Rhytidoponera wilsoni

This species forages during the daylight hours on foliage and over rocks on the forest floor.

Identification
Holotype [MCZ] a stray diurnal forager taken on foliage at 180-400 m. on Mt. Mou, north of Paita, New Caledonia (E.O. Wilson leg., XII-10-1954, No. 110). Paratype workers were taken with the holotype and at Le Chapeau Gendarme, east of Yahoue, and at Ciu, near Mt. Canala (Wilson Nos. 73, 74, 80, 96 and without numbers). These were taken foraging during the daylight hours on foliage and over rocks on the forest floor. One nest was found beneath a stone; other workers came from leaf litter berlesates. The Ciu sample was very dark, and had the legs dark brown. The occipital border varied in degree of concavity. Paratypes in MCZ, USNM and elsewhere.

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

Specimens have been collected by G.B. Monteith from dung traps (#11094) at Yahoue, 90 meters elevation, 3-4 November 2002,.

Biology
These were taken foraging during the daylight hours on foliage and over rocks on the forest floor. One nest was found beneath a stone; other workers came from leaf litter berlesates.

Nomenclature

 * . Rhytidoponera wilsoni Brown, 1958g: 294, fig. 38 (w.) NEW CALEDONIA.
 * Type-material: holotype worker, paratype workers (number not stated).
 * Type-locality: holotype New Caledonia: Mt Mou, N Paita, 180-400 m., 10.xii.1954, acc. 110, on foliage (E.O. Wilson); paratypes with same data, and New Caledonia: Le Chapeau Gendarme, E Yahoué (E.O. Wilson), New Caledonia: Ciu, nr Mt Canala (E.O. Wilson).
 * [Note: accessions numbers of paratypes are 73, 74, 80, 84, 96; the text does not indicate which numbers are associated with which specimens.]
 * Type-depositories: MCZC (holotype); MCZC, USNM (paratypes).
 * Status as species: Ward, 1984: 150 (redescription); Taylor, 1987a: 72; Bolton, 1995b: 381.
 * Distribution: New Caledonia.

Description
Holotype worker: TL 5.2, HL 1.25, HW (excluding eyes) 1.06 (CI 87) WL 1.73, scape L 1.12, max. diameter eye 0.26 mm. Very similar to Rhytidoponera numeensis, from which it differs principally in have a notably more strongly anteroposteriorly compressed node, with a different petiolar process; the posterior face of the node is concave as seen from the side. The head of wilsoni has a more broadly concave occipital margin (straighter in some views) and slightly more sharply rounded occipital corners than in numeensis. The sculpture differs in several details; generally speaking, the punctures are coarser and more closely contiguous over head, alitrunk and gaster, and the ridges between tend to form coarse, rather indefinite rugules (longitudinal on head, diagonal on sides of alitrunk, transverse on propodeum and anterior face of petiolar node) in place of the fine, dense striation of these same areas in numeensis. Postpetiole rather finely arched-striate, passing into a posteromedian area of finer, concentric striae that are interrupted by and interspersed with fine, indistinct punctulation. Coarse piligerous punctures of this segment very shallow, indistinct, and not so clearly elongate as the corresponding ones in numeensis. Second gastric segment very finely and densely striate, the pattern arched over a posteromedian weakly shining area of very superficial elliptical-concentric striation (longitudinal axis) that is very finely interrupted or coriaceous (clearcut, uniform, and predominantly longitudinal striation in numeensis). Coarse piligerous punctures of this segment small and inconspicuous, much smaller than the corresponding ones of numeensis.

Erect pilosity and appressed pubescence fairly abundant but not dense, uneven in length, the pubescence conspicuous at all only on the gaster and appendages. Color piceous, the head, petiole and gaster ligher and a bit more reddish than the alitrunk. To the naked eye, the body appears very dark, nearly or quite black. Legs, mandibles and antennae orange-brown. Coloration in general much like that of numeensis.

References based on Global Ant Biodiversity Informatics

 * Berman M., A. N. Andersen, C. Hé ly, and C. Gaucherel. 2013. Overview of the distribution, habitat association and impact of exotic ants on native ant communities in New Caledonia. PLoS ONE 8(6): e67245. doi:10.1371/journal.pone.0067245
 * Brown W. L., Jr. 1958. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bull. Mus. Comp. Zool. 118: 173-362.
 * 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.