Polyrhachis ogatai

Nothing is known about the biology of .

Identification
A member of the Polyrhachis vestita species group.

Kohout (2008) - Polyrhachis ogatai is easily recognised among members of the vestita-group by its large size and the peculiar process at the apex of antennal scape (see image in caste section below).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Sulawesi.

Castes
Known only from the worker caste.

Nomenclature

 *  ogatai. Polyrhachis ogatai Kohout, 2008a: 281, figs. 5E-F, 6B (w.) INDONESIA (Sulawesi).

Worker
Holotype: TL c. 15.12; HL 3.63; HW 2.77; CI 76; SL 4.69; SI 169; PW 2.47; MTL 5.64. Anterior clypeal margin arcuate, with two shallow notches medially. Clypeus in profile sinuate, shallowly concave anteriorly, with short, distinct carina before posteriorly rounding into well impressed basal margin, laterally indicated by a thin line breaking sculpturation. Frontal triangle indistinct. Frontal carinae with anteriorly sinuate, highly and steeply raised laminate lobes; rather flat posteriorly; central area concave with short frontal furrow. Antennal scapes distinctly broadened apically, somewhat dorso-ventrally compressed and shallowly excavated on ventral aspect, with dorsally projecting, blunt process (Fig. 6B) near their apices. Sides of head in front of eyes only weakly convex, converging towards mandibular bases; behind eyes sides rounding into convex, strongly narrowed and medially emarginate, occipital margin. Eyes convex, in full face view not reaching lateral cephalic outline. Ocelli lacking. Pronotal dorsum with pair of relatively short, anteriorly directed spines; lateral edges of spines continuous with weakly posteriorly converging pronotal margins. Mesonotum wider than long with lateral margins converging posteriorly. Propodeal dorsum only marginally wider than long with lateral margins parallel, terminating posteriorly in short, weakly raised ridges; margins of ridges continued inwards and slightly downwards for a short distance; propodeal dorsum descending into declivity in only weakly curved, medially uninterrupted line. Petiole with anterior and posterior faces virtually flat in profile, strongly converging dorsally; dorsal petiolar margin shallowly emarginate medially, somewhat jagged laterally and terminating in short denticles. Anterior face of first gastral segment very high, distinctly higher than petiole, broadly rounding onto dorsum.

Mandibles rather polished with fine, longitudinal striae. Clypeus, front and sides of head rather distinctly reticulate-punctate, with reticulae on clypeus somewhat antero-medially converging. Vertex, dorsum of mesosoma, petiole and gaster more finely reticulate-punctate with weak satin gloss.

Mandibles along outer margin and near masticatory borders with several golden hairs with a distinct rusty-red tint. A few, relatively long setae of same colour arising medially from anterior clypeal margin with shorter setae fringing margin laterally. Numerous, semierect and erect, mostly black or dark brown, medium length hairs on clypeus, sides of head and along frontal carinae. Distinctly longer, longest almost as long as the greatest diameter of eye, somewhat anteriorly curved, black or rusty-brown hairs, rather abundant on vertex and mesosomal dorsum; shorter, dorsally curved, dark brown or rusty-brown hairs on sides of mesosoma. Front coxae and legs, except dorsal surfaces of femora, with numerous black and brown hairs. Middle and hind femora towards distal ends with some shorter, erect hairs dorsally. Petiole with numerous, mostly black, shorter hairs. Gaster dorsally and ventrally with black and brown, relatively long, posteriorly directed, hairs. Closely appressed, rusty brown pubescence on most body surfaces, except mandibles, clypeus, front and sides of head; pubescence most dense and distinctly longer on mesosoma and extremely short, with very distinct rusty-red tint on vertex, petiole and gaster.

Colour. Black throughout; only apical mandibular teeth and extreme tip of apical funicular segments reddish-or yellowish-brown.

Type Material
HOLOTYPE: SULAWESI SELATAN, Kayulagi nr Mangktana, 02°23’S, 120°47’E, 600m, 20.x.1999, K. Ogata & K. Masaoka (worker). Unique holotype in (QMT144150).

References based on Global Ant Biodiversity Informatics

 * Kohout, R. J. 2008. A review of the Polyrhachis ants of Sulawesi with keys and descriptions of new species (Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum 52:255-317.