Polyrhachis weiri

Polyrhachis weiri is apparently restricted to the extreme north of the Northern Territory, including its adjacent islands, and to the Kimberley region of Western Australia. Nothing is known about the species’ biology, but as the type series specimens were collected foraging on the ground it is reasonable to suggest that their nesting habit is terrestrial or subterranean.

Identification
Polyrhachis weiri is characterised by the strongly posteriorly converging lateral margins of the promesonotum (PMI ca. 250).

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Known only from the worker caste.

Nomenclature

 *  weiri. Polyrhachis (Hagiomyrma) weiri Kohout, 2013: 551, figs. 10A-B (w.) AUSTRALIA.

Worker
(holotype cited first): TL c. 6.85, 5.59-7.36; HL 1.75, 1.40- 1.78; HW 1.34, 1.06-1.34; CI 76, 74-76; SL 2.09, 1.72-2.12; SI 156, 154-166; PW 1.22, 0.90-1.22; MW 0.53, 0.37-0.53; PMI 230, 212-259; MTL 2.34, 1.77-2.34 (13 measured).

Anterior clypeal margin with denticulate, median flange. Clypeus sinuate in profile, posteriorly rounding into moderately impressed basal margin. Frontal triangle poorly indicated. Frontal carinae sinuate with narrowly raised margins; central area relatively wide with distinct frontal furrow. Sides of head in front of eyes moderately convex towards mandibular bases; behind eyes, sides widely rounding into convex occipital margin. Eyes convex, in full face view exceeding lateral cephalic outline. Ocelli lacking. Pronotal dorsum with humeri rounded; lateral margins converging towards distinctly impressed promesonotal suture. Mesonotum with margins strongly converging posteriorly; metanotal groove only weakly impressed. Propodeal margins terminating in rather slender, horizontal, divergent spines with tips weakly turned outwards. Petiole with anterior face straight, rounding dorsally into very slender, distinctly obliquely raised, divergent spines; posterior face of petiole distinctly swollen towards base.

Mandibles finely, longitudinally striate with numerous piliferous pits. Head and mesosoma closely reticulate-punctate; spines sculptured at bases, smooth and polished towards tips. Gaster finely shagreened.

Mandibles at mastiticatory borders with numerous, curved, pale golden hairs and short, more appressed hairs towards bases. Anterior clypeal margin with several anteriorly projecting longer setae medially and fringe of short setae lining margin laterally. Head, including clypeus, mesosoma, petiole, gaster and appenages with numerous, mostly erect, relatively short hairs; head in full face view with numerous short hairs breaking lateral cephalic outline; antennal scapes with numerous, very short, semierect, bristle-like hairs. Gastral dorsum with abundant, somewhat longer, semierect, pale golden hairs; hairs distinctly longer and posteriorly directed on venter and around apex of gaster. Silvery, appressed pubescence in various densities over most of head and body surfaces; pubescence more pale golden on dorsum of first gastral tergite and somewhat laterally diffused into more silvery towards sides and on venter.

Vertex of head, dorsum of mesosoma, petiole, dorsum of gaster and spines, black; mandibles, front, sides and venter of head, sides of pronotum, venter of gaster and appendages medium to dark reddish-brown.

Type Material


Type deposition: Holotype and 2 paratypes in ; 2 paratypes each in, and ; 1 paratype each in ,  and.

Etymology
After the collector of the type series specimens, Tom Weir of the ANIC of the Ecosystem Sciences, Canberra.