Leptomyrmex puberulus

L. puberulus has been recorded in secondary and primary rainforest. Nests occur in soil and in logs.

Identification
Leptomyrmex puberulus is distinctive among all the New Guinea species for having short standing hairs on the eyes.This species most closely resembles Leptomyrmex flavitarsus, the other species in New Guinea with dense pubescence on the body. Generally, L. puberulus is uniformly pale yellow, but some forms are darker yellow, approaching brown. L. flavitarsus is very dark brown, approaching black. A stouter head and shorter appendages (HW 1.02–1.20 mm; SI 2.77–3.64; HTL 3.33–3.86) distinguishes L. puberulus from the similarly pale Leptomyrmex fragilis, which is more gracile, with longer appendages (HW 0.94–1.05 mm; SI 3.92–4.73; HTL 4.41–5.02). (Lucky and Ward 2010)

Key to New Guinean Leptomyrmex Species

Distribution based on Regional Taxon Lists
Indo-Australian Region: Papua New Guinea.

Nomenclature

 *  puberulus. Leptomyrmex puberulus Wheeler, W.M. 1934c: 112, fig. 14 (w.) NEW GUINEA. Lucky & Ward, 2010: 46 (m.).

Worker
Lucky and Ward (2010) - measurements (n = 10) HL 1.63–1.83, HW 1.02–1.20, MFC 0.21–0.26, IOD 0.58–0.68, SL 3.08–3.75, EL 0.33–0.42, WL 2.99–3.29, PW 0.84–0.95, DPW 0.30–0.37, HTL 3.33–3.86, HTWmin 0.10–0.16, HTWmax 0.14–0.18, CI 0.61–0.66, SI 2.77–3.64, OI 0.12–0.16, HTC 0.63–0.96.

Smaller species (HW 1.02–1.20 mm; WL 2.99–3.29 mm) with head less than twice as long as broad, excluding mandibles (CI 0.61–0.66). Head widest at eyes, sides of head slightly convex, genae feebly concave anteriorly. Behind the eyes, sides of head gently rounding to flat postocular margin. Masticatory margin of mandible with approximately 15 teeth and denticles. Anterior clypeal margin weakly convex. Eyes positioned at midline of head, small and nearly circular, convex and distinctly hairy, reaching margins of head. Antennal scapes long and slender.

Dorsal face of propodeum with transverse impression at anterior end. Dorsal face slightly longer than convex declivitous face. Dorsal and declivitous faces meeting at rounded angle. Petiole triangular in profile, with rounded dorsum bearing deep longitudinal impression; ventral surface flat. Gaster narrow. Legs long and slender, slightly compressed (HTC 0.63–0.96 mm).

Surface very finely and superficially shagreened, less shining. Pubescence grey, long and abundant on all parts of the body and appendages, especially on the head, pronotum and gaster. Erect hairs present on the clypeus, venter and gaster. Body ranging from pale yellow to dark yellowish-brown. Tarsi nearly white. Some individuals with gaster darker than the rest of the body.

Male
Lucky and Ward (2010) – measurements (n = 2) HL 1.51, HW 0.76–0.77, SL 0.77–0.81, EL 0.46–0.50, HTL 4.48–4.55, CI 0.50–0.51, SI 1.01–1.05, SI2 0.49.

Type Material
Lucky and Ward (2010) - Type material examined: Syntypes, 5 workers, Papua New Guinea: ‘Morobe District’ (Stevens)