Poneracantha semiferox

A millipede hunter known from rain forests between 900-1200 m on Hispaniola. Also suffering from habitat shrinkage due to deforestation (Lattke 1995).

Identification
A member of the semiferox complex (in the banksi subgroup of the rastrata species group). In the development of the mandibles, semiferox is intermediate between Gnamptogenys schmitti and Gnamptogenys banksi on the one hand and Gnamptogenys mediatrix on the other. In sculpture, semiferox is closest to schmitti, but shows tendencies toward the irregular, coarse, partly reticulate or punctate sculpture even better developed in banksi. The mandibles of semiferox are differ from schmitti, including in cross section: shining and longitudinally rugulose, as opposed to opaque and striate in schmitti. In the lack of a dorsal tooth on the posterior coxa, and in the smooth postpetiolar sternum, schmitti and semiferox are alike and distinctive, but other Gnamptogenys lack the coxal armament, and banksi has a partly smooth postpetiolar sternum (from Brown 1958 and Lattke 1995).

Key to New World Gnamptogenys Species

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

Nomenclature

 *  semiferox. Gnamptogenys semiferox Brown, 1958g: 324, fig. 14 (w.) DOMINICAN REPUBLIC.

Lattke (1995): Diagnosis - Body with abundant coarse punctation, especially on head; mandibles with about six denticles and projecting basal lobe; anterior clypeal margin convex; declivitous propodeal face longitudinally costulate.

Worker
Holotype worker: TL 7.0, HL 1.43, HW (across eyes) 1.44, HW (at anterior corners) 1.39, closed mandibles extend about 0.81 mm., WL 1.99, petiole L 0.74, greatest eye diameter 0.29, scape L 1.11, absolute exposed length of left mandible 1.32; CI 97. Differs from Gnamptogenys (=Emeryella) schmitti workers of about the same size in its narrower head; shorter, broader, differently formed mandibles; and in the longer petiolar node, which is a trifle longer than broad seen from above. The median clypeal lobe is more prominent, and its anterior border is entire and evenly convex in outline. The sculpture differs in a number of ways.

The costulation throughout, but particularly on the head and pronotum, is finer, less uniform and even, less shining, and a little less distinct. The interspersed punctation, very sparse and insignificant in schmitti, is more abundant, coarser and considerably more distinct in semiferox, especially on the head, but it still does not interfere seriously with the regularity of the costulation except in the areas just mesad of the compound eyes and on the dorsolateral surfaces of the propodeum. The punctures are mostly indistinctly bounded, but contain piligerous tubercles. The dorsal face of the propodeum is longitudinally and subvermiculately costulate (evenly and transversely in schmitti). Color deep piceous, as in fully pigmented schmitti, appearing black to the naked eye. The appendages are more reddish.

Type Material
The holotype and two very similar paratypes (Coll. Borgmeier, MCZC) all bear the same data: Mt. Diego de Ocampo, 3000-4000 feet altitude, Dominican Republic, July, 1938 (P. J. Darlington leg.). Dr. Darlington tells me that the type locality was chiefly rain forest in which small palms were prominent, but that the land was being cleared for agriculture even at the time of his visit.