Polyrhachis inducta

The Polyrhachis inducta types were collected from a nest under the bark of tree.

Identification
It is rather similar to Polyrhachis nomo and Polyrhachis decumbens with which it shares the dense cover of appressed and decumbent hairs. It differs from both in the outline of the mesosoma that in Polyrhachis decumbens and Polyrhachis nomo is distinctly more convex anteriorly with the mesonotum and propodeum rather weakly rounding into an obliquely descending propodeal declivity. In Polyrhachis inducta the outline of the pronotal dorsum is only weakly convex with the mesosomal and propodeal dorsa distinctly higher and curving abruptly into a vertical propodeal declivity. Polyrhachis inducta also differs by the presence of distinct propodeal spines that are virtually absent in Polyrhachis decumbens and Polyrhachis nomo. (Kohout 2006)

Distribution
New Guinea

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

Abundance
Known only from the type material.

Castes
Known only from (type) workers.

Nomenclature

 *  inducta. Polyrhachis inducta Kohout, 2006b: 127, figs. 9E-F (w.) NEW GUINEA.

Worker
Dimensions (holotype cited first): TL c. 5.34, 5.09-5.95; HL 1.43, 1.34-1.50; HW 1.37, 1.25-1.43; CI 96, 93-98; SL 1.87, 1.72-1.90; SI 136, 127-140; PW 1.12, 1.00-1.18; MTL 2.12, 2.00-2.21 (13 measured)

Clypeus in profile straight, with indication of rather weak, median tubercule just before narrowly rounding into medially impressed basal margin. Frontal triangle very weakly impressed, indistinct. Frontal carinae sinuate with weakly raised margins; central area relatively narrow, weakly concave with short frontal furrow. Sides of head in front of eyes almost straight, converging towards mandibular bases; behind eyes sides widely rounding into convex occipital margin. Eyes convex, in full face view distinctly breaking lateral cephalic outline. Ocelli lacking; vertex with only shallow punctures indicating their relative positions. Pronotum in dorsal view widely rounded, greatest width of pronotal dorsum at mid-length of segment. Mesosoma in lateral view with pronotum only weakly convex, mesonotal and propodeal dorsa more highly convex; promesonotal suture distinct; metanotal groove lacking; propodeal dorsum armed with relatively short, acute, upturned spines; declivity virtually vertical. Petiole with anterior face straight, posterior face convex; dorsum armed with four spines; dorsal pair triangular; lateral pair more slender and distinctly longer. Subpetiolar process acute anteriorly, bluntly angular posteriorly. Anterior face of first gastral segment higher than apices of dorsal petiolar spines.

Mandibles finely rugose. Head, mesosoma and gaster shagreened; sculptural intensity markedly increasing laterally with sides of mesosoma and base of petiole distinctly reticulate-rugose; meso- and notably metapleaurae deeply, irregularly, foveolate-rugose. Whole body covered with numerous piliferous pits and shallow punctures.

Mandibles with numerous semierect hairs along masticatory borders and very short appressed hairs towards bases. Anterior clypeal margin with a few medium length, anteriorly directed setae medially and several very short setae laterally. A few pairs of longer, erect hairs near anterior and basal clypeal margins and along frontal carinae; single pair of long hairs on vertex. Fore coxae with a few erect hairs. Posterior margins of gastral segments with numerous erect hairs. Whole body with dense, short, appressed and decumbent hairs, those on dorsum of mesosoma more erect than hairs on head and gaster.

Colour. Black; clypeus, sides of head and gaster diffusely reddish-brown. Antennal scapes very dark brown with distal ends and funiculi distinctly lighter. Mandibles, coxae and tarsi dark reddish-brown with mandibular masticatory borders, trochanters, femora and tibiae a shade lighter.

Type Material
HOLOTYPE: PAPUA NEW GUINEA, Morobe Prov., Bulolo, 21.xii.1970, B.B. Lowery (worker). PARATYPES: data as for holotype (12 workers). Holotype and 2 paratypes in ; 2 paratypes each in, , and.

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.