Polyrhachis uncaria

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Polyrhachis uncaria
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Hagiomyrma
Species group: ammon
Species: P. uncaria
Binomial name
Polyrhachis uncaria
Kohout, 2013

Kohout 2013c-40Polyrhachis-uncaria had.jpg

Inhabits open forests and often occurs together with Polyrhachis ammon. The nesting habit of P. uncaria is unknown, but it probably nests in the ground like most other Hagiomyrma species.

Identification

A member of the ammon species-group in the Polyrhachis subgenus Hagiomyrma. Kohout (2013) - Polyrhachis uncaria is very similar to Polyrhachis ammon but they can be separated by the following characters: clypeus in P. uncaria with median carina only weakly raised; clypeus virtually straight in profile, with only a very shallow depression behind anterior margin, terminating posteriorly in an almost flat basal margin; propodeal spines in lateral view directed downwards, following the curved outline of the mesosomal dorsum; petiole with spines subparallel; anterior face of petiole in lateral view rounding dorsally into rather strongly downwardly curved spines; posterior face of petiole distinctly swollen towards base; pubescence on dorsum of head virtually the same density as that on dorsum of mesosoma; very distinct, reddish-golden pubescence covering most of the dorsum of the gaster. In contrast, the clypeus in P. ammon has a distinctly raised median carina and is strongly sinuate in profile with a distinctly impressed basal margin, the propodeal spines are horizontal and aligned with the main axis of the body in lateral view, the anterior face of the petiole is straight and its posterior face is obliquely descending, the petiolar spines are distinctly divergent and horizontal in side view, pubescence is virtually lacking from the dorsum of head which is distinctly black in appearance and strongly contrasts with the pubescent dorsum of the mesosoma, and the reddish-golden patch of appressed gastral pubescence is limited to a median dorsal strip that extends posteriorly from the base of first gastral tergite but does not reach the apex of the gaster.

Keys including this Species

Distribution

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

Biology

Castes

Nomenclature

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

  • uncaria. Polyrhachis (Hagiomyrma) uncaria Kohout, 2013: 523, figs. 4E-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

(holotype cited first): TL c. 8.82, 8.12-8.82; HL 2.15, 2.02- 2.24; HW 1.90, 1.76-1.97; CI 88, 84-88; SL 2.78, 2.52-2.78; SI 146, 141-147; PW 1.68, 1.56-1.76; MW 1.12, 1.01-1.15; PMI 151, 141-158; MTL 3.22, 3.02-3.38 (6 measured).

Anterior clypeal margin with denticulate, medially notched, median flange, laterally flanked by obtuse angles. Clypeus with weakly raised median carina; in profile virtually straight with only very shallow depression anteriorly; basal margin very weakly impressed. Frontal triangle indistinct. Frontal carinae sinuate with moderately raised margins; central area rather flat with shallowly impressed frontal furrow. Sides of head in front of eyes converging towards mandibular bases in weakly convex line; behind eyes, sides rounding into rather low, weakly convex, occipital margin. Eyes convex, in full face view not or only marginally exceeding lateral cephalic outline. Ocelli lacking; relative position of posterior pair indicated by sculptural tubercle in most specimens. Pronotal humeri rounded with raised margins; pronotal lateral margins weakly emarginate or notched at about midlength. Promesonotal suture distinctly impressed. Mesonotum with margins converging towards weakly impressed, medially flat, metanotal groove. Propodeal margins terminating in weakly divergent, somewhat downwards and outwards directed spines. Anterior face of petiole in lateral view rounding dorsally into downward curved spines with distinctly upturned tips. Petiolar spines in dorsal view subparallel with tips curved outwards; posterior face of petiole distinctly convex towards base.

Mandibles very finely, longitudinally striate with numerous piliferous pits. Head, mesosoma and petiole finely and closely reticulate-punctate, sculpture on vertex somewhat more longitudinally directed Spines sculptured at bases, smooth and polished towards tips. Gaster finely shagreened.

Mandibles at masticatory borders with numerous, golden, curved hairs. Anterior clypeal margin with a few, anteriorly projecting longer setae medially and several shorter setae fringing margin laterally. Clypeus, central area and vertex with numerous, medium length, erect and anteriorly directed, golden hairs. Dorsum of mesosoma with numerous, erect or variously curved, golden hairs, some almost as long as greatest diameter of eyes. Several hairs on dorsum of petiole, anterior face of fore coxae and venter of middle and hind coxae and femora. Gaster with abundant, posteriorly directed, golden hairs on dorsum; hairs marginally longer on apex and venter. Closely appressed, medium length pubescence, in various densities over most body surfaces; pubescence silvery on front and sides of head, sides of mesosoma, coxae and petiole, more golden on vertex of head and dorsum of mesosoma where it is medially radiating. Dorsum of gaster with very distinct, reddish-golden pubescence completely hiding underlying sculpturation; pubescence somewhat laterally diffused to more silvery on gastral sides and venter.

Black; mandibles dark reddish-brown towards masticatory borders.

Type Material

Type distribution: Holotype and 1 paratype in Queensland Museum; 2 paratypes each in Australian National Insect Collection, The Natural History Museum and Museum of Comparative Zoology.

References