Polyrhachis cybele

Polyrhachis cybele is a relatively uncommon species distributed from Borneo, Sumatra and Java to Sulawesi and the Philippines (Kohout, 2013).

Identification
Polyrhachis cybele is a very characteristic species discussed in detail, together with the closely similar Polyrhachis aculeata Mayr, Polyrhachis gibbosa Forel and Polyrhachis hemiopticoides Mukerjee, by Kohout (2008: 258, 271). The distinguishing characters separating P. cybele from the closely similar species Polyrhachis dimoculata are given below in the remarks section of that species.

Distribution
This taxon was described from Borneo.

Nomenclature

 *  cybele. Polyrhachis (Hemioptica) aculeata subsp. cybele Wheeler, W.M. 1919e: 126 (w.) BORNEO. Combination in P. (Myrma): Emery, 1925b: 205. Raised to species: Kohout, 2008a: 271.

Description
Kohout (2013): Worker. Dimensions (syntype cited first): TL c. 7.00, 5.95-7.96; HL 1.68, 1.53-1.87; HW 1.43, 1.28-1.56; CI 85, 75-85; SL 2.09, 1.81-2.28; SI 146, 133-150; PW 1.22, 1.06-1.50; MTL 2.15, 1.96-2.46 (1+25 measured).

Specimens from Sumatra are rather similar to those of the Bornean population, but those from Sulawesi and Java differ in a number of characters. Sulawesi specimens are characterised by a distinctly broader pronotal dorsum and shorter antennal scapes (SI 133-140 versus 144-150 in other populations). In contrast, the single available series of specimens from Java (Kebun Raya, Bogor), differ markedly from other populations by their distinctly more slender body (PW 1.06-1.18 versus 1.22-1.50 in specimens from Borneo, Sumatra and Sulawesi). The Bogor specimens also have the body hairs distinctly less abundant and virtually absent from the antennal scapes, vertex of the head, dorsum of the mesosoma and most of the gastral dorsum, except the apex. However, specimens from across the entire distribution are closely similar in their general appearance and I believe all the examined populations are conspecific.

Queen (not previously described). Dimensions: TL c. 8.26; HL 1.84; HW 1.59; CI 86; SL 2.18; SI 137; PW 1.72; MTL 2.34 (1 measured).

Queen larger than worker with usual characters identifying full sexuality, including three ocelli, complete thoracic structure and wings. Pronotal spines distinctly shorter, only marginally longer than their basal width, anteriorly directed. Mesoscutum somewhat wider than long; lateral margins converging anteriorly into smoothly rounded anterior margin; median line distinct; parapsides only weakly raised posteriorly; mesoscutum in profile with widely rounded anterior face and almost flat dorsum posteriorly. Mesoscutellum moderately convex, only marginally elevated above dorsal plane of mesosoma. Propodeal dorsum convex in outline with lateral margins terminating in narrowly rounded, medially continuous ridges that form rather thin, transverse, medially bowed line dividing propodeal dorsum from declivity. Petiole biconvex in profile, dorsolateral spines reduced to rather blunt, wide-based teeth, only marginally longer than acute lateral teeth; dorsal margin very shallowly, medially notched. Rather smooth and highly polished dorsal body surfaces, pilosity, pubescence and colour, very similar to worker.