Anochetus isolatus Mann

Shattuck, Steven O. & Slipinska, Ewa, 2012, Revision of the Australian species of the ant genus Anochetus (Hymenoptera: Formicidae), Zootaxa 3426, pp. 1-28 : 13-15

Anochetus isolatus Mann

( Fig. 9 )

Anochetus cato isolatus Mann, 1919: 302 (raised to species by Wilson, 1959: 508).

Anochetus rossi Donisthorpe, 1949: 747 (junior synonym of isolatus by Brown, 1978: 557). Anochetus splendens Karavaiev, 1925: 289 (junior synonym of isolatus by Brown, 1978: 557).

Types. Anochetus cato isolatus : Worker and male syntypes from "several small colonies" from Graciosa Bay , Santa Cruz Island, Solomon Islands ( MCZC, examined). Anochetus rossi: One worker and one queen syntype from Finschhafen , Papua New Guinea ( CASC, images examined). Anochetus splendens : Holotype queen from Wammar , Aru Island, Indonesia.

Diagnosis. The distinctive shape of the petiolar node, being drawn dorsally into a narrow, blunt point, will separate this species from all others in Australia. Additionally, the pronotum is relatively narrower and the eye relatively smaller than in most other Australian species.

Worker description. Sculpturing on front of head extending slightly beyond eyes. Scapes just reaching posterolateral corners ('lobes') of head; lacking or with a few short, inclined erect hairs. Pronotum and mesonotum smooth and shining. Dorsal surface of propodeum with transverse striations which extend laterally to the level of the spiracle and propodeal lobe. Propodeal angles rounded. Metanotal groove with coarse striations. Petiolar node drawn dorsally into a narrow point, lacking sculpture. Erect hairs on hind tibiae short, scattered and inclined. Colour dark brown, petiole, gaster and legs yellow to yellow-red, antennae, mandibles and posterior corners of head slightly lighter in colour than remainder of head capsule.

Measurements. Worker (n = 5): CI 86–90; EI 12–15; EL 0.15–0.20; HL 1.39–1.72; HW 1.25–1.49; HFL 1.14–1.38; ML 1.68–1.99; MandL 0.76–0.93; MTL 0.82–1.04; PronI 53–55; PronW 0.68–0.80; SL 1.09–1.29; SI 87–91.

Material examined. Australia: Queensland: Lockerbie, Cape York (Monteith, G.B.) ( ANIC); Torres Strait, Murray Is. ( Heatwole, H. & Cameron , E.) ( ANIC); Torres Strait, Saibai Island, nr. Saibai Village ( Heatwole, H. & Cameron , E.) ( ANIC). Papua New Guinea: New Britain: Valoka ( Noona Dan. Exp. 61–62) ( ANIC). Solomon Islands: Choiseul: Malangono (Greenslade, P.) ( ANIC); Guadalcanal: Marau (Greenslade, P.) ( ANIC); Mt. Austen (Greenslade, P.) ( ANIC); Rennell Is.: Niupani ( Noona Dan. Exp. 61–62) ( ANIC); San Cristobal: Wainoni Bay (Greenslade, P. J.M.) ( ANIC); Santa Cruz Islands: Nemoavill , Lua Lua distr. (Greenslade, P.) ( ANIC).

Comments. The concept of this species adopted here follows that developed by Brown (1978), noting that Brown left many questions concerning the taxonomy of this species and close relatives unanswered. The specific specimens included under Material Examined match each other very closely in sculpturing and show minimal variation in colour. However, a wide range of additional material is present in ANIC which varies from this pattern in the development of sculpturing and colour, most of which was outlined by Brown (1978). The true status of this and related species will require a detailed study of this additional material and extends beyond the scope of the current study.

This is a wide ranging species known from the Philippines south to the Solomon Islands and westward to the tip of Cape York Peninsula, Queensland. It is one of only two Australian Anochetus species which also occurs outside Australia. It is found in rainforest where it nests in rotten wood.

Figures

FIGURE 9. Anochetus isolatus (Torres Strait, Saibai Island, nr. Saibai Village, Queensland, ANIC 32 - 016928): A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.