Polyrhachis sedlaceki

Nothing is known about the biology of Polyrhachis sedlaceki.

Identification
Polyrhachis sedlaceki is easily distinguished from all other New Guinean Cyrtomyrma by its highly polished appearance and complete lack of dorsal pilosity. It also differs in the unique shape of the petiole that is armed with two long, posterolaterally directed spines. All other known New Guinean species feature a normal scale-like petiole. (Kohout 2006)

Distribution
Known only from the type locality - PAPUA NEW GUINEA, Morobe Prov.,

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

Abundance
Known only from the type material.

Castes
Known only from workers.

Nomenclature

 *  sedlaceki. Polyrhachis sedlaceki Kohout, 2006b: 132, figs. 11A-B (w.) NEW GUINEA.

Worker
Dimensions (holotype cited first): TL c. 5.29, 5.59; HL 1.37, 1.40; HW 1.37, 1.40; CI 100, 100; SL 1.62, 1.65; SI 118, 118; PW 1.00, 1.03; MTL 1.93, 1.96 (2 measured).

Clypeus convex in profile, narrowly rounding into medially impressed basal margin. Frontal triangle only weakly impressed. Frontal carinae sinuate with rather flat margins; central area with short frontal furrow. Sides of head in front of eyes weakly convex, strongly converging towards mandibular bases; behind eyes sides rounding into convex occipital margin. Eyes convex, in full face view clearly breaking lateral cephalic outline. Ocelli lacking. Pronotum in dorsal view with humeri widely rounded; greatest pronotal width at mid-length of segment. Mesosoma in profile with pronotum strongly convex; promesonotal suture distinct, rather flat; mesonotal and propodeal dorsa weakly convex, rounding into declivity in even curve; metanotal groove lacking. Petiole with anterior face rounding onto rather blunt dorsal margin, posterior face convex; lateral spines long, slender, directed backwards; dorsal pair reduced to minute denticles. Subpetiolar process acute anteriorly, angular posteriorly. Anterior face of first gastral segment higher than dorsum of petiole, narrowly rounding onto dorsum of segment. Mandibles very finely, superficially sculptured. All body surfaces highly polished, with only very fine, microscopic sculpturation and numerous, very shallow piliferous pits.

Mandibles with several rather short, semierect hairs near masticatory borders. Anterior clypeal margin with a few, anteriorly directed setae medially and several shorter setae laterally. A few, medium length, erect hairs fringing apex of gaster. Extremely short, appressed hairs, arising from numerous pits, in various densities, over all body surfaces.

Colour. Black; mandibles reddish-brown with masticatory borders a shade lighter. Antennae dark brown with distal ends of scapes yellowish-brown and funicular segments progressively lighter towards apex. Legs and gaster rather dark, reddish-brown; tarsi very dark brown.

Type Material
HOLOTYPE: PAPUA NEW GUINEA, Morobe Prov., Bulolo R. Valley, c. 5km N of Wau, 07°17’S, 146°42’E, c. 1000m, 12.vi.1963, rf., J.& M. Sedlácek (worker). PARATYPE: data as for holotype (worker). Holotype (Type QMT99346) in, paratype in.

References based on Global Ant Biodiversity Informatics

 * Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
 * Kohout R.J. 2006. Review of Polyrhachis (Cyrtomyrma) Forel of Australia, Borneo, New Guinea and the Solomon Islands with descriptions of new species. Memoirs of the Queensland Museum 52: 87-146.