Leptomyrmex geniculatus

Collected in rainforest and dry forest but its nesting habits are unknown.

Identification
The distinctive color pattern that distinguishes Leptomyrmex geniculatus from its two New Caledonian congeners is the combination of dark gaster and dark distal portions of the femora on an otherwise orange body. In some specimens the pronotum may also be dark. Aside from these color differences, this species greatly resembles Leptomyrmex pallens and Leptomyrmex nigriceps. There are scattered records of this species throughout the island, where it has been found in sympatry with L. pallens. This species appears to be less commonly encountered than L. pallens. (Lucky and Ward 2010)

Key to New Caledonian Leptomyrmex Species

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

Castes
Queen and male unknown.

Nomenclature

 *  geniculatus. Leptomyrmex pallens var. geniculata Emery, 1914f: 418 (w.) NEW CALEDONIA. Subspecies of pallens: Wheeler, W.M. 1934c: 109. Raised to species: Lucky & Ward, 2010: 36.

Worker
Lucky and Ward (2010) – measurements (n = 7) HL 1.80–1.95, HW 0.99–1.10, MFC 0.22–0.26, IOD 0.55–0.61, SL 3.36–3.81, EL 0.33–0.38, WL 3.21–3.52, PW 0.86–0.94, DPW 0.40–0.43, HTL 3.80–4.17, HTWmin 0.10–0.15, HTWmax 0.17–0.19, CI 0.54–0.57, SI 3.39–3.63, OI 0.09–0.11, HTC 0.61–0.85.

L. geniculatus is a small species (HW 0.99–1.10 mm; WL 3.21–3.52 mm) with elongate head nearly twice as long as broad, excluding mandibles (CI 0.54–0.57). Sides of head parallel, slightly convex, posterior to eyes head narrowing gently to flat postocular margin. Approximately 15 teeth and denticles interspersed on masticatory margin of mandible. Anterior clypeal margin flat to weakly concave. Eyes positioned approximately at midline of head, relatively large, convex, hairless, not reaching the lateral margins of head. Antennae extremely slender, but not compressed. Scapes extending past the posterior margin by 2/3 their length.

Pronotum elongate. Propodeum short, dorsal face about 1.5 times as long as the convex declivitous face, angle rounded. Dorsal face of propodeum convex, with a transverse impression at the anterior end. Petiolar node small, triangular in profile with a rounded dorsum. Anterior, dorsal and posterior face of petiole with longitudinal impression posterior face longer than anterior, ventral surface flat. Gaster broadly elliptical. Legs very slender, not compressed (HTC 0.61–0.85).

Surface finely and densely shagreened, slightly shining. Mandibles with a single row of coarse punctures along margin. Pubescence white, extremely fine standing hairs scarce, confined to clypeus, venter and gaster. Body mostly pale rufotestaceous, with first two segments of gaster and distal 1/2 to 1/3 of femora black. Head and sometimes pronotum slightly darker than body.

Type Material
Lucky and Ward (2010) – Syntypes, 2 workers, New Caledonia: Coula-Boréaré (Sarasin & Roux) ; syntypes, 2 workers, New Caledonia: Tchalabel (Sarasin & Roux) MSNG; also 1 syntype worker, New Caledonia: "New Caledonia". One worker from Coula-Boréaré here designated lectotype (CASENT0127391).

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
 * CSIRO Collection
 * Emery, C. 1914. Les fourmis de la Nouvelle-Calédonie et des îles Loyalty. Nova Caledonia. A. Zoologie 1:393-437.
 * 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.
 * Lucky A., and P. S. Ward. 2010. Taxonomic revision of the ant genus Leptomyrmex Mayr (Hymenoptera: Formicidae). Zootaxa 2688: 1-67.
 * Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.
 * 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.
 * Wheeler W. M. 1915. The Australian honey-ants of the genus Leptomyrmex Mayr. Proceedings of the American Academy of Arts and Sciences 51: 255-286.
 * Wheeler W. M. 1934. A second revision of the ants of the genus Leptomyrmex Mayr. Bulletin of the Museum of Comparative Zoology 77: 69-118.
 * Wheeler W.M. 1935. Check list of the ants of Oceania. Occasional Papers of the Bernice Pauahi Bishop Museum 11(11):1-56.
 * Wheeler, W. M. 1927. The ants of Lord Howe Island and Norfolk Island. Proc. Am. Acad. Arts Sci. 62: 121-153