Ponera elegantula

Rarely collected, what little is known comes from two collection records showing they were made in rotting logs in disturbed rain forest.

Distribution
Known only from a few localities at high elevations in NE New Guinea, where it occurs sympatrically with the related Ponera augusta at Aiyura, in the Eastern Highlands.

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

Nomenclature

 *  elegantula. Ponera elegantula Wilson, 1957b: 379 (w.q.) NEW GUINEA. Taylor, 1967a: 72 (m.l.).

Worker
The following notes are based on 19 workers from several accessions made by me at Aiyura, and on the holotype worker (MCZ collection). The Aiyura specimens agree with the holotype in all essential features, but average slightly larger in size. In the general summary of the features of the species given below, special mention is made of the characters of the holotype where they may be significant. Dimensions (holotype cited first): HL 0.70 mm, 0.72-0.74 mm; HW 0.56 mm, 0.58-0.62 mm; SL 0.49 mm, 0.52-0.54 mm; CI 80, 80-83; SI 87, 86-90; PW 0.42 mm, 0.45-0.47 mm (the pronotum of the holotype appears to be pinched through contraction in drying); PNL 0.21 mm, 0.23-0.25 mm; PH (obscured but ca.) 0.44 mm, 0.46-0.48 mm; DPW 0.38 mm, 0.38-0.41 mm; PNI 88, 83-87 (the relatively high value for the holotype is due to its narrowed pronotum). General features as shown in accompanying figures. The key, figures and dimensions given above should allow easy identification of elegantula, the additional specimens permit further qualification of the characters of this species as follows:

1. Posterior 1/2 of masticatory border of mandible with about 6 to 8 minute denticles.

2. Eyes 0.06 mm to 0.08 mm in maximum diameter, with about 11 to 15 facets, situated about 0.92 X the distance from lateral occipital border to midpoint of anterior genal border.

3. Scapes failing to reach median occipital border by about 0.2 to 0.5 X their thickness.

4. Mesometanotal suture variable in development, completely lacking on mesosomal dorsum in some specimens, including holotype; while other individuals have a very finely incised suture, visible only in strongly reflected light.

Palpal formula: Maxillary 2: Labial 2 (3 Aiyura specimens dissected).

Queen
The dimensions of Wilson's dealate paratype queen are: HL 0.76 mm; HW 0.62 mm; SL 0.53 mm; CI 82; SI 86; PW 0.52 mm; PNL 0.25 mm; PH 0.51 mm; DPW 0.44 mm; PNI 85; maximum eye length 0.16 mm; ocular index 26. Similar to queen of Ponera borneensis but distinguished by slightly larger size, narrower head, higher scape and petiolar node indices, and relatively small eyes (ocular index 26, opposed to 36 in borneensis). Antennal scapes failing to reach median occipital border by about 1/3 their maximum thickness. Sculpturation not markedly reduced relative to borneensis queen, perhaps indicating conservatism in evolution of queen structure compared to that of the worker. Propodeal dorsum moderately shining, with scattered medium puncturation (in borneensis it is subopaque, coarsely and closely punctate, with a tendency to longitudinal striation in the interpunctural reticulum).

A late pupal queen from Aiyura (acc. 2117) agrees with the holotype in general characters, its palpal formula is Maxillary 2: Labial 2 (dissected).

Male
A single male from Aiyura (acc. 2169) has the following dimensions: HL 0.58 mm; HW (across eyes) 0.65 mm; CI 112; WL 1.15 mm; PNL 0.26 mm; PH 0.40 mm; DPW 0.33 mm; maximum diameter of eye 0.28 mm; ocular index 43. Palpal formula: Maxillary 2: Labial 2 (dissected), as in queen castes. Structure of head, mandibles, antennae, mesosoma, wings, petiole and gaster as in Ponera pennsylvanica. Terminal abdominal sclerites and genitalia conforming to general plan for genus. Pygidial spine stronger than in Ponera coarctata, dorsal process of gonoforceps more strongly developed. Color black, mandibles, legs, antennae and gastric apex very dark brown, wing veins relatively dark brown.

Immature Forms
Larvae conforming to general plan for Indo-Australian members of genus, closely resembling those of P. alpha, with 3 pairs of dorsal abdominal glutinous tubercles.

Type Material
Tumnang, Huon Peninsula, NE New Guinea (Holotype and queen Paratype examined, coll.).

References based on Global Ant Biodiversity Informatics

 * CSIRO Collection
 * Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
 * Taylor R. W. 1967. A monographic revision of the ant genus Ponera Latreille (Hymenoptera: Formicidae). Pacific Insects Monograph 13: 1-112.
 * Wilson E. O. 1957. The tenuis and selenophora groups of the ant genus Ponera (Hymenoptera: Formicidae). Bulletin of the Museum of Comparative Zoology 116: 355-386.
 * Wilson E. O. 1958. Studies on the ant fauna of Melanesia III. Rhytidoponera in western Melanesia and the Moluccas. IV. The tribe Ponerini. Bulletin of the Museum of Comparative Zoology 119: 303-371.
 * Wilson Edward O. 1959. Adaptive Shift and Dispersal in a Tropical Ant Fauna. Evolution 13(1): 122-144