Gnamptogenys semiferox

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Gnamptogenys semiferox
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ectatomminae
Tribe: Ectatommini
Genus: Gnamptogenys
Species: G. semiferox
Binomial name
Gnamptogenys semiferox
Brown, 1958

Gnamptogenys semiferox casent0900545 p 1 high.jpg

Gnamptogenys semiferox casent0900545 d 1 high.jpg

Specimen Labels

Known from the collection of 3 type workers from moist forest between 900-1200 m in the Dominican Republic.

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).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Dominican Republic (type locality), Greater Antilles.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Not much is known about the the biology of Gnamptogenys semiferox. We can speculate that the biology of this species is similar to other species of the genus. Gnamptogenys are predatory ponerine ants that inhabit tropical and subtropical mesic forests. Nesting is typically at ground level in rotten wood or leaf litter. Some exceptions include species that are arboreal, a dry forest species and species that nests in sandy savannahs. Colony size tends to be, at most, in the hundreds. Queens are the reproductives in most species. Worker reproduction is known from a few species in Southeastern Asia. Generalist predation is the primary foraging/dietary strategy. Specialization on specific groups (millipedes, beetles, other ants) has developed in a few species.

Castes

Worker

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

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

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

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.

Description

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.

Holotype Specimen Labels

Type Material

The holotype (Museum of Comparative Zoology) 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.

References