Polyrhachis montana

This species is undoubtedly endemic to Borneo and is known only from the original collections made by E. Mjöberg at Mt Murud and Mt Dulit in Sarawak.

Identification
A member of the bihamata group of the subgenus Polyrhachis.

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

Castes
Sexuals and immature stages unknown.

Nomenclature

 *  montana. Polyrhachis montana Hung, 1970: 23, figs. 16-22 (w.) BORNEO.

Worker
Holotype: HW 2.20 mm, HL 2.43 mm, CI 90, SL 3.00 mm, SI 141, PW 1.13 mm, MPL 2.60 mm, MTL 4.13 mm, PSEI 200, PH 1.90 mm. Mandibles with 5 teeth sequentially reducing in length, the apical is about twice as long as the basals. Clypeus convex, slightly carinated. Head, excluding the mandibles, somewhat longer than broad, slightly rounded. Median ocellus present. No lateral ocelli. Alitrunk more or less rounded. Pronotum slightly marginated with two spines rather stout at base pointing outwards and curved with the tips slightly pointing backwards. Mesonotum with two widely separated pyramidal spines raising upwards, outwards and bending backwards at an angle greater than 90 degrees. Metanotal groove obscure. Propodeum with the basal face about three times as long as the declivity. Declivity with one inclined ridge on each side forming an isosceles triangle with the top angle and the bottom leg notched. No distinct ridge between the basal face and the declivity. Petiole columnar, but rather flattened, bearing two long hook-shaped spines diverging widely from their bases. Gaster slightly elliptical with the tergite of the first segment covering about two-fifths of the gaster. Body densely covered with light brown suberect hairs. Antennae and head very dusky red. Mandibles dusky red. Alitrunk and petiole moderate reddish-brown. Pronotal, mesonotal and petiolar spines black at tip. Legs dark reddish-brown. Gaster dark reddish-brown with the first segment slightly lighter.

Kohout (2014) - (paratypes): TL c. 10.73 – 10.99; HL 2.37 – 2.52; HW 2.12 – 2.24; CI 89 – 90; SL 2.87 – 3.17; SI 135 – 141; PW 1.10 – 1.16; PeH 2.07 – 2.17; PeI 86-89; MTL 4.03 – 4.38 (4 measured).

Type Material
Kohout (2014) - Holotype and paratype workers. Type locality: BORNEO, SARAWAK, Mt Murud, (E. Mjöberg), (Type 31773),,  (examined).

References based on Global Ant Biodiversity Informatics

 * Hung A. C. F. 1970. A revision of ants of the subgenus Polyrhachis Fr. Smith (Hymenoptera: Formicidae: Formicinae). Oriental Insects 4(1): 1-36.
 * Kohout R. J. 2014. A review of the subgenus Polyrhachis (Polyrhachis) Fr. Smith (Hymenoptera: Formicidae: Formicinae) with keys and description of a new species. Asian Myrmecology 6: 1-31.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
 * Robson Simon Database Polyrhachis -05 Sept 2014