Tetraponera punctulata

While the ant will nest in dead branches of trees of several genera, it favours eucalypts, and is known to tend Coccoidea (Ward 2001). Within the SWBP, T. punctulata is widespread and reasonably common, and can  typically be seen foraging around the trunk of Wandoos. The unusually long, thin outline of this species makes it readily recognizable in the field. (Heterick 2009)

Identification
Ward (2001) - In common with other members of the T. laeviceps-complex, the worker caste of T. punctulata has an enclosed, pit-shaped mesopropodeal impression. T. punctulata workers can be distinguished from those of related species by the following features: (1) most punctures on head relatively small (typically about 0.010 mm in diameter), separated by several diameters, and contrasting with the coarser, denser punctures on the pronotum; (2) in profile dorsal face of propodeum more or less flattened or occasionally elevated posteriorly, but not depressed posteriorly; (3) posterior half of petiolar sternite strongly protruding ventrally; and ( 4) petiole relatively broad (PWI 0.50-0.70). In addition, the eyes are of moderate size (REL 0.30--0.39); appressed pubescence is rather dense on the body, especially on the postpetiole and gaster; and the petiolar node, while variable in shape, always has the posterior face descending gently rather than steeply from the rounded summit. Queens and males can be recognised by the features listed in the keys. Although there are apparently no surviving types of T. punctulata, the original description and the type locality leave little doubt about the application of this name.

Workers of T. punctulata show rather extensive and complex patterns of morphological variation. Body size varies considerably, even within populations. At some localities in north Queensland and Northern Territory it is possible to distinguish nest series containing either large (HW- 1.10 mm) or small (HW- 0.90 mm) workers, each occupying different Eucalyptus trees. The larger workers tend to have disproportionately smaller eyes, more elongate heads, and more robust petiolar nodes, but these differences appear to be due to allometric effects.

Head shape also varies geographically. In northern Queensland some T. punctulata workers have the propodeum conspicuously elevated, yielding atypically high PDI values (PDI > 1.1 0). The shape of the petiolar node varies continuously from rather long and slender to short and robust, with the most robust petioles (those with the highest PLI values) occurring in workers from northwestern Australia. Body pilosity ranges from sparse to common, as reflected in the range of CSC and MSC values, without showing any marked geographical tendencies. Standing hairs are always uncommon on the upper half of the head and on the mesonotum. Finally, there is variation in the density and size of the punctures on the head and mesosoma, and in the texture of the interspaces. As a result of weaker background sculpture (i.e. interspaces tending to be smooth and shiny), the sheen of the integument is generally stronger in eastern coastal populations, when compared with samples from drier inland localities.

Distribution
Ward (2001) - Tetraponera punctulata is the most wide-ranging species of Tetraponera in Australia, occurring across much of the continent except the far south and parts of the arid interior. Isolated populations occur in the Flinders Ranges of South Australia and in the MacDonnell Ranges of central Australia. In MHNG there is an old worker from “Geelong, Viktoria” (leg. Davey), but I suspect that this has been mislabeled. There are no contemporary locality records anywhere near the state of Victoria. Outside Australia T. punctulata is known from a number of sites in southern Papua New Guinea.

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

Biology
Ward (2001) - Most localities from which T. punctulata has been recorded are in Eucalyptus woodland or open forest. In the more northern parts of Australia and in savannas near Port Moresby, Papua New Guinea, workers are often seen foraging on the trunks of Eucalyptus trees, and nests occur in dead branches in the canopy of the same trees. Specific nest site records include dead branches of E. alba, E. camaldulensis, E. dichromophloia, E. maculata, and E. papuana. Other habitat records include riparian woodland (Western Australia), monsoon gully forest (Northern Territory), mangrove (Northern Territory, Queensland), rainforest (Queensland, Papua New Guinea), gallery rainforest (Queensland), urban parkland (Queensland, Papua New Guinea), and littoral vegetation (Queensland). Nest site records from these other habitats include dead twigs or branches of Avicennia eucalyptifolia, Calophyllum inophyllum, and Rhizophora sp.

