Ponera borneensis

Identification
Taylor (1967) - The basic characters distinguishing this species from its relatives Ponera elegantula and Ponera augusta are incorporated in the accompanying key to species of Ponera. For details of relationships and diagnostic features of these species see P. elegantula.

Distribution
Known only from the mountains of central Borneo.

This taxon was described from Borneo.

Castes
Male and larval characters not known. One of the worker paratypes has the remains of a pupal cocoon in its jaws; so augusta presumably has enclosed pupae. (Taylor 1967)

Nomenclature

 *  borneensis. Ponera borneensis Taylor, 1967a: 69, figs. 61, 62 (w.q.) BORNEO.

Worker
HL 0.62-0.65 mm; HW 0.53-0.57 mm; SL 0.46-0.49 mm; CI 86-88; SI 86-89; PW 0.42-0.44 mm; PNL 0.22-0.23 mm; PH 0.41-0.44 mm; DPW 0.36-0.39 mm; PNI 86-90. General form as shown in accompanying figures. Close to Ponera augusta of New Guinea, differing from it in the following characters:

1. Those indicated in the dimensions above-narrower head (i.e., lower cephalic index), relatively high petiolar node, higher petiolar node index.

2. Apical mandibular teeth occupying slightly less than 1/2 the masticatory border, followed by about 10 to 12 minute, indistinct denticles. Palpal formula: Maxillary 2: Labial 2 (2 specimens dissected).

3. Eyes averaging slightly larger-maximum diameter 0.07-0.09 mm, with about 12 to 16 irregular facets.

4 Scapes shorter, their apices almost exactly reaching median occipital border when they are laid back on head.

5. Mesometanotal and lateral mesonotal sutures much less distinctly marked. The former a more or less distinct incised line, sometimes difficult to see, except in reflected light.

6. Mandibles smooth and shining. Clypeus shining in center, with scattered indistinct punctures; irregularly shagreened at sides. Front of head opaque, coarsely and closely punctate, punctures slightly smaller and more separated than in augusta. Sides of head moderately shining, with a cover of medium punctures (diameter ca 0.006 mm) separated by distances of slightly more than their maximum diameter. Scapes moderately coarsely shagreened; mesosomal dorsum feebly shining, sculpturation similar to sides of head but slightly more dense; mesonotal puncturation not markedly more dense than pronotum, that of propodeal dorsum less distinctly impressed. Punctures of mesonotum less spaced than those of pronotum and propodeum. Sides of mesosoma strongly shining, almost completely lacking sculpture except for relatively fine longitudinal striation on entire lower halves of mesepisternum and metepisternal areas. Node and gaster moderately shining, with scattered, pilosity-bearing, point punctures. The sculpturation of borneensis, particularly that of the sides of the head and the postcephalic areas, is thus considerably less intense than in augusta.

7. Pilosity and pubescence as in P. augusta.

8. General color dark blackish brown, with reddish brown infuscation on node and gaster, notably on subpetiolar process and gastric apex. Mandibles, antennae and legs bright golden brown.

Worker types. The above description is based on a series of 13 workers. One has been designated as holotype, the remainder as para types. The holotype has the following dimensions: HL 0.64 mm; HW 0.56 mm; SL 0.48 mm; CI 87; SI 86; PW 0.42 mm; PNL 0.23 mm; PH 0.43 mm; DPW 0.37 mm; PNI 88.

Queen
Paratypes. 3 alates were originally mounted with the workers described above. One is callow and the others show signs of shrinkage due to drying. This is especially apparent in the node, where the posterior face is fairly strongly concave and the apical crest rather acute in side view. This condition, which is also seen in several paratype workers, is clearly due to contraction of the transverse faces of the node and is not normal for the species. The most intact specimen (MCZ collection) has the following dimensions: HL 0.68 mm; HW 0.58 mm; SL 0.52 mm; CI 85; SI 90; PW 0.53 mm; PNL 0.25 mm; PH 0.49 mm; DPW 0.42 mm; PNI 79; maximum diameter of compound eye 0.21 mm; ocular index 36. Scape almost exactly reaching median occipital border ; ocelli distinctly developed; parapsidal lines present. Wing venation of coarctata type. Sculpture and coloration as in worker, wing veins very pale yellowish brown. Palpal formula: Maxillary 2: Labial 2 (callow inspected).

Type Material
BORNEO: Mt Tibang, 1500 m (E. Mjoberg), collected from a rotting log.

Holotype and paratypes deposited in collection; duplicate paratypes, worker and queen, in and ; workers only in, Forel Coll., and.