Hypoponera inexorata

Nests and workers are found below ground, sometimes under stones, and nests are often near other ant species. Colony size is less than 20 workers. With its tiny workers, underground nesting habits and small colony size this ant species is not commonly collected. (Navajo Nature, 2010).

Identification
Small ants with minute eyes and a head that is finely punctate and much longer than broad. In viewing the head in full face view, the posterior margin is slightly concave and the mandibles are sinuate along their outer border.

This species is recognized in the United States fauna by its orange color, relatively large size, and sinuate outer border of the mandibles. Confidence with the latter feature requires a little practice, or comparison with species that have convex outer borders to the mandibles. An unidentified southwestern species that resembles H. inexorata in size and color lacks the sinuate mandibles. There is a little variation in size, as in other species of Hypoponera, but this seems to have no geographic basis. Specimens from different regions and habitats, such as the beaches of south Florida and the sandhills of north Florida, seem structurally identical. Presumed males from Florida are distinguished by their large size (length over 3mm), well-pigmented wing veins, and round eyes.

Distribution
Costa Rica and Mexico north through to South Carolina in the east and Arizona in the west. Through much of its range H. inexorata is known from widely scattered localities, perhaps reflecting the difficulty of collecting an ant that is usually subterranean

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



Biology
Nests and workers are found below ground, sometimes under stones, and nests are often near other ant species. Colony size is less than 20 workers. With its tiny workers, underground nesting habits and small colony size this ant species is not commonly collected

This species has been found in dry coastal hammocks, Florida scrub and sandhill habitats in Florida. Specimens are found under objects or in sand, or occasionally extracted from leaf litter in dry habitats. Complete colony are yet to be found. Ergatoid males have not been seen and neither have large-eyed females without wings or wing stubs. Alates have been collected in Florida in June and July.

Mississippi
Joe MacGown, Ants (Formicidae) of the southeastern United States: This species has recently been collected in Black Belt Prairie remnants in MS. Colonies have been found underneath the soil by random digging. At least one colony has been found underneath an imported fire ant colony (Pers. Comm. JoVonn G. Hill).

Texas
Wheeler (1903) reported: I have found it only on dry hill-slopes under rather small stones (limestone in central Texas, volcanic rock in the Trans-Pecos).

Nomenclature

 *  inexorata. Ponera inexorata Wheeler, W.M. 1903b: 94, fig. 2 (w.q.) U.S.A. Combination in Hypoponera: Taylor, 1968a: 65. Current subspecies: nominal plus fallax.

Worker
Length: 2.75-3.25 mm. Mandibles long and flattened, with concavely sinuate lateral borders and about a dozen teeth, which are small and indistinct toward the base, but longer and more pointed toward the tips of the blade. Head distinctly longer than broad with concave occipital margin and subparallel sides. Clypeus broadly rounded in front, convex in the middle. Antennae rather slender, scape reaching to the posterior angle of the head, joints 2-5 of the funiculus fully as long as broad, the remaining joints longer than broad. Eyes very small, with at most 3-4 ommatidia in their longest diameter and situated about one-fourth the distance from the anterior to the posterior border of the head. Thorax with very distinct pro-mesonotal and mesoepinotal sutures; pronotum broader then the succeeding thoracic segments, rounded, with rather sloping anterior angles; mesonotum convex; epinotum laterally compressed, its basal portion in profile horizontal and nearly straight, its declivity flattened, with rounded sides, not carinate. Petiole decidedly narrower than the first gastric segment, its anterior surface flattened dorsoventrally but distinctly convex from side to side; posterior surface flat in both directions, so that the segment when seen from above is somewhat semicircular; seen from behind the border of the node is nearly circular in outline. Gaster of the usual form. Legs moderately stout, each tibia with a pair of spurs, one of which is pectinated.

Surface of the body, especially the dorsal surface of the head, thorax, and petiole, shining. Mandibles with coarse, scattered, piligerous punctures. Head covered rather densely but not confluently with coarse piligerous punctures or small foveolae. Pronotum with similar but smaller and sparser punctures; neck and mesonotum finely corrugated above; meso- and metapleura similarly but more coarsely sculptured, subopaque. Petiole and gaster covered with piligerous punctures like those on the pronotum.

Whole body clothed with pale yellow, reclinate or appressed hairs, among which there are longer, more scattered, suberect hairs, especially on the thorax and abdomen.

Yellowish ferruginous throughout, mandibles, antennae, and legs somewhat paler. Epinotum, mesopleurae, and posterior gastric segments sometimes more reddish or brownish. Teeth of mandibles and anterior border of clypeus blackish.

Queen
Dealated. Length: 3.25 mm. Very much like the worker in form and coloration. Each ocellus with a small black spot at its margin. Head distinctly more opaque than in the worker, owing to a denser aggregation of the piligerous foveolae; the node is thinner antero-posteriorly and its anterior surface is very flat or evenly slightly concave from side to side. Alar insertions black.

Type Material
Described from two females and numerous workers, taken at Austin, San Angelo, and Fort Davis (Texas).