Ponera selenophora

A rainforest species that has most commonly been found in leaf litter.

Identification
Taylor (1967) - Apparently widespread in lowland forested areas. Not referable to any species group recognized here, but close to Ponera alpha. The following characters are diagnostic: size moderately large (head width 0.59-0.65 mm). Head broad (cephalic index 88-92), with a more or less distinct median clypeal tooth and small eyes (2-3 indistinct facets); scapes exceeding median occipital border by up to 0.5 X their maximum thickness, antennal club not segmentally differentiated. Mesometanotal suture weakly incised, absent in some specimens. Propodeal and petiolar node structure much as in alpha, the node narrower (petiolar node index 85-89), and the subpetiolar process larger.

P. selenophora is essentially a smaller version of P. alpha, with proportionately shorter scapes, and a narrower petiolar node. In selenophora the petiolar node is of almost exactly the same general (primitive?) plan as that of alpha, with distinct anterolateral and posterodorsal faces, separated by a curving angulate border.

Distribution
Known from Australia, Borneo (Malaysia and Indonesia) and New Guinea.

This taxon was described from New Guinea.

Biology
It is probably significant that all records of selenophora are from low elevations. Wilson took it at the Brown River and Karema sites in primary rain forest. I did not encounter selenophora during almost 5 weeks collecting in New Guinea, but all but a few days were spent at much greater elevations. Considering known facts regarding the zoogeography of Pacific ants, selenophora will probably be more widespread in E. Melanesia. (Taylor 1967)

Castes
Queen, male and immature stages unknown.

Nomenclature

 *  selenophora. Ponera selenophora Emery, 1900c: 317, pl. 8, figs. 4-6 (w.) NEW GUINEA. Combination in Selenopone: Wheeler, W.M. 1933g: 21; in Ponera: Wilson, 1957b: 382. See also: Taylor, 1967a: 41.

Worker
Taylor (1967) - My present concept of P. selenophora may be too extensive. A complex of 2 or 3 closely related species may be represented in the material studied here. The only known New Guinean specimens, apart from the types, are those used by Wilson; I have not seen them all, however, I have seen 2 workers (one an extreme callow) from Karema, Brown River, SE New Guinea, and single workers from the lower Busu River, NE New Guinea, and Skull Creek, N. Queensland, Australia. The Karema specimens were compared with Emery's syntypes of selenophora by Wilson in 1955.

These specimens all seem referable to a single species, although they vary in the development of the mesometanotal suture, and intensity of the sculpturation, particularly on the mesosomal dorsum. The 3 collection localities are widely separated, but it seems that a single, variable species is represented here. In any case it would be presumptuous to name these forms as distinct species at present ; future collecting in lowland forests III New Guinea and Cape York should clarify their true relationships.

The following notes and qualifications are additional to those of Wilson (1957).

1. Dimensions for the New Guinea material are: HL 0.65-0.69 mm; HW 0.59-0.63 mm; SL 0.52 mm; CI 88-92; SI 82- 89; PW 0.45-0.49 mm; PNL 0.23-0.24 mm; PH 0.45-0.46 mm; DPW 0.40-0.42 mm; PNI 85-89. The Skull Creek specimen is slightly larger, but does not differ significantly in the major indices: HL 0.70 mm; HW 0.65 mm; SL 0.53 mm; CI 92; SI 82; PW 0.49 mm; PNL 0.25 mm; PH 0.48 mm; DPW 0.42 mm; PNI 86.

2. Mandibular dentition variable. In all specimens 3 large teeth occupy apical 1/2 of masticatory border, and these are followed by a series of large denticles. In the Karema callow the configuration of the denticles is similar to the syntype described by Wilson: "basal half (of border) occupied by two smaller teeth, one located midway between the basalmost of the apical teeth and the basal angle. In addition there are several irregular denticles in the inter-dentary spaces of the basal half of the border." This general plan is present in the other Karema specimen, but the posterior tooth/denticle series is much less irregular — it consists of 5 large denticles. The Busu specimen agrees with this last Karema one, and the Skull Creek individual, which has very worn mandibles with only traces of the denticles remaining, seems also to comply.

3. The clypeus of the Karema specimens bears a small (0.02 mm high) but distinct conical median tooth, the Skull Creek example has a short longitudinal carina in the middle of the clypeus; and the Busu River specimen has a slightly stronger carina, which almost traverses the clypeus.

4. The scapes exceed the median occipital border by about O.5 X their maximum thickness in the Karema specimens. In the Busu and Skull Creek ones they barely exceed the border.

5. The mesometanotal suture is almost obliterated on the mesosomal dorsum of the Karem a example, a very faint trace being visible in some lights. The suture is not incised in the Skull Creek specimen, but here there is a distinct sculptural discontinuity between the mesonotum and propodeum. The Busu River specimen has a similar sculptural break, and in addition the suture is weakly incised.

6. The sculpturation is variable. That of the mandibles, head and antennae in the New Guinea specimens is as described by Wilson, the frons of the Skull Creek specimen is similarly densely and coarsely punctate, but the punctures are larger - up to approximately 1.5 X the size of those in the New Guinea examples.

The mesosomal sculpturation in the Karema specimens is relatively light, as described by Wilson. The Busu River specimen has the disc of the pronotum moderately coarsely punctate, the individual punctures about 0.006 mm in diameter, separated by distances averaging a little more than half their maximum diameter; the sides of the pronotum are less heavily punctate than its dorsum, and there is a distinct faint transverse rugosity of the interpunctural surfaces. Mesonotal puncturation similar to that of pronotal disc, but with a distinct, though somewhat effaced, accompanying longitudinal rugosity. There is a distinct sculptural break along the mesometanotal suture, propodeal dorsum being rather finely and sparsely punctate. The sculpturing of the sides of the mesosoma is similar to that of the Karema specimens.

The mesosoma of the Skull Creek specimen is somewhat more heavily punctate than either of the New Guinea ones: pronotum subopaque, with a contiguous cover of shallow punctures about 0.01 mm in diameter. Mesonotum much as in Busu River specimen, slightly more coarsely and densely sculptured; propodeal dorsum slightly more coarsely and closely punctate. The mesonotal-propodeal discontinuity marked.

Type Material
Lemien, near Berlinhafen (Aitape), NE New Guinea

Additional References

 * Emery, C. (1900). Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Publicatio secunda. Természetrajzi Füzetek, 23: 310–338.