Gnamptogenys helisa

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

Gnamptogenys helisa casent0900562 p 1 high.jpg

Gnamptogenys helisa casent0900562 d 1 high.jpg

Specimen Labels

The type series of Gnamptogenys helisa was taken from a pitfall trap.

Identification

Lattke (2004) - This species is similar to Gnamptogenys crassicornis, but G. crassicornis is on average much lighter colored, usually ferruginous, with totally strigulose scapes and smooth ground sculpture, and is lacking the striae of G. helisa. G. crassicornis is smaller (HL < 1.6; WL < 2.2 mm). This species shares with Gnamptogenys scalpta the fine striations on the body, but G. scalpta is a smaller species (HL < 1.0; WL < 2.2 mm), with mostly strigulose scapes, the anterior margin of its clypeal lamella is more sinuate, not rapidly converging to a median lobe as in G. scalpta. The petiolar node in G. scalpta when seen laterally is evenly convex, with its subpetiolar process subquadrate in shape, and it lacks propodeal denticles. The standing hairs on the body of G. helisa are relatively shorter than in other examined species of Gnamptogenys.

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Indonesia, Malaysia.


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 helisa. 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 unknown.

Nomenclature

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

  • helisa. Gnamptogenys helisa Lattke, 2004: 119, fig. 26 (w.) BORNEO.

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

Occipital lamella convex, wider medially than at ends, ends bluntly angular. Pronotum punctate with mixed smooth-striate areas in lateral view; striae form semicircle from ventral margin to posterior margin, around broad and shallow posteroventral depression. Petiolar node with broadly convex anterodorsal margin in lateral view, posterior margin brief, sharply dropping; ventral process projecting anterad as pointed denticle. Postpetiolar dorsum mostly smooth with abundant punctae; each puncture abruptly impressed anterad and sloping posterad, each puncture also marked by patch of striae.

Description

Worker

Lattke 2004 Gnamptogenys fig 25-27

Metrics. [Holotype] Paratypes (n = 6): HL [1.77] 1.66-1.89, HW [1.44] 1.35-1.45, ML [0.94] 0.89-0.95, SL [1.64] 1.63-1.81, ED [0.27] 0.25-0.27, WL [2.57] 2.42-2.57 mm. CI [0.82] 0.76-0.83, SI [1.14] 1.18-1.26, MI [0.65] 0.63-0.68, OI [0.18] 0.17-0.20. Head with subparallel lateral margins in frontal view, posterior margin concave, anterior margin of clypeal lamella converging into median blunt point; frons strigulose-punctate including vertex; clypeus longitudinally strigulose, strigulae extending onto lamella; scape mostly smooth with scattered longitudinal strigulae; small occipital lobe present; occipital lamella convex, wider medially than at ends. Pronotum with anteroventral angle in lateral view, humeral angle well developed, not lamellate; pronotum laterally punctate with mixed smooth-striate areas, striae forming semicircle from ventral margin to posterior margin, around broad and shallow posteroventral depression; pronotum punctate in dorsal view, punctae united by strigulae, forming posteriorly diverging rows, posteromedian smooth area present; anepisternum mostly smooth with variable amount of strigulae; katepisternum strigulose-punctate; metapleuron anterodorsally smooth, posteroventrally strigulose; mesometanotum and propodeal dorsum punctate with low, partially effaced, transverse strigulae, strigulae may swirl on mesonotum; propodeal declivity anteromedially strigulose, rest mostly smooth; propodeal side mostly smooth with scattered punctae.

Petiolar node with broadly convex anterodorsal margin in lateral view, posterior margin brief, sharply dropping; dorsum punctate with transverse strigulae; ventral process projecting anterad as pointed denticle; postpetiolar dorsum mostly smooth with abundant punctae, each puncture abruptly impressed anterad and sloping posterad, each puncture also marked by patch of striae; postpetiolar sternum with low oblique to transverse strigulae, especially posterolaterally, anteromedially mostly smooth with low longitudinal extending from anterior process to posterior margin; dorsum of abdominal segment 4 mostly smooth with abundant shallow punctae, each one accompanied by striate area, tergite mostly obliquely strigulose in lateral view, sternum carinulate. Fore coxa transversely strigulose in lateral view; fore tarsus opposite strigil with row of stout setae; metacoxal tooth placed on posterior margin. Dorsum of thorax and abdominal segments 1-4 with scattered erect to subdecumbent hairs. Head, mesosoma, petiole, and gaster dark brown; mandibles, antennae, legs ferruginous.

Type Material

Holotype worker. Malaysia, Sarawak, 4th Division, Gunung Mulu Natl. Pk., 1700-1800m, v 1978, I. Hanski. Deposited in BMNH. Paratypes. Seven workers, all from same series as holotype: 4w in The Natural History Museum, 1w in Australian National Insect Collection, 1w in Museum of Comparative Zoology, 1w in Instituto de Zoologia Agricola.

Etymology

The species name is a modification of the Greek term for “turning around,” helisso, which is derived from helix (f.), meaning to spiral or whirl. The epithet alludes to the circling striae on the pronotal sides.

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 119, fig. 26 worker described)