Leptomyrmex erythrocephalus

L. erythrocephalus has been recorded in wet sclerophyll, dry sclerophyll, rainforest, gallery rainforest and beach scrub. Nests occur in the ground, under rocks, in soil at the base of trees and under or in logs. (Lucky and Ward 2010)

Identification
Lucky and Ward (2010) – In the Sydney region, where L. erythrocephalus is sympatric with Leptomyrmex cnemidatus, the two species can be quite difficult to distinguish, but the following characters will aid in separating them: in L. erythrocephalus, the central portion of clypeus, excluding the anterior margin presents 0–2 black setae (2–4 in L. cnemidatus); if 2 setae are present then these are separated by 0.25 mm or more (< 0.25 mm in L. cnemidatus). Outside of the Sydney region geographic distribution can also help distinguish these species: L. erythrocephalus occurs coastally and inland from Victoria to the Sydney area, but farther north to the Queensland border it inhabits only inland areas (> 100km from the coastline), whereas L. cnemidatus populations remain within 100 km of the coast.

In color pattern L. erythrocephalus resembles Leptomyrmex ruficeps, but the latter is confined to northern Queensland. The rounded postocular margin also helps to distinguish L. erythrocephalus (elongate and constricted in L. ruficeps). L. erythrocephalus may be difficult to distinguish from some individuals of Leptomyrmex wiburdi, which possess the typical L. erythrocephalus color pattern. The large size (HW 1.31–1.47 mm; WL 4.20–4.64 mm; in L. wiburdi HW 1.15–1.33 mm; WL 3.06–3.65 mm), narrower head (CI 0.59–0.62 mm; in L. wiburdi CI 0.66–0.70) and longer scapes (SI 2.87–3.20; in L. wiburdi SI 2.29–2.64) will identify L. erythrocephalus upon close examination.

Identification Keys including this Taxon

 * Key to Australian Leptomyrmex Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Wheeler (1934) described queens of L. erythrocephalus as ergatoid, just slightly larger than workers.



Nomenclature

 *  erythrocephalus. Formica erythrocephala Fabricius, 1775: 391 (w.) AUSTRALIA. Emery, 1891a: 152 (m.); Wheeler, G.C. & Wheeler, J. 1951: 179 (l.); Imai, Crozier & Taylor, 1977: 345 (k.). Combination in Leptomyrmex: Mayr, 1862: 696. Senior synonym of clarki, froggatti, mandibularis, unctus: Lucky & Ward, 2010: 30. See also: Wheeler, W.M. 1915d: 265; Wheeler, W.M. 1934c: 85.
 * froggatti. Leptomyrmex froggatti Forel, 1910b: 57 (w.m.) AUSTRALIA. See also: Wheeler, W.M. 1934c: 101. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.
 * mandibularis. Leptomyrmex erythrocephalus var. mandibularis Wheeler, W.M. 1915d: 268 (w.) AUSTRALIA. Subspecies of erythrocephalus: Wheeler, W.M. 1934c: 87. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.
 * clarki. Leptomyrmex erythrocephalus subsp. clarki Wheeler, W.M. 1934c: 117 (w.) AUSTRALIA. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.
 * unctus. Leptomyrmex erythrocephalus subsp. unctus Wheeler, W.M. 1934c: 87 (w.) AUSTRALIA. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.

Description
Lucky and Ward (2010) – measurements (n = 10) HL 2.17–2.41, HW 1.31–1.47, MFC 0.27–0.32, IOD 0.78–0.93, SL 3.90–4.29, EL 0.41–0.50, WL 4.20–4.64, PW 1.21–1.44, DPW 0.44–0.56, HTL 4.80–5.38, HTWmin 0.13–0.17, HTWmax 0.27–0.32, CI 0.59–0.62, SI 2.87–3.20, OI 0.09–0.12, HTC 0.42–0.58.

As in Leptomyrmex cnemidatus, but larger on average: HW 1.31–1.47 mm; WL 4.20–4.64 mm (L. cnemidatus HW1.20–1.39 mm; WL 3.79–4.32 mm). Typical color pattern consisting of black body with contrasting rufotestaceous head, antennae and tarsi. In northern half of range (> 100km inland, e.g. Girraween NP) some individuals become variable in coloration, with head black and/or variable amounts of black and rufotestaceous color occuring on mesosoma.

Male
Lucky and Ward (2010) – measurements (n = 9) HL 1.60–1.80, HW 1.10–1.30, SL 0.56–0.64, EL 0.55–0.71, HTL 4.57–5.03, CI 0.65–0.76, SI 0.46–0.55, SI2 1.03–1.20. Emery’s (1891) description of the male of L. erythrocephalus is probably a misidentification, as it does not correspond with known males of this species.