Polyrhachis mellita

Specimens have been collected in fogging samples from agroforest between 815-920 m elevation.

Identification
A member of the Polyrhachis schnag species group.

Kohout (2008) - Polyrhachis mellita is relatively similar to Polyrhachis leviuscula, described from Singapore. However, while the head and pronotal dorsum are very smooth and highly polished in P. leviuscula, they are finely sculptured in P. mellita. The pronotal dorsum in lateral view is evenly convex in P. leviuscula, while it is distinctly flatter in P. mellita. The anterior face of the petiole in P. mellita is very low and, in lateral view, rounds smoothly onto its dorsum, forming a continuous plane with the petiolar spines. In contrast, the anterior face of petiole in P. leviuscula is higher and more angular in lateral view, with spines arising from petiolar dorsum at a distinct angle. The available specimens of P. leviuscula (including a syntype) are somewhat smaller (HL <1.62) than P. mellita (HL > 1.62) and are more yellow-orange in colour compared to the distinctly lighter, uniformly yellow P. mellita.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Sulawesi.

Castes
Known only from the worker caste.

Nomenclature

 *  mellita. Polyrhachis mellita Kohout, 2008a: 289, figs. 11A-B (w.) INDONESIA (Sulawesi).

Worker
(holotype cited first): TL c. 7.00, 6.40-7.51; HL 1.75, 1.62-1.84; HW 1.28, 1.15-1.31; CI 73, 70-72; SL 2.62, 2.31-2.71; SI 205, 207-214; PW 0.97, 0.69-0.90; MTL 2.68, 2.34-2.90 (10 measured).

Anterior clypeal margin with rather narrow, widely emarginate median flange, flanked laterally by distinct, acute denticles. Clypeus in profile only very weakly convex, rounding posteriorly into moderately impressed basal margin, laterally margin indicated by a thin line. Frontal triangle weakly indicated. Frontal carinae with raised margins sinuate anteriorly, parallel posteriorly; central area concave with poorly indicated frontal furrow. Sides of head in front of eyes converging in virtually straight line into mandibular bases; behind eyes sides strongly converging into rather narrow occipital margin. Eyes convex, in full face view clearly breaking lateral cephalic outline. Pronotum with lateral margins indistinct; mesonotum laterally marginate, margins strongly raised dorsally, forming elevated ridges. Propodeum with lateral margins narrowly raised anteriorly, weakly converging and terminating posteriorly in elevated, dorsally rounded angles; propodeal dorsum descending into steep declivity in medially uninterrupted curve. Petiole with a pair of relatively long, slender, only weakly diverging lateral spines with dorsal margin between them concave. Anterior face of first gastral segment widely rounding onto dorsum.

Mandibles finely reticulate-rugose at bases; sculpture distinctly finer and polished towards masticatory borders. Head, mesosoma and gaster very finely shagreened; intensity of sculpturation increasing posteriorly and laterally, with mesonotal and propodeal dorsa, sides of mesosoma and petiole distinctly reticulate-punctate.

Mandibular masticatory borders with numerous, semierect, golden hairs and numerous very short appressed hairs towards bases. Anterior clypeal margin with long median seta and numerous short setae lining margin laterally. A few paired short, erect hairs near anterior and basal clypeal margins and along frontal carinae. Gaster with numerous, relatively long, erect hairs lining margins of ventral segments and fringe of hairs at gastral apex. Extremely short, closely appressed, golden pubescence in various densities over all dorsal body surfaces.

Colour. Body uniformly yellow, with a light brownish tint in some specimens. Antennae and legs yellowish-brown. Masticatory borders, inner mandibular margins, frontal carinae, pronotal collar, lateral margins of mesonotal and propodeal dorsa and ventral margins of meso-and metapleurae narrowly bordered with dark brown.

Type Material
HOLOTYPE: SULAWESI UTARA: Sulawesi Utara, Dumoga-Bone NP, 400m, 11.ii.1985, fog., N.E. Stork et al. (worker). PARATYPES: data as for holotype (8 workers); ditto, 11.ii.1985 (worker). Holotype and (3) paratypes in, 2 paratypes each in , and.

References based on Global Ant Biodiversity Informatics

 * Kohout, R. J. 2008. A review of the Polyrhachis ants of Sulawesi with keys and descriptions of new species (Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum 52:255-317.