Ponera colaensis

My collections were made in disturbed rain forest in the Nandarivatu Forestry Nature Preserve at 840 m, and from relatively undisturbed forest on the slopes of Mt Lomolaki, at about 900 m. The majority of the specimens were taken from Berlese funnel samples of leafmold, moss off rotting logs, or debris from a tree fern stump. Accession No. 29 consisted of several workers taken with pupae under spongy moss covered bark on a rotting log. (Taylor 1967)

Identification
Taylor (1967) - One of the larger members of the taipingensis species group; somewhat similar to the Malayan Ponera taipingensis, but distinguished from it by the narrower head and wider petiolar node (cephalic index 8 1-83, petiolar node index 88-91 as opposed to 84-86 and 84-85 respectively in taipingensis). Ponera syscena (New Guinea) and Ponera loi (Samoa) are both similar to colaensis, but they have much narrower petiolar nodes (PNI 79-82 in syscena, 78-82 in loi).

P. colaensis is the only known Fijian Ponera species lacking an incised dorsal mesometanotal suture. The other Fijian species are all smaller, except for the slightly larger Ponera manni (HW 0.57 mm in the unique holotype), which has a much narrower petiolar node (PNI 73 opposed to 88-91 in colaensis).

The unique known queen of colaensis differs from those of the related P. loi by her smaller size, longer scapes, and broader petiolar node (HW 0.54 mm; SI 91; PNI 82, opposed to 0.60-0.63 mm; 83 -87, and 75-76 respectively in P. loi).

Distribution
A species apparently endemic to the Fiji Is. (Viti Levu and Lau group).

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

Biology
Beyond some habitat information from collection labels not much is known about Ponera colaensis.

Castes
Male and larva unknown; pupae of all castes enclosed in cocoons. (Taylor 1967)

Nomenclature

 *  colaensis. Ponera colaensis Mann, 1921: 417 (w.) FIJI IS. Santschi, 1928c: 68 (q.). See also: Taylor, 1967a: 58.

Worker
Taylor (1967) - The following dimensions are those of the holotype (USNM) and a single worker (MCZ) with labels identical to those of the holotype. This latter specimen was apparently overlooked by Mann at the time of description of the species. HL 0.62 mm, 0.61 mm; HW 0.50 mm; SL 0.45 mm; CI 81, 82; SI 90; PW 0.42 mm, 0.40 mm; PNL 0.20 mm; PH 0.43 mm; DPW 0.37 mm, 0.36 mm; PNI 88, 90.

Thirty additional workers I collected at Nandarivatu, Viti Levu, have the following measurements and indices: HL 0.62-0.65 mm; HW 0.50-0.54 mm; SL 0.46-0.49 mm; CI 81 -83; SI 88-92; PW 0.41-0.44 mm; PNL 0.20-0.22 mm; PH 0.41-0.43 mm; DPW 0.36-0.38 mm; PNI 88-91.

Mann's diagnosis is generally adequate, but the following additional notes are pertinent:

1. Clypeus with vestigial median anterior tooth, in the form of a bluntly pointed low tumosity.

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

3. Eyes with maximum diameter ranging from 0.02 mm t o almost 0.04 mm, with 3-5 rather indistinct facets; their anterior borders situated about 0.87 X the distance from lateral occipital border to midpoint of anterior genal border.

4. Scapes almost exactly attaining median occipital border-in smaller specimens they may fail to do so by a very slight margin (less than 1/4 their maximum thickness).

5. Dorsal mesometanotal suture never distinctly incised, although in several specimens it is represented by a shallow broad transverse impression. Lateral mesonotal suture distinctly marked. Sides and declivitous face of propodeum almost straight in dorsal view. Posterolateral corners of propodeum slightly raised, forming angles of about 90° when viewed from above.

6. Erect to sub-erect pilosity sparse on mandibles, clypeus, frontal lobes, dorsa of mesosoma and node, and entire gaster; more sparse on front of head and more abundant on gaster. Distinct whitish adpressed pubescence everywhere abundant.

7. The holotype and Mann's Waiyanitu specimen are rich medium reddish brown in color. They may possibly have been semi-callow when taken, or else affected by preservation, as the remaining material is darker. The Nandarivatu examples are uniformly very dark reddish brown, with mandibles, antennae, legs, and gastric apex a bright rich yellowish brown.

Queen
Taylor (1967) - A single alate specimen collected with workers at Nandarivatu (my accession no. 35) has the following characters: HL 0.65 mm; HW 0.54 mm; SL 0.49 mm; CI 83; SI 91; PW 0.49 mm; PNL 0.22 mm; PH 0.47 mm; DPW 0.40 mm; PNI 82; maximum diameter of eye 0.18 mm; ocular index 33. Conforming to the general plan of queen structure for the genus. Wing venation of the Ponera coarctata type. Differing from the workers in the usual characters of full sexuality, and agreeing with them in color, sculpturation and pilosity. The median clypeal denticle is reduced to an indistinct low tumosity as in the workers. When laid back along the head the scapes almost exactly reach the median occipital border.

Type Material
Taylor (1967) - Waiyanitu, Viti Levu, Fiji Is. (holotype examined-).

References based on Global Ant Biodiversity Informatics

 * Dlussky G.M. 1994. Zoogeography of southwestern Oceania. Zhivotnoe naselenie ostrovov Iugo-Zapadnoi Okeanii ekologo-geograficheskie issledovanii 48-93.
 * Mann W. M. 1921. The ants of the Fiji Islands. Bull. Mus. Comp. Zool. 64: 401-499.
 * Santschi F. 1928. Fourmis de îles Fidji. Revue Suisse de Zoologie 35: 67-74.
 * Sarnat Eli M. 2009. The Ants [Hymenoptera: Formicdiae] of Fiji: Systematics, Biogeography and Conservation of an Island Arc Fauna. 80-252
 * Taylor R. W. 1967. A monographic revision of the ant genus Ponera Latreille (Hymenoptera: Formicidae). Pacific Insects Monograph 13: 1-112.
 * Ward, Darren F. and James K. Wetterer. 2006. Checklist of the Ants of Fiji. Fiji Arthropods III 85: 23-47.
 * Wheeler W.M. 1935. Check list of the ants of Oceania. Occasional Papers of the Bernice Pauahi Bishop Museum 11(11):1-56.
 * Wheeler, William Morton.1935.Checklist of the Ants of Oceania.Occasional Papers 11(11): 3-56
 * Wilson E.O. 1959. Adaptive shift and dispersal in a tropical ant fauna. Evolution 13(1): 122-144.
 * Wilson E.O., and G.L. Hunt. 1967. Ant fauna of Futuna and Wallis islands, stepping stones to Polynesia. Pacific Insects 9(4): 563-584.
 * Wilson Edward O. 1959. Adaptive Shift and Dispersal in a Tropical Ant Fauna. Evolution 13(1): 122-144
 * Wilson, Edward O. and George L. Hunt. 1967. Ant Fauna of Futuna and Wallis Islands, Stepping Stones To Polynesia. Pacific Insects. 9(4):563-584.
 * Wilson, Edward O. and Hunt, George L. Jr. 1967. Ant Fauna of Futuna and Wallis Islands, Stepping Stones to Polynesia. Pacific Insects. 9(4):563-584