Leptomyrmex unicolor

L. unicolor has been recorded in rainforest and wet sclerophyll. Nests occur in soil, in or under logs, and in leaf litter at base of live trees.

Identification
This species is restricted to the Australian Wet Tropics, where it can be easily distinguished from its sympatric congeners (Leptomyrmex rufipes, Leptomyrmex ruficeps and Leptomyrmex mjobergi) by its large body and broad head, which are covered with dense pubescence. The eyes are distinctly hairy, and the coloration is uniformly black, with contrasting white tarsi. (Lucky and Ward 2010)

Key to Australian Leptomyrmex Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Queens have yet to be collected.

Nomenclature

 *  unicolor. Leptomyrmex unicolor Emery, 1895g: 352, figs. 3, 4 (w.) AUSTRALIA. Wheeler, G.C. & Wheeler, J. 1951: 180 (l.); ; Lucky & Ward, 2010: 58 (m.). See also: Wheeler, W.M. 1915d: 261; Wheeler, W.M. 1934c: 108.

Worker
Lucky and Ward (2010) - measurements (n = 10) HL 1.79–1.99, HW 1.37–1.51, MFC 0.25–0.31, IOD 0.67–0.77, SL 3.54–3.91, EL 0.39–0.44, WL 3.27–3.73, PW 1.05–1.21, DPW 0.34–0.40, HTL 3.99–4.84, HTWmin 0.12–0.17, HTWmax 0.23–0.27, CI 0.72–0.80, SI 2.58–2.74, OI 0.08–0.10, HTC 0.45–0.70.

Large species (HL 1.79–1.99; HW 1.37–1.51) with broad head (, CI 0.72–0.80), excluding mandibles head width 3/4 of length. Head widest at eye level, sides of head broadly convex with concave genae. Postocular margin broadly rounded. Masticatory margin of mandible with approximately 7 large teeth interspersed with 10 denticles. Anterior clypeal margin concave. Eyes positioned posterior to midline of head, small, not surpassing margin of head. Pilosity on eyes distinct. Antennal scapes somewhat flattened, extending beyond posterior margin nearly 3/5 of their length.

Pronotum rather short, less than 1.5 times as long as broad. Dorsal face and declivity of propodeum subequal in length, dorsal face convex in profile, angle broadly rounded. Petiole narrow, with low rounded node, posterior and anterior slopes subequal, ventral surface of petiole feebly convex. Gaster slender, more than three times as long as broad. Legs slender, tibiae very slightly flattened.

Surface subopaque, finely and densely shagreened. Mandibles smooth and shining along apical borders and at tips, with a few coarse punctures. Pilosity mostly on clypeus, mandibles and venter, prominent black hairs on coxae, abundant minute oblique black hairs on scapes and legs. Eyes distinctly hairy. Body, femora and tibiae black, with bluish-green reflections. Mandibles and labium brownish yellow, antennal scapes black, with apical 1/4th brown. Metatarsi white, remaining tarsal joints, tibial spurs and funiculi yellowed.

Male
Lucky and Ward (2010) - HL 1.67–1.68, HW 1.03–1.09, SL 0.41–0.43, EL 0.69–0.71, HTL 3.98–4.07, CI 0.62–0.65, SI 0.39–0.40, SI2 1.07–1.08.