Nothing is known about the biology of this species.
Lattke (2004) - The elongate habitus of this species, especially the rectangular head shape, is reminiscent of similar morphologies seen in the laevior group. The presence of propodeal teeth in G. ortostoma precludes its inclusion in the laevior group, which lacks propodeal armature.
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
Not much is known about the the biology of Gnamptogenys ortostoma. 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.
Males are unknown.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- ortostoma. Gnamptogenys ortostoma Lattke, 2004: 139, fig. 31 (w.q.) SINGAPORE.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Head subrectangular in frontal view, with anterior margin of clypeal lamella relatively straight to slightly concave, laterally angular; mandibular dorsum mostly smooth with piligerous punctae. Lateral pronotal face densely foveolate, anteroventral corner forming acute angle; humeral angle lamellate.
- Holotype, worker, Bukit Timah Nature Reserve, Singapore, Murphy,D.H., ANIC32-017689, Australian National Insect Collection.
Metrics. [Holotype] Paratype (n = 1): HL [0.94] 0.98, HW [0.70] 0.74, ML [0.42] 0.38, SL [0.76] 0.83, ED [0.18] 0.20, WL [1.24] 1.23 mm. CI [0.78] 0.76, SI [1.09] 0.97, MI [0.60] 0.51, OI [0.26] 0.24. Head subrectangular in frontal view, lateral margins straight to broadly convex, posterior margin broadly concave, anterior margin of clypeal lamella straight to slightly concave, laterally angular; frons densely punctate, almost areolate, ridges between depressions rounded, not sharp; fine median longitudinal sulcus extends from posterior clypeal margin to eye height; clypeus smooth with round punctures, lamella rugulose-scrobiculate; scape mostly smooth with scattered punctulae; mandibular dorsum mostly smooth with piligerous punctae, punctae deeper and more elongate basally; occipital lobe well developed, lamella narrow, angular at ends.
Lateral pronotal face densely foveolate, anteroventral corner forming acute angle; humeral angle well developed, lamellate; anepisterum mostly smooth with scattered punctae; metapleuron mostly smooth; mesosomal dorsum densely foveolate, promesonotal suture impressed as brief transverse line, laterally obliterated; propodeal declivity mostly smooth, bordered by carina contiguous with propodeal denticles. Petiolar node evenly convex in lateral view, ventral process forming anteriorly projecting lobe, dorsum smooth with foveolae; postpetiolar dorsum mostly smooth with scattered punctae, punctae deeper and more abundant anterad than posterad, laterally with deeper and more punctae than dorsally; sternum mostly smooth with scattered punctae; dorsum of abdominal segment 4 mostly smooth with scattered punctulae. Fore coxa smooth in lateral view; fore tarsus opposite strigil with single stout seta; metacoxal tooth slender, triangular, relatively straight. Dorsum of thorax and abdominal segments 1-4 with scattered erect to subdecumbent hairs. Head, mesosoma, petiole, and gaster dark brown to black; mandibles, antennae, legs ferruginous.
Metrics (n = 1): HL 0.94, HW 0.73, ML 0.44, SL 0.74, ED 0.23, WL 1.34 mm. CI 0.78, SI 1.01, MI 0.60, OI 0.21. Pronotum areolate, with almost denticle-like anteroventral corner in lateral view; mesonotum mostly longitudinally rugulosepunctate; mesopleuron mostly smooth with scattered foveolae; dorsal propodeal face areolate. Metacoxal tooth stout, arched.
The species name is derived form a conjugation of the Greek words for “straight,” orthos, and “mouth,” stoma (n.).
- 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 139, fig. 31 worker, queen described)