Polyrhachis euryala

Donisthorpe (1941) in his account of the synonymous rastellata var. baduri: "Miss L. E. Cheesman took a number of workers and three winged females in a carton nest under leaves of Pandanus." Nothing more is known about the biology of Polyrhachis euryala.

Identification
Donisthorpe (1938) - Polyrhachis euryala is distinctly more slender than Polyrhachis rastellata with the greatest width of the pronotal dorsum in the middle of its length. Polyrhachis rastellata is more robust, notably across the pronotum which is widest across, or just behind the shoulders.

Kohout (2008) - When describing Polyrhachis pagana, Santschi compared his new variety to Polyrhachis euryala and Polyrhachis rastellata. He noted that it differed from P. euryala by having the dorsal petiolar spines longer and finer than the lateral pair, and from P. rastellata by its black appendages. Besides the characters listed above, P. euryala differs from both other species by its distinctly slender mesosoma with the greatest width of the pronotal dorsum at its mid-length. In contrast, both Polyrhachis rastellata and P. pagana feature a more robust pronotal dorsum which is widest across or just behind the shoulders. The two latter species differ mainly by the colour of their legs that are mostly light to medium-red or orange in P. rastellata and black in P. pagana. In addition, the mesosomal profile in P. rastellata is distinctly uneven, with a rather flat or shallowly impressed summit at the promesonotal suture and a weak depression indicating the relative position of the indistinct metanotal groove. In contrast, the mesosoma in P. pagana is almost evenly rounded (more like that in P. euryala), with only a slight change in the angle of the profile at the steeply descending propodeal declivity.

Distribution
Patchily distributed through the eastern islands of Indonesia and across New Guinea.

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

Nomenclature

 *  euryala. Polyrhachis euryalus Smith, F. 1863: 16 (w.) INDONESIA (Misool I.). Combination in P. (Cyrtomyrma): Emery, 1925b: 208. Junior synonym of rastellata: Mayr, 1872: 138; Bingham, 1903: 414. Revived from synonymy as subspecies of rastellata: Emery, 1900d: 720; Emery, 1925b: 208. Revived status as species: Donisthorpe, 1938c: 259; Dorow, 1995: 22. Senior synonym of torricelliana: Viehmeyer, 1914b: 50; Kohout, 2009b: 44; of baduri: Kohout, 2009b: 44. See also: Kohout, 2006b: 125. Current subspecies: nominal plus javana.
 * torricelliana. Polyrhachis rastellata var. torricelliana Viehmeyer, 1912: 9, fig. 11 (w.) NEW GUINEA. Junior synonym of euryala: Viehmeyer, 1914b: 50.
 * baduri. Polyrhachis (Cyrtomyrma) rastellata var. baduri Donisthorpe, 1941h: 63 (w.q.) NEW GUINEA. Junior synonym of euryala: Kohout, 2009b: 45.

Polyrhachis euryalus

Holotype worker in. Labelled “M.” (= Misool I.) and with a Donisthorpe type-label.

Worker
Length 2 ½ lines. Black, smooth and shining; the thorax rounded above, not spined; the outline, when viewed laterally, semicircular; the legs obscure ferruginous. Abdomen globose; the node of the peduncle with four spines, the two inner ones shorter than the lateral pair, but all short and acute.

Queen
Colour and sculpture as in worker. The scale is broader and the punctures on thorax and petiole a little coarser. Wings yellowish, pterostigma and veins yellowish-brown. Long. 7·0-7·5 mill. (Donisthorpe 1941)

Type Material
INDONESIA, Mysool Island, col. A.R. Wallace. Syntype workers and  – as reported by Kohout (2006).

Donisthorpe (1941) types of the synonymous rastellata var. baduri: JAPEN ISLAND: Mt. Baduri, 1000 ft., viii.1938, col. L. E. Cheesman.