Rhytidoponera aquila

This rainforest species forages on the ground and in low vegetation.

Identification
Known only from the rainforest-covered hills near Touho, Rhytidoponera aquila appears to be related the the complex of opaciventris populations farther west, on the basis of the densely striate, opaque gaster. Rhytidoponera aquila is given species status because of the distinctive striate sculpture which covers most of the head and mesosoma (opaciventris tends towards more rugose sculpture, at least on the pronotum) and because the Touho population is substitued for a unique superoxide dismutase (SOD-1) allele found in no other fulgens-group species. It would be of interest to examine the status of populations in intermediate localities, particularly rainforest areas immediately north-west and south-east of the Tipindje River.

Distribution based on Regional Taxon Lists
Australasian Region: New Caledonia.

Biology
Workers were seen foraging on the ground and on low vegetation, in rainforest between 270 and 400 meters. Nest-site records: directly in the soil (1).

Nomenclature

 * . Rhytidoponera aquila Ward, 1984: 139, figs. 15, 16, 21, 22 (w.m.) NEW CALEDONIA.
 * Type-material: holotype worker, paratype workers, paratype males (numbers not stated).
 * Type-locality: holotype New Caledonia: 3 km. SW Touho, 400 m., 20°48’S, 165°13’E, 20.iv.1980, acc. no. 4074, nest in soil, rainforest (P.S. Ward); paratypes with same data but 270-400 m., acc. nos 4067, 4074, 4078 (P.S. Ward).
 * Type-depositories: ANIC (holotype); ANIC, BMNH, BPBM, MNHN, PSWC (paratypes).
 * [Misspelled as acquila by Taylor, 1987a: 71.]
 * Status as species: Taylor, 1987a: 71; Bolton, 1995b: 378.
 * Distribution: New Caledonia.

Description
Type Material

Holotype worker. New Caledonia: 3 km SW Touho, 400 m.    20. iv. 1980, nest in soil, rainforest (P.S. Ward acc. No. 4074) (ANIC Type No. 7579).

Paratype workers, males. A series of 3 accessions from 3 km SW Touho, 270-400 m. (P.S. Ward acc. Nos 4067, 4074, 4078) (ANIC, BPBM, BMNH, MNHN, PSW).

Measurements

Holotype worker. HW 1.54, WL 2.61, CI 0.87, MI 0.35, SI 1.20, SL12 0.07, SSC 17, FSC 15.

Paratype workers. HW 1.45-1.58, WL 2.50-2.68, CI 0.84-0.88, MI 0.32-0.37, SI 1.17-1.24, (n = 13) SL12 0.06-0.08, SSC 15-20, FSC 12-19 (n = 9).

Diagnosis of Worker

Anterior clypeal margin convex to weakly angulate. Frontal lobes expanded laterally to cover most of the antennal insertions. Frontal carinae convex and converging posteriorly to c. 3/4 of their maximum distance; the latter (FCD) c.2/5 of the head width (FCI 0.41-0.43). Head quadrate, longer than wide, the sides weakly convex, occipital margin weakly convex or flat. Eyes protruding slightly in dorsal view, OI 0.23-0.27. In lateral view, the median area of the frons rounds evenly into the vertex, and the occipital lobes are broadly rounded and non-protruding. Pronotum relatively slender, PI 0.74-0.79. Promesonotal suture distinct, evenly rounded in dorsal view. Mesopropodeal impression very weak, scarely evident in pronotal lateral view; basal and declivitous faces of the propodeum weakly differentiated. Inferior pronotal tooth distinct. Petiolar node as illustrated; robust (DNI 0.90-1.03), subrectangular, with a short anterior peduncle and poorly developed subpetiolar process (SL12 0.06-0.08).

Mandibles densely striate. Head longitudinally rugostriate, a fine striation overlying the coarse longitudinal rugae, inter-rugal punctures indistinct. Pronotum with obsolete rugae, overlaid by dense and weakly punctulate striation, showing a predominant longitudinal oreientation, at least on the posteromedial area of the pronotum. Remainder of mesosoma and petiolar node transversely striate to finely rugostriate. Abdominal tergites III and IV with dense, concentric, transverse striation and with weak, scattered punctures. On abdominal tergite IV the striae are concentric around a point located variably on the posterior half of the tergite, so that in dorsal view the posterior third of abdomina tergite IV is often longitudinally striate. Fine, erect seate common on most parts of body. Body violaceous-black, with finely scattered iridescence. Legs, mandibles, and antennae dark brown, the legs and antennae lighter apically,

References based on Global Ant Biodiversity Informatics

 * CSIRO Collection
 * Jennings J. T., L. Krogmann, and C. Burwell. 2013. Review of the hymenopteran fauna of New Caledonia with a checklist of species. Zootaxa 3736(1): 1-53.
 * Taylor R. W. 1987. A checklist of the ants of Australia, New Caledonia and New Zealand (Hymenoptera: Formicidae). CSIRO (Commonwealth Scientific and Industrial Research Organization) Division of Entomology Report 41: 1-92.
 * Ward P. S. 1984. A revision of the ant genus Rhytidoponera (Hymenoptera: Formicidae) in New Caledonia. Aust. J. Zool. 32: 131-175.
 * Ward P. S. 1985. Taxonomic congruence and disparity in an insular ant fauna: Rhytidoponera in New Caledonia. Systematic Zoology 34: 140-151.