Notoncus gilberti

This is the only species of Notoncus known to occur outside Australia.

Identification

 * Scutellum in the form of a thick, rounded tumulus or oval process.
 * Propodeum at most very finely and superficially sculptured, essentially smooth and shiny; dorsum of gaster with only extremely sparse punctulation and appressed pubescence; mandibles very finely striate over most of dorsal surfaces (less so near insertions).

Heterick (2009) - This species has cornicles on the humeral angles, and the metanotum, which is posteriorly lobate, is raised above the level of the propodeum.

Distribution
Heterick (2009) - Found in wetter parts of the south-west (WA), but its more general range also includes NSW and Qld.

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

Biology
Heterick (2009) - Abundant in and around Perth, and quite commonly colonises suburban gardens. Here, small granules of soil heaped into amorphous clumps are often the only sign of its presence during the day, as the ant is usually a nocturnal forager.

Wheeler (1934) collected workers and a female from a nest under stones.

Nomenclature

 *  gilberti. Notoncus gilberti Forel, 1895f: 418 (w.q.) AUSTRALIA. Senior synonym of annectens, gracilior, politus and material of the unavailable name manni referred here: Brown, 1955d: 490.
 * gracilior. Notoncus gilberti var. gracilior Forel, 1907h: 299 (w.) AUSTRALIA. Junior synonym of gilberti: Brown, 1955d: 490. See also: Wheeler, W.M. 1934d: 153.
 * politus. Notoncus politus Viehmeyer, 1925a: 38 (w.q.) AUSTRALIA. Junior synonym of gilberti: Brown, 1955d: 490.
 * annectens. Notoncus gilberti subsp. annectens Wheeler, W.M. 1934d: 154 (w.) AUSTRALIA. Junior synonym of gilberti: Brown, 1955d: 490.

Description
Wheeler (1934) - Length 3-4 mm.

Head slightly longer than broad, subrectangular very nearly as broad in front as behind, with straight posterior border and slightly convex sides. Eyes feebly convex, their anterior orbits at the median transverse diameter of the head; ocelli minute, rather widely seperated. Mandibles stout, with convex external borders, their masticatory borders with six teeth, all stout, except the third from the tip, which is minute. Clypeus convex and carinate in the middle, its anterior border broadly rounded and feebly and rather broadly sinuate in the middle. Antennal scapes extending fully twice their :greatest diameter beyond the posterior corners of the head; first funicular joint as long as 2 and 3 together, joints 2-10 nearly one and one-half times as long as broad, terminal joint slightly shorter than the two preceding -together. Pronotum without the neck more than twice as broad as long, produced on each side as a broad, blunt, subtriangular protuberance; mesometanotum in profile straight and horizontal, interrupted by the impressed mesometanotal suture; mesonotum from above broadly elliptical, truncated posteriorly, longer than broad; metanotum semicircular; metaepinotal incision deep, overhung by the posterior, swollen end of the metanotum; epinotum .small and low, concave and sloping in the middle, on each side with a strong, thick, rounded, longitudinal thickening or welt so that in profile the base seems to be convex and horizontal, shorter than the abrupt, concave declivity. Petiole less than twice as high as long, the scale in profile cuneate, the anterior and posterior surfaces convex, the apex more compressed and narrowed, the superior border acute and broadly excised. Gaster elliptical. Legs moderately long.

Shining; mandibles finely and superficially striate, very sparsely punctate; clypeus, cheeks and front nearly as far back; as the anterior ocellus sharply, longitudinally striate; frontal area' and remainder of head smooth and shining, the latter very sparsely punctulate; thorax very smooth and shining, except the neck and extreme anterior border of the mesonotum, which are transversely, and the pleural which are in places indistinctly, longitudinally striate. Petiole and gaster smooth and shining, sparsely punctulate; legs more shagreened, with coarser, piligerous punctures, antennal scapes very finely granular, subopaque.

Hairs yellowish, bristly, very sparse, erect and of uneven length on the body and scapes; more numerous and oblique on the legs; pubescence fine and appressed, present only on the scapes, middle and hind coxal; gaster with some appressed and very short hairs.

Brownish red, gaster blackish or dark brown; femora, tibial and in some specimens also the thorax and posterior portion of the head infuscated; thoracic sutures, trochanters, knees, tarsi and posterior borders of gastric segments yellowish; mandibles, except the teeth, which are black, clypeus and cheeks yellow.

References based on Global Ant Biodiversity Informatics

 * Brown W. L., Jr. 1955. A revision of the Australian ant genus Notoncus Emery, with notes on the other genera of Melophorini. Bulletin of the Museum of Comparative Zoology 113: 471-494.
 * Taylor R. W. 1987. A checklist of the ants of Australia, New Caledonia and New Zealand (Hymenoptera: Formicidae). CSIRO (Commonwealth Scientific and Industrial Research Organization) Division of Entomology Report 41: 1-92.
 * Taylor R. W. 1992. Nomenclature and distribution of some Australian and New Guinean ants of the subfamily Formicinae (Hymenoptera: Formicidae). Journal of the Australian Entomological Society 31: 57-69.
 * Wheeler W. M. 1934. Contributions to the fauna of Rottnest Island, Western Australia. No. IX. The ants. Journal of the Royal Society of Western Australia 20: 137-163.