Tetraponera punctulata is able to occupy large dead branches, often composed of rather hard wood, by taking advantage of cavities previously excavated by coleopteran and lepidopteran larvae. I have twice encountered colonies whose galleries extended into live wood and in both instances the workers were tending coccids in the nest. One such nest was in branches of Eucalyptus camaldulensis (47 km S Derby, Western Australia) with scales of the genus Myzolecanium. The second record was from a live, beetle-bored branch of Avicennia eucalyptifolia (Scraggy Point, Hitchinbrook I., Queensland), with scales identified as ?Coccus sp. These observations point to the kind of biology that might characterise transitions from generalist nesting habits to specialised ant-plant inhabitation (Ward 1991).

Nomenclature

 *  punctulata. Tetraponera punctulata Smith, F. 1877b: 72 (q.) AUSTRALIA. Combination in Sima: Dalla Torre, 1893: 55; in S. (Tetraponera): Emery, 1921f: 26; in Tetraponera: Chapman & Capco, 1951: 81. Senior synonym of kimberleyensis: Ward, 2001: 641.
 * kimberleyensis. Sima punctulata var. kimberleyensis Forel, 1915b: 37 (w.) AUSTRALIA. Combination in S. (Tetraponera): Emery, 1921f: 26; in Tetraponera: Taylor & Brown, D.R. 1985: 18. Junior synonym of punctulata: Ward, 2001: 641.

Worker
Ward (2001) - HW 0.77-1.44, HL 0.95-1.69, LHT 0.69-1.12, CI 0.69-0.88, FCI 0.13-0.18, REL 0.30-0.39, REL2 0.37-0.48, SI 0.46-0.62, SI3 1.12-1.54, FI 0.43-0.53, PLI 0.57-0.78, PWI 0.50-0.70, PDI 1.00-1.19, LHT/HW 0.80-0.85, CSC 0-5, MSC 0-22.

Medium- to large-sized species; head ranging from moderately broad to somewhat elongate (see CI values); clypeus relatively short, its anteromedial margin broadly convex and protruding beyond level of anterolateral margins, often weakly crenulate; distance between frontal carinae approximately equal to, or slightly exceeding, maximum scape width; eye relatively small (REL <0.40; REL2 usually <0.46); scape length exceeding eye length, often strongly so (SI3 usually> 1.20); profemur moderately robust (see range ofFI values); pronotum relatively slender, lacking strong lateral expansion (PrWM/MTW 1.04-1.25); lateral pronotal margins well developed, blunt-edged; mesopropodeal impression with a transverse, pit-shaped depression, flanked by lateral ridges; propodeum as high as, or higher than, wide (see PDI values); dorsal face of propodeum usually somewhat flattened in profile and rounding into the steep declivitous face, occasionally the propodeum more strikingly elevated; petiole with distinctly differentiated anterior peduncle and node, the posterior face of node gently inclined towards the rounded summit, the anterior face a little steeper; posterior half of petiolar sternite with prominent ventral protrusion; petiole variable in height and width (see range of PLI and PWI values), although never more than twice as long as wide; postpetiole varying from about 1.2x wider than long to slightly longer than wide; metabasitarsal sulcus well developed, lying in a darkened patch of cuticle adjacent to a slight carina and occupying about one half to two thirds the length ofthe basi tarsus. Integument with numerous small punctures, the interspaces varying from smooth and shiny to finely reticulate and sublucid; punctures on dorsum of head mostly about 0.010 mm in diameter and separated by more than their diameters; punctures on dorsum of mesosoma and petiole tending to be coarser and denser, those on pronotum about 0.015 mm in diameter and often separated by no more than their diameters; side of mesosoma partly smooth and shiny anteriorly (especially on side of pronotum), becoming increasingly punctate or reticulopunctate posteriorly; postpetiole and gaster puncticulate, sublucid; malar area rugulopunctate. Standing pilosity varying from sparse to moderately common (see CSC and MSC values), present on gaster and apex of head, and on the dorsal surfaces ofthe following: upper half of head (0-5), pronotum (0-9), mesonotum (0-3), propodeum (0-17), petiole (0-7) and postpetiole (0-8); appressed pubescence common on most of body, especially dense on postpetiole and gastric tergites. Black to dark brownish-black; mandibles, antennae, tarsi and sometimes one or more tibiae lighter, varying from medium-brown to yellowish-brown.

Type Material
Ward (2001) - Syntype(s), queen(s), Champion Bay, Western Australia [type(s) apparently lost].