Hypoponera opaciceps

Most species in this genus are more or less cryptobiotic, foraging in leaf mold. They are frequently found nesting in decaying wood.

Identification
The relatively coarse, subopaque body sculpture, the shape of the head and petiole are the main distinguishing features for this species (Kempf 1962).

Distribution
This species ranges from as far north as Boulder, Colorado, in the United States to as far south as Uruguay, South America, and throughout the islands of the West Indies (Smith, M.R. 1936).

This taxon was described from Brazil.

It is also found in the United States, New Caledonia, Mexico, Philippines, Ecuador, New Guinea, Uruguay, Peru, Argentina, Paraguay, Guyana, Guatemala, Panama, Costa Rica, Haiti, Dominican Republic, Puerto Rico, Bermuda, Bahamas, Japan, Fiji, Samoa, Tonga, Palau, Micronesia (Federated States of), Trinidad and Tobago and Hawaii.

Biology
Smith (1929) reports on a nest being taken from a partly decayed pine stump (Ocean Springs, MS).

Nomenclature

 *  opaciceps. Ponera opaciceps Mayr, 1887: 536 (w.q.) BRAZIL. Smith, M.R. 1929: 545 (m.); Wheeler, G.C. & Wheeler, J. 1964b: 453 (l.). Combination in Hypoponera: Taylor, 1967a: 11. Senior synonym of perkinsi (and its junior synonym andrei): Wilson & Taylor, 1967: 28; of postangustata: Wild, 2007b: 54. Current subspecies: nominal plus cubana, gaigei, jamaicensis, pampana,. See also: Smith, M.R. 1936: 428; Wheeler, W.M. 1937c: 59; Kempf, 1962b: 7.
 * andrei. Ponera andrei Emery, 1900c: 318 (footnote), pl. 8, fig. 47 (w.) NEW CALEDONIA. Junior synonym of perkinsi: Wilson, 1958d: 334.
 * perkinsi. Ponera perkinsi Forel, 1899a: 117 (w.q.m.) HAWAII. Senior synonym of andrei: Wilson, 1958d: 334. Junior synonym of opaciceps: Wilson & Taylor, 1967: 28. See also: Wheeler, W.M. 1909c: 271.
 * postangustata. Ponera opaciceps var. postangustata Forel, 1908c: 343 (w.) PARAGUAY. Combination in Hypoponera: Kempf, 1972a: 123. Junior synonym of opaciceps: Wild, 2007b: 54.

Worker
Smith (1936) - Length: 3.2-3.4 mm. Head, excluding mandibles, longer than broad, posterior border faintly emarginate, the sides convex, and the posterior angles rounded. Eyes small, with approximately 10-12 facets, situated at a distance less than twice their greatest diameter from the base of the mandibles. Mandibles with more irregular teeth than with P. pennsylvanica, the front teeth not only larger but more regular. Clypeus convex medianly. No frontal area. A faint frontal furrow extends half the distance or beyond from the frontal carinae to the posterior border of the head. Scape not attaining the posterior border of the head; the funiculus clavate, the last segment apparently shorter than the three preceding segments. Thorax with distinct promesonotal and meso-epinotal sutures, not so laterally compressed, especially about the epinotum as with P. pennsylvanica; epinotal declivity faintly concave, with bluntly marginate sides, meeting the base in a well rounded, obtuse angle. Petiole viewed in lateral profile thick antero-posteriorly, scarcely narrower dorsally, convex anteriorly, concave posteriorly; viewed posteriorly the superior border merges into the sides in well rounded angles; tooth below although rectangular, apparently lacking the spiracular opening in front, and the point posteriorly, as with P. pennsylvanica.

Head, thorax, petiole, and gaster very densely and finely punctate, subopaque; meso- and meta-pleurae finely and longitudinally striated; mandibles, and epinotal declivity rather smooth and shining.

Pubescence yellowish gray, dense and appressed, covering all parts of the body. Hairs grayish, very noticeable on the clypeus and gaster where they are longest and most abundant; usually found sparingly on other parts of the body.

Color varying from brown to black; mandibles, antennal funiculi, legs and tip of gaster lighter.

Queen
Smith (1936) - Length: 3.7-4 mm. So similar to the worker as to hardly warrant a brief description. Very slightly larger. Compound eyes placed at a distance from the mandibles less than their greatest diameter. Frontal furrow extending to the anterior ocellus. Petiole proportionally smaller and narrower anteroposteriorly on the dorsal border than with the worker. Wings very hyaline, with light yellowish veins and stigma, each with a submarginal and discoidal cell.

Smith (1936) - Ergataner. - Length of head .68-.76 mm.; length of thorax .935-.965 mm. Head, including mandibles, longer than broad; posterior border almost straight, and sides subparallel, thus giving the head a more rectangular appearance than with the worker. Mandibles moderately broad, triangular, edentate stubs. Clypeus strongly convex, protuberant. Antennae 13-segmented, gradually but not strongly enlarging distally; scapes short, subcylindrical, approximately equal in length to the second, third, and fourth segments of the funiculi taken together. Compound eyes small, almost circular, separated from the base of the mandibles by a space equivalent to approximately one and one-half times their greatest diameter. Thorax short, robust; viewed laterally the pro-mesonotal and meso-epinotal sutures are very distinct, especially on the dorsum; mesonotum strongly gibbous, clearly projecting above the general surfaces of the pronotum and epinotum. Between the mesonotum and epinotum the suture is represented by a very strong constriction, following which, the epinotum forms a rather long and gentle arch terminating at the petiole. The basal surface and declivity of the epinotum merge into each other so gradually that they are hardly distinguishable. Petiole large, robust, anterior and posterior faces convex, superior border rounded. Gaster similar to that of the worker, but bearing prominent genital appendages.

Color sordid yellow; margins of compound eyes and antennal cavities black, articulations of legs and sutures of thorax brown.

The above description is based on two specimens which were taken from a colony of Ponera opaciceps at Landon, Mississippi, by G. W. Haug on August 25, 1930. No other ergataners of this species have been seen or recorded.

Type Material
Reported by Smith (1936) - Province of Saint Catherine, Brazil (Mayr).