Gnamptogenys delta

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Gnamptogenys delta
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ectatomminae
Tribe: Ectatommini
Genus: Gnamptogenys
Species: G. delta
Binomial name
Gnamptogenys delta
Lattke, 2004

Gnamptogenys delta casent0911162 p 1 high.jpg

Gnamptogenys delta casent0911162 d 1 high.jpg

Specimen Labels

Only known from the holotype worker, nothing is known about the biology of this species.

Identification

Lattke (2004) - Other species of the laevior group with a smooth to almost glabrous sculpturing on the median clypeus and mandibles are Gnamptogenys biloba, Gnamptogenys hyalina, and Gnamptogenys leiolabia. These species can be separated from G. delta by the presence of two distinct longitudinal ridges that extend from the anterior end of the frontal carinae down to the anterior clypeal margin, a feature lacking in G. delta. These species also have the clypeal lamella with a broadly convex anterior margin, not angular as in G. delta.

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Malaysia (type locality).

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 delta. 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

Queen and male are unknown.

Nomenclature

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

  • delta. Gnamptogenys delta Lattke, 2004: 191, fig. 52 (w.) WEST MALAYSIA.

Lattke (2004) - Head with lateral margins anteriorly convergent in frontal view, forming acute angle continuous with external mandibular margin; clypeal lamella triangular with rounded anteromedian lobe. Propodeal declivity with punctulae along lateral margin, centrally mostly smooth. Foveolae and punctae glazed, without sharp edges.

Description

Worker

Lattke 2004 Gnamptogenys fig 52-53

Metrics. Holotype: HL 0.76, HW 0.63, ML 0.41, SL 0.51, ED 0.18, WL 1.07 mm. CI 0.84, SI 0.81, MI 0.65, OI 0.28. Head with anteriorly convergent lateral margins in frontal view, clypeal lamella triangular with anterior median lobe; round to oval foveolae present on frons, foveolae denser laterally, forming ill-defined posteriorly diverging rows; scape with subdecumbent hairs along dorsal margin; clypeus with a slightly elevated median area, mostly smooth with lateral irregular depressions and sparse punctae on lamella; mandible edentate, mostly smooth, sparsely punctate, with faint strigulae on base; occipital lamella gradually raising from cephalic surface along both ends in lateral view, minute angle present on anterior end.

Mesosoma with abundant foveolae on pronotum in lateral view, intervening space narrower than diameter of depressions except for smooth longitudinal strip parallel to groove along ventral margin; anepisternum rhomboid, mostly smooth with several punctae; katepisternum mostly smooth with low rugulae, plus few foveolae; metapleuron mostly smooth anterad, posteriorly strigulose with some punctae; propodeal declivity with series of punctulae along outer margin, centrally mostly smooth with brief longitudinal strigulae around foramen; mesosomal dorsum with median longitudinal, mostly smooth strip; with sparse foveolae forming ill defined longitudinal rows laterally.

Petiolar node foveolate in lateral view, ventral process subquadrate with concave ventral margin; pospetiole laterally foveolate, deeper and wider anterad than posterad; sternal margin of postpetiole with a brief concavity formed by anterior process in lateral view, followed by straight margin, abruptly convex at posterior margin; postpetiolar dorsum with sparse, shallow piligerous punctae. Fore coxa laterally smooth. Dorsum of thorax and abdominal segments 1-4 with abundant erect to subdecumbent hairs. Body brown; legs, antennae, and mandibles

Type Material

Holotype worker. Malaysia, Pahang, Ringlet, 1250m, ravine no. 20, 26-iii-1993, I. Löbl & Calame. Deposited in Musee d'Histoire Naturelle Genève.

Etymology

The outline formed by the head and mandibles of G. delta is strikingly triangular in dorsal view, consequently the species name is derived from the Greek word for “triangular,” delta.

References

  • Lattke, J. E. 2004. A Taxonomic Revision and Phylogenetic Analysis of the Ant Genus Gnamptogenys Roger in Southeast Asia and Australasia (Hymenoptera: Formicidae: Ponerinae). University of California Publications in Entomology 122: 1-266 (page 191, fig. 52 worker described)