senior synonym of castus: Creighton, 1957c: 8. Currently subspecies of floridanus: Creighton, 1957c: 8.
 * castus. Xenomyrmex stolli subsp. castus Wheeler, W.M. 1931a: 138 (w.q.m.) MEXICO. Junior synonym of skwarrae: Creighton, 1957c: 8.

Worker
Length 2.6-3.2 mm.

Head subrectangular, slightly longer than broad, as broad in front as behind, its posterior border slightly concave. Eyes moderately large and convex, at the middle of the sides. Mandibles stout and rather broad, with five subequal teeth and rather straight external borders. Clypeus convex, its anterior border broadly rounded and projecting. Frontal area distinct but not impressed. Antennal scapes reaching very nearly to the posterior border of the head; first funicular joint as long as the three succeeding joints together; joints 2-8 as broad as long; club 3-jointed, its two basal joints together somewhat shorter than the more enlarged terminal joint. Thorax rather long, broader through the pronotum, its dorsal profile straight except for a very feeble impression between the meso- and epinotum; base of the latter rounded in profile and nearly twice as long as the sloping concave declivity, armed with two small, blunt, approximated spines, which are somewhat longer than the distance between their bases and directed upward, backward and outward; metasterna large, bluntly angular and turned upward. Petiole rather short, with robust peduncle, armed with a small anteroventral tooth; node low, its anterior surface rising gradually from the peduncle, its posterior surface convex and descending more abruptly to a pronounced constriction of the petiole. Seen from above the node is laterally compressed and but little broader than the peduncle. Postpetiole campanulate, fully 2 ½ times as broad as the petiole, as long as broad, narrowed and evenly rounded anteriorly, posteriorly with subparallel sides. Gaster lenticular, somewhat flattened dorsoventrally, with straight anterior border. Legs long, femora, especially the hind pair, greatly incrassated.

Mandibles, head, thorax, pedicel, antennae and tibiae opaque, gaster and femora somewhat shining, or lustrous. Mandibles coarsely striate, head, thorax and pedicel densely punctate, clypeus and head also longitudinally rugulose, thorax covered with more undulating and irregular rugae, which are somewhat less distinctly longitudinal. Gaster and legs finely and densely reticulate.

Hairs on the body white, short, obtuse, erect and rather sparse, mostly on the dorsal surface; short, acute and appressed on the appendages.

Head, scapes, thorax, petiole and postpetiole deep black; gaster dull yellow with a dark brown band at the posterior border of the first segment. Antennal funiculi, mandibles and legs dark brown, almost black.

Queen
(dealated). Length 5 mm.

Resembling the worker in sculpture, pilosity and color, but the sculpture of the thorax is stronger and more regular, the pronotum and epinotal declivity being transversely, the mesonotum, scutellum and pleurae longitudinally rugulose. Mesonotum as broad as long, flattened above; base and declivity subequal, the latter vertical, the spines in the form of dorsoventrally compressed lobes, less than twice as long as broad, directed backward. Petiole irregularly rugulose; postpetiole fully It times as broad as long, above finely, longitudinally rugulose. Gaster suboblong, more reddish yellow than in the worker, with dark brown bands at the posterior borders of the segments, the one on the first segment being more than twice as broad as the others.

Type Material
Described from several workers and a single female taken by Dr. Elisabeth Skwarra in an epiphyte (Tillandsia circinnata) at Cuernavaca, Morelos, Mexico.