Polyrhachis kebunraya

Polyrhachis kebunraya appears to be restricted to the type locality and is known only from the specimens collected by Simon Robson and Fuminori Ito.

Identification
A member of the Polyrhachis aculeata species group in the subgenus Myrma

Polyrhachis kebunraya is most similar to Polyrhachis dimoculata, described above, from Borneo. They share the fine reticulate-punctate sculpturation of the dorsal body surfaces, distinctly striate pronotal spines, including their bases, and a virtual lack of pilosity on the vertex of the head, dorsum of the mesosoma, petiole and dorsum of the gaster. However, the sculpture on the dorsum of the head and mesosoma in P. kebunraya is distinctly longitudinally directed and covered with a very fine pile of closely appressed pubescence that is completely lacking in P. dimoculata. The truncate eyes in P. kebunraya are distinctly more convex and more protracted posteriorly and the sides of head behind the eyes are produced into short, blunt, carinae that are absent in P. dimoculata. Also, the antennal scapes in P. kebunraya have several hairs along their superior edge that are completely lacking in P. dimoculata. (Kohout 2013)

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

Castes
Sexuals and immature stages unknown.

Nomenclature

 *  kebunraya. Polyrhachis (Myrma) kebunraya Kohout, 2013: 165, figs. 55-56, 59-60 (w.) INDONESIA.

Description
Description. Worker. Dimensions (holotype cited first): TL c. 7.31, 7.21-7.31; HL 1.84, 1.81-1.87; HW 1.34, 1.31-1.37; CI 73, 72-73; SL 2.37, 2.34-2.40; SI 177, 175-179; PW 1.28, 1.25-1.31; MTL 2.43, 2.40-2.50 (1+2 measured).

Mandibles with 5 teeth. Anterior clypeal margin arcuate, narrowly medially truncate. Clypeus with blunt median carina, virtually straight in profile, posteriorly rounding into rather shallowly impressed basal margin. Frontal triangle distinct. Frontal carinae sinuate with strongly raised margins; central area narrow with distinct median furrow. Sides of head in front of eyes converging towards mandibular bases in evenly convex line; behind eyes sides produced into short, blunt carina extending towards occipital corners. Eyes distinctly convex, strongly posteriorly truncate, in full face view clearly breaking lateral cephalic outline. Ocelli lacking. Dorsum of mesosoma evenly convex in profile; pronotal humeri armed with rather long, acute spines; dorsum of each spine with longitudinal carina running from base towards tip; outer edge of spine acute, smoothly merging with lateral margin of pronotal dorsum. Promesonotal suture distinct, but relatively flat. Mesonotal dorsum with lateral margins narrowly rounded and weakly raised anteriorly, widely rounded and flat posteriorly; metanotal groove impressed laterally, indistinct medially. Propodeal dorsum with lateral margins distinctly converging posteriorly and terminating in narrowly rounded, moderately raised ridges that continue medially and merge, forming straight transverse carina dividing propodeal dorsum from shallowly concave declivity; secondary carinae extends from propodeal margins towards propodeal spiracles, dividing declivity from sides of propodeum. Petiole biconvex in profile, armed with a pair of dorsolaterally and posteriorly directed, acute spines situated on dorsolateral angles of petiole; bases of spines close to posterior face of petiole with dorsal margin of petiole clearly visible in lateral view (Fig. 60); shorter, dorsally emarginate, tooth situated laterally below base of each spine. Anterior face of first gastral segment concave to accommodate posterior face of petiole, anterodorsal margin distinctly lower than full height of petiolar node.

Mandibles finely, longitudinally striate with numerous piliferous pits. Clypeus finely reticulate-punctate, sculpture on dorsum and sides of head distinctly longitudinally organised. Dorsum of mesosoma finely longitudinally striate, striae more prominent on pronotal spines and along lateral mesosomal margins; petiole and gaster very finely reticulate-punctate. Tips of pronotal and petiolar spines highly polished; propodeal declivity, petiole and gaster finely shagreened, semipolished.Mandibles along masticatory and outer borders with semierect, relatively short, golden hairs. Anterior clypeal margin with a few rather long, anteriorly directed, golden setae medially and few very short setae laterally. Numerous moderately long, erect, golden hairs on clypeus, along frontal carinae and a few shorter hairs on vertex; several shorter hairs along superior edge of antennal scapes. Hairs totally absent from dorsum of mesosoma and petiole. Only a few moderately long hairs on anterior and posterior faces of fore coxae. Gaster with numerous posteriorly directed hairs around apex and on venter.

Colour. Black throughout, only extreme tip of apical funicular segment reddish brown.

Etymology
Named after the type locality, Bogor Botanical Gardens, popularly known as Kebun Raya.

References based on Global Ant Biodiversity Informatics

 * Kohout R. J. 2013. A review of the Polyrhachis aculeata species-group of the subgenus Myrma Billberg (Hymenoptera: Formicidae: Formicinae), with keys and descriptions of new species. Australian Entomologist 40(3): 137-171.