Polyrhachis hoffmanni

Nothing is known about the biology of .

Identification
A member of the penelope species-group in the Polyrhachis subgenus Hagiomyrma. Kohout (2013) - Polyrhachis hoffmanni is very similar to the sympatric Polyrhachis archeri and Polyrhachis anderseni but differs in the shape of the petiolar node, as discussed in the remarks section of P. archeri. Polyrhachis hoffmanni can also be easily separated by the relatively long hairs on most body surfaces which are completely absent in the two other species.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Males and immature stages unknown.

Nomenclature

 *  hoffmanni. Polyrhachis (Hagiomyrma) hoffmanni Kohout, 2013: 538, figs. 7E-F (w.) AUSTRALIA.

Worker
(holotype cited first): TL c. 6.60, 5.81-6.69; HL 1.62, 1.53- 1.62; HW 1.34, 1.25-1.34; CI 83, 82-83; SL 1.87, 1.75-1.87; SI 139, 133-142; PW 1.31, 1.20-1.31; MW 0.87, 0.78-0.87; PMI 150, 149-156; MTL 2.09, 1.93-2.09 (5 measured).

Anterior clypeal margin with denticulate median flange, laterally flanked by distinct, acute teeth. Clypeus with median carina; almost straight in profile, posteriorly rounding into shallow basal margin. Frontal triangle distinct. Frontal carinae with weakly and narrowly raised margins anteriorly, flat posteriorly; central area relatively wide with distinct frontal furrow. Sides of head in front of eyes converging in straight line towards mandibular bases; behind eyes, sides widely rounding into convex occipital margin. Eyes moderately convex, in full face view clearly exceeding lateral cephalic outline. Ocelli lacking. Pronotal humeri widely rounded; dorsum distinctly wider than long, widest near mid-length. Promesonotal suture distinct; mesonotal lateral margins converging posteriorly towards medially indistinct metanotal groove. Propodeum armed with relatively short, weakly divergent spines. Petiolar dorsum distinctly concave medially, armed with divergent, weakly elevated, acute spines; posterior face of petiole strongly convex. Anterior face of first gastral tergite distinctly higher that full height of petiole, widely rounding onto dorsum.

Mandibles densely longitudinally striate with piliferous pits towards masticatory borders. Head, mesosoma and petiole closely reticulate-punctate. Spines sculptured from bases, tips smooth and polished Gaster shagreened with sculpture distinctly coarser on dorsum.

Mandibles at masticatory and along outer borders with several, anteriorly inclined, golden hairs. Anterior clypeal margin medially with a few, anteriorly directed setae and fringe of shorter setae laterally. Several, mostly paired, rather long, curved hairs on clypeus, along frontal carinae, vertex and occipital corners; no hairs breaking lateral cephalic outline between eyes and mandibular bases in full frontal view. Long, variously curved hairs, as long as or longer than greatest diameter of eyes, scattered over most body surfaces. Gaster with abundant, long, posteriorly inclined, silvery hairs. Relatively long, silvery, appressed pubescence, generally untidy and rather diluted on dorsum of head and mesosoma; pubescence somewhat denser on pronotal shoulders and propodeal declivity. Gaster with abundant, golden, appressed pubescence on dorsum, completely hiding underlying sculpturation; pubescence silvery and much diluted on gastral venter.

Black; mandibles relatively light, reddish-brown, with teeth and outer borders lined with black. Clypeus, central area and appendages medium to dark reddish-brown; anterior clypeal margin and frontal carinae with narrow black margins. Gaster distinctly reddish-brown on venter.

Queen
TL c. 8.01; HL 1.78; HW 1.43; CI 80; SL 1.90; SI 133; PW 1.72; MTL 2.15 (1 measured). Apart from sexual characters very similar to worker except: mesoscutum wider than long with virtually flat dorsum in lateral view; median line distinct; parapsides flat. Mesoscutellum weakly convex, only marginally elevated above dorsal plane of mesosoma. Propodeal spines very short, bases broad; petiolar spines shorter than in worker, distinctly obliquely elevated, divergent. Sculpturation, pilosity and pubescence identical to worker. Colour generally as in worker, with only mandibles and appendages very dark, reddish-brown.

Type Material


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

Etymology
Named in honour of one of the collectors, Ben Hoffmann, of the CSIRO, TERC, Darwin, who has collected extensively across the Northern Territory, including Arnhem Tableland and adjacent islands.

References based on Global Ant Biodiversity Informatics

 * Kohout R.J. 2013. Revision of Polyrhachis (Hagiomyrma) Wheeler, 1911 (Insecta: Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum  Nature 56: 487577