Polyrhachis wardi

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

Polyrhachis wardi casent0217442 p 1 high.jpg

Polyrhachis wardi casent0217442 d 1 high.jpg

Specimen Labels

Nothing is known about the biology of Polyrhachis wardi.

Identification

Kohout (2007) - P. wardi is a very distinct species separated from other Aulacomyrma by the distinctly laterally widened margins of the propodeal dorsum that extend into short, bluntly terminated, laterally directed teeth.

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 wardi 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

Males have been collected (deposited in ANIC) but have not been described.

Nomenclature

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

  • wardi. Polyrhachis (Aulacomyrma) wardi Kohout, 2007a: 213, figs. 46, 49, 52 (w.q.) 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

Dimensions: TL c. 4.33-5.09 (4.84); HL 1.15-1.34 (1.28); HW 1.00-1.18 (1.09); CI 83-88 (85); SL 1.31, 1.22-1.37; SI 114-126 (120); PW 0.94-1.06 (0.97); MTL 1.12-1.25 (1.18) (11 measured).

Anterior clypeal margin shallowly emarginate medially; clypeus in profile weakly convex with shallow basal margin. Frontal carinae sinuate, with laminate lobes. Sides of head weakly convex, anteriorly converging. Eyes strongly convex, in full face view clearly breaking cephalic outline. Mesosomal dorsum marginate along entire length; weakly convex in profile. Pronotal humeri virtually right-angled, with margins raised. Promesonotal suture distinct. Metanotal groove lacking dorsally, position indicated by emarginations of lateral margins. Propodeal dorsum with lateral margins diverging and extended into rather short, blunt, laterally directed teeth, posterior margins continued as transverse, somewhat incurved ridge, dividing propodeal dorsum from declivity. Petiole with dorsal margin acute, entire, terminating laterally in distinct, backwardly curved spines with weakly upturned tips. First gastral segment concave anteriorly; concavity sharply margined dorsally, but not elevated above dorsal face of segment.

Mandibles irregularly longitudinally striate. Head mostly longitudinally, somewhat irregularly striate-rugose; sculpture more regular on sides; striae originating from below posterolateral corners bowed inwards and then outwards, terminating at bases of mandibles. Striation of mesosomal dorsum longitudinal, anteriorly diverging on pronotum, posteriorly converging on mesonotal-propodeal dorsum, mostly oblique on sides of mesosoma. Petiole with both faces shagreened, some rugosity evident towards sides. First gastral segment mostly shagreened dorsally, sides finely, longitudinally striate.

Rather short, mostly erect, silvery and yellowish hairs on all body surfaces and appendages. Appressed, silvery or greyish pubescence very sparse on head, more abundant on dorsum of mesosoma, curving towards midline, not concealing underlying sculpture; patches of denser pubescence on meso- and metapleuron, coxae and petiole; pubescence fairly abundant on first gastral segment, silvery on sides and richly golden on dorsum, almost hiding underlying sculpture.

Black, including coxae and most of antennal scapes. Apices of scapes, funiculi, mandibular masticatory border, distal portion of femora, proximal ends of tibiae and basal tarsal segments very dark to dark reddish brown. Rest of legs light yellow, almost white in some specimens.

Queen

Dimensions: TL c. 5.84-6.10; HL 1.43-1.47; HW 1.25-1.26; CI 85-87; SL 1.40-1.43; SI 112-113; PW 1.25-1.28; MTL 1.40 (3 measured).

Similar to worker with usual differences associated with caste. Sculpture similar, pattern of striation following fully developed thoracic structure. Pronotal humeri less acute, propodeal teeth less distinct and petiolar spines shorter. Color of body and appendages identical to worker.

Type Material

HOLOTYPE: PAPUA NEW GUINEA, East Sepik Prov., 3km S of Wewak, 03º37’S, 143º37’E, 400m, 15.ii.1989, P. S. Ward #10199 (worker). PARATYPES: data as for holotype (10 workers, 3 alate queens, with some of the specimens not entirely hardened and fully pigmented). Type distribution: holotype, 1 nidoparatype worker and 1 nidoparatype queen in Australian National Insect Collection; 2 nidoparatype workers each in The Natural History Museum, California Academy of Sciences, Museum of Comparative Zoology and Queensland Museum.

Etymology

Named in honor of the collector of the type series, Dr Phil S. Ward.

References