Colobostruma australis

This species is most often found in wet sclerophyll and rainforests although in Western Australian it has been found in sandplain heath. Nests are generally in rotten wood or occasionally soil (Ants Down Under).

Identification
Shattuck (2000) - Among species in the froggatti-group australis can be recognised by the presence of a 6 (or rarely more) segmented antenna which lacks a subbasal lobe. As conceived here, this species shows considerable colour variation. This involves primarily the development of infuscation which varies from completely absent to well developed on the mesosoma, petiole and postpetiole and to a lesser extent the head and gaster. However, the variation in this character is so great that it is of little value in recognising subsets of specimens and is thus considered here to represent intraspecific variation.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  australis. Colobostruma australis Brown, 1959c: 4, fig. 3 (w.q.m.) AUSTRALIA. See also: Shattuck, in Bolton, 2000: 41.

Worker
Shattuck (2000) - TL 2.6 - 3.2, HL 0.68 - 0.76, HW 0.58 - 0.69, CI 85 - 91, ML 0.17 - 0.19, MI 22 - 26, SL 0.34 - 0.40, SI 56 - 59, PW 0.35 - 0.44, AL 0.74 - 0.89 (6 measured). Anterior region of head rounding gradually from the dorsal to lateral surfaces, not phragmotic. Ridge immediately in front of eye reduced, weakly defined. Frontal lobes and lateral margins of clypeus smooth relative to the surrounding surface of the head. Mandibles broadly triangular. Hairs absent from dorsum of head. Posterior margin of head deeply concave. Antenna with 6, or rarely more, segments. Scape elbowed and lacking a subbasal lobe. Pronotum lacking anterolateral angles. Propodeum high, its posterior face approximately the same height as the petiolar node and with broad, thin lamellae; in profile the dorsum of the mesosoma weakly convex with a weak concavity at the metanotal groove. Lateral postpetiole drawn outwards into thin flange-like wings, the wings with translucent windows along their posterior margins only. First gastral tergite smooth, superimposed with low, closely spaced carinae on the anterior one-quarter. Body colour honey yellow, generally with varying amounts of infuscation on the dorsum of the head, dorsal and lateral surfaces of the mesosoma, petiole, postpetiole and dorsum of the gaster. In extreme cases the majority of the mesosoma, petiole and postpetiole are dark red-black.

Additional References

 * Shattuck, S. O. 2000. Genus Colobostruma. Genus Mesostruma. Genus Epopostruma. Pp. 31-67 in: Bolton, B. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028.