Lioponera pruinosa

This species is known from a single worker holotype collected in the Cuernos Mountains.

Identification
Brown (1975) - This species is very distinctive because of the extreme reduction of the standing pilosity and the pruinose sculpture-pubescence combination of the main body surfaces. It fits best in the group formerly called Lioponera, but it is larger than longitarsus or Cerapachys luzuriagae|luzuriagae]] and much more densely sculptured than these.

The species described by Wheeler and Chapman as Lioponera bakeri must be similar to pruinosus, judging from the size given (“4 millimeters”) and the very sketchy description, but the type of bakeri was apparently lost in the destruction of the Bureau of Science in Manila during World War II. The description of bakeri reads in part: “Node of petiole as long as high, from above square, truncated in front, transversely rounded behind,” which fits pruinosus passably well, as does “Densely punctured ... Covered with fine recumbent pile.” But “Hairs suberect, scattered, more abundant on scape and abdomen” apparently refers to a somewhat better developed standing pilosity than pruinosus has. Also, “Head coarsely rugose, finer on the remainder of the body,” does not apply to pruinosus. The bakeri type came from Basilan Island, and we shall probably have to await further samples from there before we find out what this species is really like. Incidentally, the bakeri scapes almost certainly do not reach “to the posterior occipital border;” their “fig. 17” shows instead that the authors probably meant to write that the scape reached the posterior border of the eye.

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

Nomenclature

 *  pruinosus. Cerapachys pruinosus Brown, 1975: 71, figs. 51-53 (w.) PHILIPPINES.
 * Combination in Lioponera: Borowiec, M.L. 2016: 164.
 * Status as species: Brown, 1975: 23; Bolton, 1995b: 144.

Worker
Holotype: TL 4.4, HL (to external anterior insertions) 0.75, HW (excluding eyes) 0.69 (CI 92), ML (from insertions) 0.17, scape L 0.45, greatest diameter of eye 0.25, WL 1.14, L petiolar node 0.47, W petiolar node 0.46, L postpetiole 0.58, W postpetiole 0.59 mm.

Form of head and body in dorsal view the petiolar node is a little more nearly square, i.e. with more nearly straight sides. The margin separating the dorsum from the sides of the petiolar node is fine and indistinct, and is best seen in an oblique view from above and to one side.

Mandibular teeth fine, irregular. Mesal genual plates of hind coxae developed as an obtuse-angled lobe on each side.

Dorsal surfaces of head, trunk, petiole, and gaster (except pygidium) very finely and densely punctate, the punctures contiguous on front of head, and very nearly so elsewhere; interspaces or ridges between punctures shining, but so restricted that general surface is opaque to only feebly shining, punctures becoming slightly coarser and a little more widely spaced on lower sides of head, trunk, and gaster (which are therefore more shining), and also on apical gastric segments. Undersides of head and gaster have coarser (but still fine) punctures densely sown on a smooth, shining surface. Mandible, apical half of scapes, forelegs, and mesial surfaces of other legs and pygidium smooth and shining, with sparse punctures. Lateral surfaces of last two pairs of legs and all coxae finely punctate, moderately shining.

The most densely punctate parts of the body (dorsum of head and trunk, petiole, dorsum of gaster, bases of scapes, outer tibial surfaces of last two pairs of legs) covered with fine, short, dense, appressed whitish pubescence that lends a Platythyrea-like, pruinose appearance to much of the upper body surface. The legs, underside of head and especially of gaster with soft, appressed to decumbent pubescence over most sections normally exposed. Longer (but still modest), fine, standing hairs confined to anterior clypeus, mandibles, antennae (especially funiculi), a very few decumbent ones on the tibiae, and a few underneath and at apex of gaster. Color dark brown (piceous).

Type Material
Holotype a unique from J. W. Chapman's Camp (about 1100 m elevation) in the Cuernos Mountains, near Dumaguete, Negros Oriental, Philippines, “5/2/27,” (Chapman). The specimen lacks right anterior and middle legs, left hind leg, most or all of tarsi on the remaining middle and hind legs, and the apical half of the left funiculus, but tibial spurs are present on all the remaining legs.