Polyrhachis gazelle

The holotype is the only specimen known of this species. It was collected at Mt Sinewit by the late Josef Sedláček, a former field worker and a long-time associate of the Bernice P. Bishop Museum, Honolulu, Hawai’i.

Identification
A member of the Polyrhachis continua species group in the subgenus Myrma

With rudimentary lateral petiolar teeth and more-or-less normally shaped eyes, P. gazelle appears to represent an intermediate form between the P. conops and P. continua complexes. (Kohout 2013)

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

Castes
Sexuals and immature stages are unknown.

Nomenclature

 *  gazelle. Polyrhachis gazelle Kohout, 2013: 19, figs. 3, 6-7 (w.) PAPUA NEW GUINEA.

Worker
Dimensions: TL c. 11.34; HL 2.72; HW 2.02; CI 74; SL 3.88; SI 192; PW 1.71; MTL 4.03. Anterior clypeal margin arcuate; clypeus with poorly indicated, blunt, median carina; clypeus weakly sinuate in profile, posteriorly rounding into shallow basal margin. Frontal triangle distinctly impressed. Frontal carinae sinuate, closely approximate anteriorly with acute, almost vertically raised margins; central area relatively narrow with rather flat frontal furrow. Sides of head in front of eyes diverging anteriorly in weakly convex line before rounding into mandibular bases; behind eyes, sides forming a blunt carina extending towards rather prominent occipital corners. Eyes convex, in full face view exceeding lateral cephalic outline. Ocelli lacking. Pronotal dorsum with long, slender, acute spines that are directed anterolaterally and curve slightly downwards, following lateral outline of mesosomal dorsum; lateral edges of spines acute and continuous with parallel margins of pronotum. Promesonotal suture distinctly impressed laterally; mesonotal dorsum transverse with weakly raised anterior corners; lateral margins shallowly emarginate at midlength before converging into medially flat metanotal groove. Propodeal dorsum with lateral margins subparallel, terminating posteriorly in rather indistinct, minute teeth; dorsum descending into declivity in medially uninterrupted line. Petiole scale-like, only marginally higher than wide, with anterior and posterior faces converging dorsally in virtually straight line; dorsal margin armed with two wide-based and tooth-like, acute spines, with inner margins continuous medially, forming ‘U’-shaped dorsum of segment; lateral margin of petiole below base of each spine with angular prominence. Anterior face of first gastral segment flat with anterodorsal margin widely rounding onto dorsum of gaster.

Mandibles distinctly longitudinally striate with piliferous pits. Clypeus reticulate-punctate; sides of head obliquely, vertex mostly longitudinally, striate. Sculpturation on pronotal dorsum finely reticulate-punctate anteriorly, with reticulae more longitudinally organised towards promesonotal suture. Mesonotal and propodeal dorsa more distinctly longitudinally striate; sides of mesosoma and propodeal declivity reticulate-punctate. Petiole and gaster shagreened.

Mandibles along outer margins and masticatory borders with numerous semierect, golden hairs. Anterior clypeal margin with a few longer setae medially and several shorter setae fringing margin laterally. Several pairs of medium length, golden hairs on clypeus, along frontal carinae and single pair of longer, anteriorly inclined hairs on vertex; no hairs lining lateral cephalic outline in full face view. Antennal scapes, mesosoma, petiole, legs and gaster without hairs, except a few hairs on gastral venter and apex. Whitish, closely appressed pubescence rather scarcely distributed on most dorsal surfaces, more abundant with distinctly reddish tint on gastral dorsum.

Colour. Black; narrow band behind mandibular masticatory border, apical funicular segments, legs, including mid and hind coxae, and gaster medium reddish brown.

Etymology
Named after the type locality, Gazelle Peninsula on New Britain, Bismarck Archipelago.

References based on Global Ant Biodiversity Informatics

 * Kohout R. J. 2013. A review of the Polyrhachis continua species-group of the subgenus Myrma Billberg (Hymenoptera: Formicidae: Formicinae) with keys and descriptions of new species. Australian Entomologist 40(1): 13-46.