Polyrhachis opacita

Polyrhachis opacita
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Camponotini
Genus:	Polyrhachis
Subgenus:	Campomyrma
Species complex:	gravis
Species:	P. opacita
Binomial name
	Polyrhachis opacita; Kohout, 2013

This species is evidently restricted to Western Australia, with both known specimens collected on a single occasion at Coral Bay.

Identification

A member of the Polyrhachis gravis species-group. Kohout (2013) - Polyrhachis opacita is characterised by the very finely striate, opaque gaster with the carina on anterior margin of the first gastral tergite only poorly developed.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Australasian Region: Australia (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

Castes

Sexuals and immature stages unknown.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

opacita. Polyrhachis (Campomyrma) opacita Kohout, 2013: 102, figs. 4A-B, E-F (w.) AUSTRALIA.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Dimensions (holotype cited first): TL c. 9.52 ,9.78; HL 2.28, 2.31; HW 1.96, 2.06; 086, 89; SL 2.46, 2.50; SI 125, 121; PW 1.81, 1.81; MTL 3.28, 3.22 (2 measured).

Mandibles with 6 teeth. Clypeal margin widely truncate, truncate portion denticulate medially. Clypeus without distinct median carina; straight in profile with flat base. Frontal triangle distinct. Frontal carinae sinuate with moderately raised margins; central area with rather indistinct frontal furrow. Sides of head in front of eyes weakly convex towards mandibular bases; behind eyes sides narrowly rounding into distinct occipital corners. Eyes convex, in full face view clearly breaking lateral cephalic outline. Ocelli lacking. Pronotal humeri bluntly angular; lateral margins of pronotum converging posteriorly towards moderately impressed promesonotal suture. Mesonotal and propodeal lateral margins converging posteriorly in single, weakly sinuate line; metanotal groove flat. Propodeal dorsum strongly narrowed posteriorly with lateral margins terminating in upturned, somewhat dorsomedially flattened teeth; dorsum curving through narrow gap between closely approximate teeth into steeply descending declivity. Dorsum of petiole armed with a pair of slender spines; outer margins of spines descending into distinctly shorter acute, lateral spines. Gaster in lateral view with anterior face flat; anterior margin of first gastral tergite with poorly indicated carina.

Mandibles finely, longitudinally striate with numerous piliferous pits. Head, including clypeus, reticulate-striate. Pronotal dorsum with rather irregular, somewhat obliquely directed striae; mesonotal dorsum longitudinally striate with sculpture on propodeal dorsum rather irregularly rugose. Sides of mesosoma and petiole finely wrinkled. Gaster very finely and closely reticulate-striate, opaque.

Mandibles with numerous, curved, golden hairs; anterior clypeal margin with numerous, relatively long, reddish-golden setae medially and fringe of shorter setae laterally. Numerous, medium length hairs on clypeus; rather abundant, distinctly shorter, bristle-like hairs on rest of head; distinctly less abundant, short, bristle-like hairs, on dorsum of mesosoma and along lateral margins of petiole. Dorsum of gaster with numerous, short, posteriorly inclined hairs, with hairs distinctly increasing in length towards apex; venter of gaster with numerous, medium to rather long, golden hairs. Closely appressed, greyish or silvery pubescence in various densities on most body surfaces, virtually absent from dorsum of mesosoma.

Whole body, including fore coxae and dorsum of gaster black. Mandibles black, with teeth and bases reddish-brown; narrow band along masticatory borders light reddish-brown. Antennae black with only apical funicular segments light reddish-brown. Femora and middle and hind coxae medium reddish-brown; tarsi black. Venter of gaster and apex reddish-brown.

Type Material

Holotype, worker, Coral Bay, Western Australia, Australia, I. & G. Grose, Australian National Insect Collection.
Paratype, 1 worker, Coral Bay, Western Australia, Australia, I. & G. Grose, Western Australian Museum.

Etymology

Derived front the Latin opacus, meaning shady, obscure, in reference to its very finely striate, opaque gaster.

References

Heterick, B.E. 2021. A guide to the ants of Western Australia. Part I: Systematics. Records of the Western Australian Museum, Supplement 86, 1-245 (doi:10.18195/issn.0313-122x.86.2021.001-245).
Heterick, B.E. 2022. A guide to the ants of Western Australia. Part II: Distribution and biology. Records of the Western Australian Museum, supplement 86: 247-510 (doi:10.18195/issn.0313-122x.86.2022.247-510).
Kohout, R.J. 2013. A review of the Polyrhachis gravis and micans species-groups of the subgenus Campomyrma Wheeler (Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum, Nature 56, 92-117.

References based on Global Ant Biodiversity Informatics

Kohout R.J. 2013. A Review of the Polyrhachis gravis and micans species-groups of the subgenus Campomyrma Wheeler (Hymenoptera: Formicidae: Formicinae). Memoirs of the QLD Museum-Nature 56: 92-117