Polyrhachis orokana
Polyrhachis orokana | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Formicinae |
Tribe: | Camponotini |
Genus: | Polyrhachis |
Subgenus: | Aulacomyrma |
Species: | P. orokana |
Binomial name | |
Polyrhachis orokana Kohout, 2007 |
Nothing is known about the biology of Polyrhachis orokana.
Identification
Kohout (2007) - P. orokana is very similar to Polyrhachis impressa, both featuring almost the same sculpture pattern of the mesosomal dorsum, somewhat posteriorly protracted eyes and the concave anterior face of first gastral segment. However they differ in a number of characters, including the shape of the mesosomal-propodeal dorsum which, in orokana is transverse, distinctly wider than long, while in impressa it is as long as wide. The eyes in orokana are convex and protuberant and fully extend beyond the lateral cephalic outline in full face view. In comparison the eyes in impressa are less convex, somewhat sunk into a shallow concavity in the cephalic sculpture and extend only moderately beyond the cephalic outline. The lateral petiolar teeth in orokana are very small and upturned, while in impressa they are relatively long and curved backwards and upwards. The lateral gaster has distinct, horizontally directed, longitudinal striae in orokana; while in impressa the striae are oblique and directed towards the dorso-anterior margin of the first gastral segment.
Keys including this Species
Distribution
Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea (type locality).
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
Countries Occupied
Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species. |
Estimated Abundance
Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species. |
Biology
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Castes
Images from AntWeb
Worker. Specimen code casent0009239. Photographer April Nobile, uploaded by California Academy of Sciences. | Owned by ANIC, Canberra, Australia. |
Paratype of Polyrhachis orokana. Worker. Specimen code casent0903320. Photographer Z. Lieberman, uploaded by California Academy of Sciences. | Owned by NHMUK, London, UK. |
Nomenclature
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- orokana. Polyrhachis (Aulacomyrma) orokana Kohout, 2007a: 231, figs. 84, 87, 90 (w.) NEW GUINEA.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Description
Worker
TL c. 4.94-5.69 (c. 4.94); HL 1.25-1.31 (1.25); HW 1.00-1.06 (1.03); CI 76-82 (82); SL 1.25-1.28 (1.25); SI 121-125 (1.21); PW 0.87-0.90 (0.870; MTL 1.18-1.22 (1.18) (4 measured).
Anterior clypeal margin arcuate, entire; basal margin very weakly impressed, indicated by hairline break in cephalic sculpture. Frontal triangle indistinct. Frontal carinae relatively short, strongly raised with laminate lobes. Sides of head slightly convex in front of eyes, rounding almost immediately into preoccipital margin behind. Eyes strongly convex, situated well back on sides of head, fully protruding beyond lateral cephalic outline. Mesosoma laterally immarginate with dorsum rounding onto sides in unbroken curve; evenly convex in profile. Pronotal humeri armed with somewhat dorso-ventrally flattened, acute teeth; anterior margins dorsally raised; lateral margins continued obliquely downwards and merging on sides with lateral striae. Promesonotal suture distinct, metanotal groove lacking. Mesonotal and propodeal dorsa fused, distinctly transverse, separated from declivity by distinct transverse ridge terminating laterally in rounded prominences. Petiole with acute dorsal margin terminating laterally in very small, upturned teeth. First gastral segment shallowly concave anteriorly, anterodorsal margin of concavity obtuse, not raised above dorsal face of segment.
Sculpture of head and mesosoma consisting of regularly spaced striae, mostly longitudinal on head, converging anteriorly on clypeus. Striation on pronotal dorsum inversely U-shaped anteriorly, becoming widely V-shaped towards promesonotal suture and continuing obliquely onto sides. Mesonotal and propodeal dorsa with almost semicircular striae, extended obliquely along sides. Petiole shagreened. First gastral segment longitudinally striate laterally and dorsally.
Rather short, erect or curved, silvery and off-white hairs on most dorsal surfaces of body, shortest lining dorsal margin of petiole, longest and yellowish on dorsum and apical gaster. Silvery appressed pubescence on pronotal dorsum forming distinct V-pattern, running diagonally from pronotal humeri towards middle and dispersing before reaching promesonotal suture. Pubescence on mesonotal and propodeal dorsa becoming rather dense and somewhat directed medially; sparse on sides of propodeum, dense posteriorly on propodeal lobes and coxae. Propodeal declivity bordered laterally and dorsally with very fine, short, upward curved pubescence. Petiole and dorsum of gaster with fairy abundant pubescence, not obscuring underlying sculpture.
Black. Antennae, femora, proximal ends of tibiae and first tarsal segment very dark to dark reddish-brown, tibiae and tarsi distinctly light yellow.
Type Material
HOLOTYPE: PAPUA NEW GUINEA, E. Highlands, Orokana, 27.xi.1967, under bark of tree, B. B. Lowery (worker). PARATYPES: data as for holotype (3 workers). Type distribution: holotype in Australian National Insect Collection; 1 paratype each in The Natural History Museum, Museum of Comparative Zoology and Queensland Museum.
Etymology
Named after the locality Orokana in the Southern Highlands Province of Papua New Guinea.
References
References based on Global Ant Biodiversity Informatics
- Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
- Kohout R.J. 2007. Revision of the subgenus Aulacomyrma Emery of the genus Polyrhachis F. Smith, with descriptions of new species (pp. 186-253). In Snelling, R.R., Fisher, B.L. & Ward, P.S. (eds). Advances in ant systematics: homage to E.O. Wilson 50 years of contributions. Memoirs of the American Entomological Institute 80: 690 pp.