Leptomyrmex ruficeps

Leptomyrmex ruficeps has been recorded mostly in rainforest, with one record from Eucalyptus open forest. Nests occur in cavities in live trees, on the ground at tree bases, in or under logs, and under rocks.

Identification
This species is restricted to the Australian Wet Tropics, where it can be easily distinguished from its sympatric congeners (Leptomyrmex rufipes, Leptomyrmex unicolor and Leptomyrmex mjobergi) by the neck-like constriction of the posterior margin of the head, and its distinctive coloration: black body with red head and antennae. This species is more slender than L. unicolor and larger than L. mjobergi. With the exception of coloration, this species closely resembles its sister species, L. rufipes, which is red with a black gaster. (Lucky and Ward 2010)

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Queens have yet to be collected.

Nomenclature

 *  ruficeps. Leptomyrmex varians var. ruficeps Emery, 1895g: 352 (w.) AUSTRALIA. Forel, 1915b: 84 (m.); Wheeler, W.M. 1915d: 261 (l.). Subspecies of varians: Wheeler, W.M. 1934c: 102. Raised to species: Lucky & Ward, 2010: 48.

Worker
Lucky and Ward (2010) – HL 2.15–2.41, HW 1.16–1.47, MFC 0.24–0.29, IOD 0.64–0.74, SL 3.70–4.38, EL 0.38–0.51, WL 3.98–4.28, PW 1.02–1.12, DPW 0.41–0.48, HTL 4.90–5.60, HTWmin 0.13–0.17, HTWmax 0.18–0.24, CI 0.53–0.61, SI 2.83–3.64, OI 0.10–0.12, HTC 0.64–0.81.

As in Leptomyrmex rufipes: medium sized species with head long and slender, excluding mandibles nearly twice as long as broad. Head widest at eye level, sides of head subparallel, narrowing anteriorly, genae slightly concave. Beyond eyes narrowing abruptly to dorsoventrally flattened and posteriorly projecting neck-like constriction at posterior margin. Masticatory margin of mandible with 15 to 20 teeth and denticles interspersed. Anterior clypeal margin flat to weakly concave. Eyes positioned approximately at midline of head, eyes small, convex, hairless, not reaching lateral margins. Antennae long and slender, not compressed, scapes surpassing posterior margin of head by 2/3 their length.

Pronotum slender, elongate. Propodeum short, dorsal face of propodeum with transverse impression at anterior end, declivitous face short and convex, propodeal angle very rounded. Petiole triangular in profile, posterior face with median longitudinal impression, dorsum rounded, posterior face longer than anterior face. Ventral surface of petiole nearly flat. Gaster elongate-elliptica''L. Legs very long and slender, not compressed.

Surface very finely shagreened and somewhat shining throughout. Mandibles with a coarse row of punctures along margin. Pubescence pale, sparse. Hairs minimal, confined to clypeus, venter and gaster. Body black with red head and antennae. Tarsi and tibiae yellow, gaster entirely black with anal orifice pale yellow.

Male
Lucky and Ward (2010) – HL 1.86–1.94, HW 1.30–1.35, SL 0.51–0.57, EL 0.68–0.70, HTL 4.68–4.89, CI 0.67–0.71, SI 0.39–0.42, SI2 0.85–0.89.

Type Material
Lucky and Ward (2010) - Type material examined: Syntypes, 5 workers, Australia, Queensland: Mt. Bellendenker (Podenzana)