Polyrhachis rutila

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Polyrhachis rutila
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Cyrtomyrma
Species: P. rutila
Binomial name
Polyrhachis rutila
Kohout, 2006

Polyrhachis rutila casent0903421 p 1 high.jpg

Polyrhachis rutila casent0903421 d 1 high.jpg

Specimen Labels

Known only from the type locality with all specimens collected by a single sweep of low foliage along the rainforest edge. (Kohout 2006)

Identification

Polyrhachis rutila is characterised by the outline of mesosoma which has a weakly concave summit and strongly impressed promesonotal suture. The brownish coloration of P. rutila is unlike all the other Australian Cyrtomyrma species that are jet-black. (Kohout 2006)

Keys including this Species

Distribution

Known only from the type locality in Queensland’s wet tropics.

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Abundance

Known only from types.

Biology

Castes

Polyrhachis rutila is only known from (type) workers.

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • rutila. Polyrhachis rutila Kohout, 2006b: 104, figs. 3C, H-I (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. 4.94, 4.89-5.19; HL 1.31, 1.28-1.37; HW 1.31, 1.28-1.37; CI 100, 98-101; SL 1.43, 1.43-1.56; SI 109, 109-117; PW 0.97, 0.90-1.03; MTL 1.75, 1.68-1.81 (9 measured).

Anterior clypeal margin with central flange broadly emarginate medially and flanked by minute denticles. Clypeus in profile straight for most of its length, posteriorly curving abruptly into well impressed basal margin. Frontal triangle indistinct. Frontal carinae rather short, sinuate, with moderately raised margins; frontal furrow represented by more-or-less distinct, weakly raised, longitudinal carina. Sides of head in front of eyes almost straight, strongly converging into mandibular bases; behind eyes sides rounding into convex occipital border. Eyes relatively large, moderately convex, in full face view just reaching lateral cephalic outline. Median ocellus rather obscure, lateral ocelli lacking, relative positions indicated by shallow depressions in cephalic sculpturation. Pronotum in dorsal view with humeri rounded; greatest pronotal width at or near mid-length of segment. Mesosoma in profile with anterior face of pronotum convex; dorsum weakly concave with well impressed promesonotal suture; mesonotum convex; metanotal groove indistinct, indicated in some specimens by rather shallow depression in outline. Petiole with anterior face almost straight, posterior face moderately convex; dorsum armed with four short, acute, subequal teeth. Subpetiolar process acute anteriorly, angular posteriorly. Anterior face of first gastral segment with base weakly concave, narrowly rounding onto dorsum of segment.

Mandibles very finely, mostly longitudinally rugose with numerous shallow punctures and piliferous pits. Head, mesosoma and gaster very finely shagreened, sculpturation on sides of mesosoma and petiole more distinct, reticulate on meso- and metapleurae and both faces of petiole. Rather dense piliferous pits and shallow punctures covering all body surfaces.

Mandibular masticatory borders with a few, rather short, curved hairs. Anterior clypeal margin usually with 1 long and 2 shorter, anteriorly directed setae medially and numerous shorter setae fringing margin laterally with their lengths decreasing towards madibular bases. Several medium length, erect, mostly paired hairs arising near anterior and basal clypeal margins, along frontal carinae, on vertex and around apex of gaster. Hairs virtually absent from mesosoma, petiole and most of gastral dorsum. Very short, mostly appressed or decumbent pubescence arising from pits over all body surfaces, denser patches of more erect hairs on propodeum, petiole and venter of gaster.

Body generally light to medium reddish-brown with sides of mesosoma and petiole distinctly darker. Mandibular masticatory borders, condylae and gaster light yellow. Antennae reddish-brown with distal ends of scapes and apical segments of funiculi distinctly lighter. Anterior and basal clypeal margins, frontal carinae and genal carina narrowly lined with dark brown or black. Coxae and subpetiolar process light reddish-brown. Legs generally light yellow with proximal ends of tibiae and tarsi a shade darker.

Type Material

HOLOTYPE: QUEENSLAND, Davies Ck, c. 17km E of Mareeba, 17°01’S, 145°35’E, 15.vi.1980, rf. edge, R.J. Kohout acc. 80.19 (worker). PARATYPES: data as for holotype (9 workers). Holotype (QMT99340) and 3 paratypes in Queensland Museum, 2 paratypes each in Australian National Insect Collection, The Natural History Museum and Museum of Comparative Zoology.

References