Polyrhachis bispinosa

Nothing is known about the biology of .

Identification
A member of the Polyrhachis gravis species-group. Kohout (2013) - The characteristic distinctly swollen base of the petiole makes this species easily recognisable.

Key to Polyrhachis gravis species-group workers

Distribution
The distribution of P. bispinosa appears to be restricted to the northern parts of the Northern Territory and the Mt Isa basin in north-western Queensland.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  bispinosa. Polyrhachis (Campomyrma) bispinosa Kohout, 2013: 95, figs. 1A-B, E-F (w.) AUSTRALIA.

Worker
(holotype cited first): TL c. 8.72, 7.51-8.72; HL 2.21, 1.93-2.21; HW 1.93, 1.68-1.93; 087, 86-89; 5L 2.28, 2.06-2.28; SI 118, 113-123; PW 1.62, 1.40-1.62; MTL 2.93,2.34-2.93 (4 measured).

Mandibles with 5 teeth distinctly reducing in length towards base. Anterior clypeal margin widely medially truncate with truncate portion distinctly denticulate. Clypeus with blunt, poorly defined median carina; weakly sinuate in profile with weakly impressed basal margin. Frontal carinae sinuate with weakly raised margins; central area almost flat with poorly indicated frontal furrow. Sides of head in front of eyes rounding into mandibular bases in weakly convex line; behind eyes sides forming distinct, narrowly rounded, almost right-angled occipital corners, before converging into relatively narrow occipital margin. Eyes convex, in full face view clearly breaking lateral cephalic outline. Ocelli lacking. Pronotal humeri distinctly angular with margins converging anteriorly towards pronotal collar; lateral margins of pronotal dorsum converging into well impressed promesonotal suture.

Dorsum of mesonotum with lateral margins strongly converging posteriorly towards distinct metanotal groove, forming almost straight line with lateral margins of propodeum and terminating in closely approximated, rather blunt, propodeal teeth; margins of teeth continued for short distance downwards into steeply concave propodeal declivity. Petiole with base distinctly swollen in lateral view; sides strongly convex towards dorsum armed with pair of closely approximated, dorsoposteriorly directed, slender spines; lateral petiolar spines reduced to mere angles. Anterior face of first gastral segment flat in lateral view, widely rounding onto dorsum; anterodorsal margin of first gastral tergite with blunt transverse carina.

Mandibles very finely striate with numerous piliferous pits. Head between frontal carinae and eyes distinctly, rather regularly, longitudinally striate; sculptural pattern distinctly less regular towards sides and on vertex where it is rugose with numerous piliferous pits. Dorsum of mesosoma generally longitudinally striate, with striae on pronotal dorsum somewhat posteriorly diverging and curving towards posterior corners of segment. Sides of mesosoma finely, more-or-less uniformly, wrinkle. Propodeal declivity and petiole finely, transverse striate. Gaster with base and sides of first tergite rather polished, intensity of sculpture increasing dorsally, becoming very finely, longitudinally striate towards posterior margin of segment; subsequent tergites finely reticulate-punctate.

Mandibles with numerous curved, golden hairs. Anterior clypeal margin with several, anteriorly directed, unequal length golden setae medially and shorter setae fringing margin laterally. Numerous erect to semierect hairs on head, mesosoma, gaster and legs, hairs longest on clypeus and gastral venter and shortest on dorsum of mesosoma; antennae with numerous short, bristle-like semierect hairs.

Black; mandibles medium reddish-brown with teeth black. Clypeus dark reddish brown with anterior margin narrowly bordered black. Antennal scapes dark reddish-brown with funiculi a shade lighter. Legs, including middle and hind cozae distinctly orange, tarsi a shade darker.

Type Material


Type deposition: Holotype in ; 2 paratype workers each in and ; 1 paratype worker each in  and.

Etymology
Name derived from the combination of the Latin words bi -, meaning two and spina, meaning thorn, spine, with reference to the twin dorsal petiolar spines.