Polyrhachis pelecta

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Polyrhachis pelecta
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Aulacomyrma
Species: P. pelecta
Binomial name
Polyrhachis pelecta
Kohout, 2007

Polyrhachis pelecta P.jpg

Polyrhachis pelecta D.jpg

Nothing is known about the biology of Polyrhachis pelecta.

Identification

Kohout (2007) - P. pelecta is rather close to Polyrhachis geometrica but differs in having the pronotal teeth broad-based, the lateral propodeal margins feebly dentate posteriorly, the dorsal margin of the petiolar node more-or-less entire and the first gastral segment with very fine striations confined to its sides. In contrast, the pronotal teeth in geometrica are distinctly smaller and more acute, the propodeum smoothly rounds into the declivity, the dorsal margin of petiolar node is distinctly medially emarginate and the whole surface of first gastral segment is distinctly and finely, striate.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (type locality).

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Polyrhachis pelecta for further details

Biology

The subgenus this species is a member of, Aulacomyrma, is poorly colected. Kohout (2007) summarized what is known about their biology in a revision of the species in the subgenus. This offers an explanation as to why most Aulacomyrma are known from few collections and specimens. There are only two records of nests being found. A small colony of Polyrhachis dohrni was collected by Kohout from a dry hollow twig on a living tree at the edge of lowland rainforest. The internal walls of the twig cavity were lined with a little silk. Ward collected a nest of Polyrhachis wardi from a dry twig of a rainforest tree. The colonies of both species were rather small, with only a few workers (5 and 11 respectively, including 2 and 3 alate queens and a single male). If such a nesting pattern is the norm for other species of the subgenus, that might explain the general scarcity of Aulacomyrma material even in the best collections. Many Aulacomyrma species are described and only known from a holotype.

Castes

Known only from the worker caste.

Nomenclature

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

  • pelecta. Polyrhachis (Aulacomyrma) pelecta Kohout, 2007a: 233, figs. 91, 94, 97 (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

(holotype cited first): TL c. 5.49; HL 1.47, 1.43; HW 1.28, 1.28; CI 87, 89; SL 1.50, 1.50; SI 117, 117; PW 1.12, 1.12; MTL 1.43, 1.40 (2 measured).

Anterior clypeal margin arcuate, entire; slightly sinuate in profile. Frontal triangle indistinct. Frontal carinae strongly sinuate, raised, with laminate lobes; central area relatively wide with rather distinct longitudinal carina formed by strongly raised median stria. Sides of head gently convex, only weakly converging anteriorly. Eyes convex, in full face view breaking lateral cephalic outline. Pronotal humeri armed with broad-based triangular teeth, that are shallowly concave dorsally between distinctly raised margins; lateral margins continued for some distance before merging with dorsal striae along sides. Promesosonal suture distinct; metanotal groove lacking. Mesonotal dorsum only partially marginate. Propodeal dorsum immarginate, with posterior angles weakly indicated. Petiole relatively narrow, as wide as high, with dorsal margin somewhat jagged; lateral spines short, slender, directed outwards and only slightly curved backwards. Anterior face of first gastral segment only shallowly concave medially at base.

Sculpture of head consisting of regularly spaced striae; mostly longitudinal, converging medially and anteriorly on clypeus and between frontal carinae. Pronotal dorsum with broadly open, inverse V-shaped striae. Sculpture of mesonotal-propodeal dorsa differing between holotype and paratype; striae in holotype forming incomplete semicircles, open inversely U-shaped posteriorly; in paratype striae strongly converging posteriorly and meeting along midline in V-shaped pattern. Dorsum of first gastral segment microscopically shagreened, becoming finely longitudinally striate towards sides.

Short, erect or semierect, off-white or yellowish hairs present in various densities on most body parts, except inferior edge of antennal scapes. Rather sparse, appressed pubescence everywhere; more dense on coxae and anterior face of petiole and propodeal declivity that is bordered laterally by very short, greyish, semierect fine hairs. Gastral dorsum with light cover of silvery pubescence not concealing underlying sculpture.

Black; antennae and legs dark to very dark reddish-brown. Mandibular masticatory borders, funiculi, tibiae, except proximal ends, and distal tarsal segments distinctly lighter.

Type Material

HOLOTYPE: PAPUA NEW GUINEA, Karubaka, Swart Valley, 03º35’S, 138º30’E, 1500m, 11.xi.1958, J. L. Gressitt (worker). PARATYPE: data as for holotype (1 worker). Type distribution: holotype in Museum of Comparative Zoology; paratype in Queensland Museum.

Etymology

Name derived from the Latin pellax, meaning deceitful or decoy, in reference to its close resemblance to Polyrhachis geometrica.

References