Polyrhachis stricta

Polyrhachis stricta is known only from two specimens found foraging on the ground and low vegetation at the type locality.

Identification
A member of the penelope species-group in the Polyrhachis subgenus Hagiomyrma. Kohout (2013) - Polyrhachis stricta somewhat resembles Polyrhachis placida as they have similar colour patterns. However, the clypeus in P. stricta is almost straight in lateral view with the basal margin only shallowly impressed, while in P. placida the profile of the clypeus is distintly sinuate and the basal margin deeper. The promesonotal lateral margins in P. stricta are strongly converging posteriorly (PMI >190) with the propodeal spines weakly upturned. In contrast, in P. placida the promesonotal margins coverge less strongly (PMI <168) and the propodeal spines curve downwards from their midlength. The pilosity in P. placida is also distintly longer and mostly silvery with the pubescence somewhat less tidy, notably over the gastral dorsum.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Known only from the worker caste.

Nomenclature

 *  stricta. Polyrhachis (Hagiomyrma) stricta Kohout, 2013: 547, figs. 9C-D (w.) AUSTRALIA.

Worker
(holotype cited first): TL c. 6.35, 5.95; HL 1.65, 1.56; HW 1.31, 1.22; CI 79, 78; SL 1.84, 1.72; SI 140, 141; PW 1.12, 1.09; MW 0.59, 0.56; PMI 190, 195; MTL 2.03, 1.90 (2 measured).

Anterior clypeal margin with denticulate median flange. Clypeus with distinct median margin only very shallowly impressed. Frontal carinae sinuate with narrowly raised margins; central area with rather flat frontal furrow. Sides of head in front of eyes only weakly converging towards mandibular bases; behind eyes, sides widely rounding into convex occipital margin. Eyes convex, in full face view clearly breaking lateral cephalic outline. Ocelli lacking. Pronotal dorsum with humeri bluntly angular; promesonotal lateral margins narrowly raised, distinctly converging posteriorly. Promesonotal suture distinctly impressed; metanotal groove indicated by a notch in lateral margins, indistinct dorsally. Propodeal lateral margins terminating in distinctly divergent, weakly upturned, acute spines; dorsum descending into declivity in weakly convex line. Petiole with a pair of slender, divergent, upturned, acute spines. Anterior face of first gastral segment widely rounding onto dorsum.

Mandibles finely striate with numerous piliferous pits. Head, mesosoma and petiole distinctly and closely, rather uniformly, reticulate-punctate. Gaster finely shagreened.

Mandibles at masticatory and outer borders with curved, golden hairs and closely appressed shorter hairs towards bases. Anterior clypeal margin with several longer setae medially and fringe of shorter setae laterally. Numerous, mostly erect hairs on clypeus and along frontal carinae; distinctly shorter hairs on sides of head and vertex. Dorsum of mesosoma with numerous erect or suberect hairs, hairs on propodeum half as long as greatest diameter of eye. Gaster dorsally and ventrally with numerous posteriorly directed, relatively long, golden hairs. Rather sparse pale golden or silvery, closely appressed pubescence on head and mesosoma, more abundant on meso- and metapleura, propodeal declivity and petiole. Gastral dorsum with rich golden pubescence almost hiding underlying sculpturation; pubescence silvery and less abundant on gastral venter.

Black; mandibles, clypeal flange (except narrow anterior margin), antennae, pronotal collar, legs, including coxae, light to medium reddish-brown; tibiae and gastral venter distinctly darker reddish-brown.

Etymology
Derived from the Latin strictus, meaning drawn together, tight, in reference to its distinctly posteriorly constricting promesonotal dorsum.

Determination Clarifications
Polyrhachis stricta and Polyrhachis placida were both listed earlier as ‘Hagio 17’ by Kohout (2000: 200).