Polyrhachis bohemia

Despite of its wide distribution across arid and semi-arid regions of northern tropical Australia, P. bohemia appears to be rare. Like most other Hagiomyrma species, it nests in the ground.

Identification
A member of the schenkii species-group in the Polyrhachis subgenus Hagiomyrma. With its bright red head and mesosoma and dark reddish-brown gaster, P. bohemia is a very charateristic and easily recognised species.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Castes
Known only from the worker caste.

Nomenclature

 *  bohemia. Polyrhachis (Hagiomyrma) bohemia Kohout, 2013: 552, figs. 11A-B (w.q.) AUSTRALIA.

Worker
(holotype cited first): TL c. 6.65, 6.65-7.56; HL 1.62, 1.59- 1.81; HW 1.27, 1.27-1.47; CI 78, 78-81; SL 1.93, 1.87-2.03; SI 152, 138-152; PW 1.22, 1.15-1.43; MW 0.72, 0.64-0.84; PMI 169, 155-181; MTL 2.28, 2.21-2.43 (9 measured).

Median flange of anterior clypeal margin with acute teeth medially, laterally delimited by acute angles. Clypeus with median, rather acute longitudinal carina; straight in profile. Frontal carinae with moderately raised margins; central area relatively wide with blunt, weakly elevated longitudinal carina. Sides of head in front of eyes weakly convex towards mandibular bases; behind eyes, sides rounding into convex occipital margin. Eyes convex, clearly breaking lateral cephalic outline in full face view. Ocelli lacking. Pronotal dorsum distinctly wider than long; humeri widely rounded, weakly concave dorsally with moderately raised margins; lateral margins virtually parallel. Mesonotum with lateral margins weakly converging posteriorly; metanotal groove indistinct dorsally. Propodeal lateral margins divergent, terminating in mostly horizontal, subparallel, acute spines with tips weakly turned outwards in some specimens. Petiole with posterior face distinctly inflated towards base; dorsum armed with pair of horizontal, posteriorly curved, divergent spines.

Mandibles finely longitudinally striate with piliferous pits towards bases. Head, mesosoma and gaster closely reticulate-punctate. Spines distally smooth and highly polished.

Mandibles with medium length, curved, golden hairs near masticatory borders. Only a few, relatively short setae fringing anterior clypeal margin. Numerous relatively long, erect or variously curved, golden hairs arising from all dorsal body surfaces, some hairs almost as long as greatest diameter of eyes. Pale golden and silvery appressed pubescence in various densities over most of body; pubescence most dense and longest on gaster, with rich golden hue dorsally, silvery on gastral venter.

Head and mesosoma light to medium red; gaster distinctly darker, reddish-brown. Mandibular teeth dark brown, legs light to medium brown. Anterior clypeal margin, frontal carinae, lateral margins of mesosoma and spines narrowly bordered with brown.

Queen
TL 7.96; HL 1.78; HW 1.43; CI 80; SL 1.87; SI 131; PW 1.68; MTL 2.31 (1 measured).

Apart from sexual characters very similar to worker, except: pronotal humeri subangular. Mesoscutum almost as long as wide, anterior margin evenly rounded; dorsum flat in lateral view; median line distinct, parapsides rather flat; mesoscutellum flat, only marginally raised above dorsal plane of mesosoma. Propodeal spines distinctly shorter than in worker, horizontal and parallel; propodeal dorsum sloping posteriorly into steeply oblique declivity. Sculpturation similar to worker, sides of mesoscutum and mesoscutellum distinctly finer, almost polished. Pubescence, pilosity and colour scheme virtually as in worker.

Type Material


Type deposition: Holotype and 1 paratype in ; 2 paratypes in ; 1 paratype each in, and.

Etymology
After the type locality, Bohemia Downs, in the southern Kimberley region.

References based on Global Ant Biodiversity Informatics

 * Andersen A. N., J. Lanoue, and I. Radford. 2010. The ant fauna of the remote Mitchell Falls area of tropical north-western Australia: Biogeography, environmental relationships and conservation significance. Journal of Insect Conservation 14: 647-661.
 * Kohout R.J. 2013. Revision of Polyrhachis (Hagiomyrma) Wheeler, 1911 (Insecta: Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum  Nature 56: 487577