Leptomyrmex wiburdi

L. wiburdi has been recorded in rainforest, wet sclerophyll and dry sclerophyll. Nests occur in soil, in standing or fallen trees or snags, in stumps, and under rocks.

Identification
This species can be distinguished by its broad head, which is widest posterior of the eyes, short scapes and generally small size. L. wiburdi can be easily mistaken for Leptomyrmex cnemidatus or Leptomyrmex erythrocephalus, as the general body shape and round postocular portion of the head are similar amongst these three species which co-occur in New South Wales. There is no ‘typical’ color pattern that characterizes L. wiburdi workers, rather they take on a variety of color patterns, including the typical patterns seen in L. cnemidatus and L. erythrocephalus; workers with different color forms have even been observed in a single nest. Many individuals possess mottled brown-black coloration on the head and mesosoma, which is not seen in either L. cnemidatus or L. erythrocephalus. L. wiburdi workers evidently mimic workers of co-occurring species of Leptomyrmex. (Lucky and Ward 2010)

Key to Australian Leptomyrmex Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 * pictus. Leptomyrmex wiburdi var. pictus Wheeler, W.M. 1915d: 273 (w.) AUSTRALIA. Wheeler, G.C. & Wheeler, J. 1966: 728 (l.). Subspecies of wiburdi: Wheeler, W.M. 1934c: 101. Junior synonym of wiburdi: Lucky & Ward, 2010: 60.
 *  wiburdi. Leptomyrmex wiburdi Wheeler, W.M. 1915d: 272, fig. 7 (w.) AUSTRALIA. Wheeler, W.M. 1934c: 99 (m.); ; Lucky & Ward, 2010: 61 (ergatoid q.). Senior synonym of pictus: Lucky & Ward, 2010: 60.

Worker
Lucky and Ward (2010) - measurements (n = 12)HL 1.65–1.94, HW 1.15–1.33, MFC 0.27–0.36, IOD 0.70–0.86, SL 2.74–3.3, EL 0.36–0.45, WL 3.06–3.65, PW 0.94–1.15, DPW 0.30–0.43, HTL 3.32–3.88, HTWmin 0.13–0.17, HTWmax 0.22–0.26, CI 0.66–0.70, SI 2.29–2.64, OI 0.09–0.12, HTC 0.56–0.69.

Relatively small species (HL 1.65–1.94; HW 1.15–1.33) with broad head (CI 0.66–0.70), excluding mandibles head width more than 3/5 of length. Head widest posterior to eyes, sides of head straight, narrowing anteriorly, genae slightly concave. Beyond eyes head broadly and distinctly rounding into posterior margin. Masticatory margin of mandible with approximately 20 teeth and denticles interspersed. Anterior clypeal margin medially concave. Eyes positioned posteriorly to midline of head, relatively large, hairless, not surpassing margins of head. Antennal scapes relatively short, not compressed, surpassing posterior margin of the head by less than 2/3 their length.

Pronotum stout, very convex. Dorsal face of propodeum more than twice as long as declivity, angle joining the two very broadly rounded. Propodeum with distinct transverse impression at anterior end. Petiole triangular in profile, dorsum with medial longitudinal impression, anterior face not much longer than posterior face, ventral suface of petiole distinctly projecting. Gaster elliptica''L. Legs relatively short, tibiae distinctly compressed.

Surface subopaque, very finely and densely shagreened. Mandibles slightly shining, coarsely punctate along apical border. Pubescence extremely fine, giving the body a pruinose appearance. Hairs few, confined to clypeus, mandibles and venter.

Coloration extremely variable; ranging from erythrocephalus-like to rufipes-like coloration, with many intermediate states apparently co-occurring. A common color pattern presents a rufotestaceous head obfuscated toward the postocular margin, mottled dark brown to black mesosoma and legs with joints and sutures pale, black gaster, and mandibles, antennae and tarsi rufotestaceous.

Queen
Lucky and Ward (2010) – Head broader than in worker. Three ocelli deeply set into head in triangular formation, the anteriormost one largest, the posterior two smaller. Pronotum, mesonotum and propodeum voluminous, convex. The anterior portion of the mesonotum with a slight medial bump. Dorsal face of propodeum raised, convex. Petiole broader than high. Gaster globose, larger than in worker. Scapes, femora and tibiae broad, robust. Surface of body appearing dusty, shagreened.

Male
Lucky and Ward (2010) – measurements (n = 4) HL 1.39–1.48, HW 1.09–1.15, SL 0.48–0.54, EL 0.54–0.61, HTL 3.14–3.42, CI 0.76–0.81, SI 0.42–0.49, SI2 1.10–1.33.