Tapinoma panamense

The type specimens were collected from a colony nesting in a cauline swelling of Cordia alliodora.

Identification
This very small species is evidently quite distinct from Tapinoma ramulorum, Tapinoma atriceps, Tapinoma heyeri and Tapinoma litorale. (Wheeler 1934)

Distribution based on Regional Taxon Lists
Neotropical Region: Panama.

Nomenclature

 *  panamense. Tapinoma panamense Wheeler, W.M. 1934g: 182 (w.q.m.) PANAMA. Senior synonym of canalis: Shattuck, 1992c: 153.
 * canalis. Tapinoma canalis Wheeler, W.M. 1942: 251 (w.q.m.) PANAMA. Junior synonym of panamense: Shattuck, 1992c: 153.

Worker
Length 1-1.2 mm. Head subrectangular, longer than broad, as broad in front as behind, with very feebly convex sides, straight posterior border and rounded posterior corners. Eyes small, fiat, placed about one and one-half times their length from the anterior corners of the head. Mandibles narrow, with oblique apical borders armed with six teeth, the first, second and fourth of which from the tip are large, the others minute. Frontal carinae short, parallel, farther apart than their distance from the sides of the head. Clypeus convex and rounded in the middle, its anterior border straight and entire. Frontal area and groove absent. Antennal scapes not reaching to the posterior corners of the head by a distance equal to their greatest diameter; first funicular joint nearly one and one-half times as long as broad, second small and short, broader than long, remaining joints, except the last, all broader than long but gradually increasing distally in length and thickness. Thorax small, feebly but distinctly impressed at the mesoepinotal suture, otherwise slightly convex in dorsal outline; base of epinotum straight, forming a distinct obtuse angle with the declivity which is decidedly longer. Seen from above the pronotum is nearly twice as broad as long, the mesonotum is subcircular and about as long as broad, the epinotum longer than broad and laterally compressed. Petiole very small and fiat, elliptical, its node represented by a low semicircular swelling at the anterior end, and completely concealed under the large first segment of the elliptical gaster. Legs of the usual shape.

Shining, very finely and indistinctly punctulate.

Hairs and pubescence pale yellow, the former very sparse, distinct only on the mandibles, clypeus and gaster; the pubescence fine and rather dense, slightly obscuring the shining surface, rather long and oblique on the scapes.

Pale brownish yellow; legs scarcely paler; mandibular teeth reddish.

Queen
(dealated). Length 1.8 mm.

Head much as in the worker, but the posterior corners less rounded and the posterior border feebly sinuate in the middle, the eyes larger and more convex, only about half their length from the anterior corners of the clypeus. Scapes shorter, extending to about two-thirds the distance between the eyes and the posterior corners of the head. Thorax slightly narrower than the head, elongate subelliptical, depressed above; pronotum very short and transverse; mesonotum as long as broad, rounded anteriorly; epinotum short, with very short base passing gradually into the long sloping declivity. Petiole as in the worker. Gaster more than three times as long as broad, parallel-sided, first segment covering the petiole and provided with a very distinct impression for its accommodation.

Subopaque and more densely punctulate than the worker; pilosity and pubescence very similar; head and thorax pale yellowish brown, gaster dark brown; mandibles, antennae, legs and broad margins of the gastric segments brownish yellow.

Male
Length about .8 mm.

Head subrectangular, longer than broad, somewhat narrowed behind. Eyes flattened, as long as about half the length of its sides. Mandibles rather well-developed, overlapping, with very minutely denticulate apical borders. Clypeus with straight, entire anterior border. Antennal scapes reaching to the posterior corners of the head; basal funicular joints slightly, terminal joints considerably longer than broad. Thorax as broad as the head. Petiole very much as in the worker. Gaster short.

Sculpture and pilosity as in the worker. Color pale sordid yellow. Wings grayish, pubescent, rather opaque, with pale brownish veins.

Type Material
Specimens from a single colony which I found nesting in a cauline swelling of Cordia alliodora on Barro Colorado Island, Panama.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * INBio Collection (via Gbif)
 * Wheeler W. M. 1934. Neotropical ants collected by Dr. Elisabeth Skwarra and others. Bulletin of the Museum of Comparative Zoology 77: 157-240.
 * Wheeler W. M. 1942. Studies of Neotropical ant-plants and their ants. Bulletin of the Museum of Comparative Zoology 90: 1-262.