Polyrhachis dubia

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Polyrhachis dubia
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Myrma
Species group: revoili
Species: P. dubia
Binomial name
Polyrhachis dubia
Rigato, 2016

Rigato, F hal3.jpg

Rigato, F had3.jpg

Nothing is known about the biology of Polyrhachis dubia.

Identification

Rigato (2016) - A medium-sized species in the revoili-group, with convex anterior clypeal margin, immarginate mesosoma, minute pronotal teeth, very weak propodeal ridges and relatively abundant fine standing hairs on body and appendages.

This is a relatively plain species of the revoili-group, with no clypeal lobe, no mesosomal margination and relatively weak sculpturation. It is similar to Polyrhachis longiseta and differences between them are pointed out under the latter. Polyrhachis lanuginosa is also alike, but has stronger sculpturation, denser pubescence and more yellowish hairs.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (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.

  • dubia. Polyrhachis dubia Rigato, 2016: 16, figs. 3a-c (w.) CAMEROUN.

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

Description

Worker

Holotype. HL 1.47, HW 1.21, CI 82, SL 1.66, SI 137, FW 0.44, FI 36, PW 0.95, WL 1.88, HTL 1.56.

Clypeus ecarinate and with evenly convex anterior margin. Head in full face view oval, with anteriorly converging sides and convex posterior border. Eyes moderately developed and convex. Mesosoma stout, immarginate, in profile more convex anteriorly than posteriorly. Pronotal teeth minute, their anterior edge perpendicular to the longitudinal axis of the body. Propodeal dorsum posterolaterally bearing a pair of weak ridges. Promesonotal suture visible, metanotal suture hardly so. Petiole with a median pair of moderately long, slightly diverging spines and a lateral pair of small teeth. In frontal (or posterior) view the space between the spines evenly shallowly concave. First gastral tergite anteriorly weakly concave.

Mandibles weakly striolate and with sparse piligerous pits. Head, mesosoma and petiole mostly reticulate-punctate. A superimposed irregular rugosity occurs on the head (except clypeus), and a finer, mostly longitudinal irregular rugulosity on the mesosoma. Appendages finely reticulate-punctate and subopaque. Head and mesosoma feebly shining; gaster superficially sculptured and shining.

Standing, pale, thin and flexuous hairs of uneven length are fairly abundant on body and appendages; on average they are slightly shorter on gaster and even shorter on legs and funiculi. Longest hairs on scapes easily surpass maximum scape width, on the tibiae always shorter than maximum tibial width. Pubescence whitish, relatively dense, especially on mesosoma, petiole and gaster; shorter and more regularly arranged on the latter.

Body and coxae black, antennae, mandibles and remaining leg segments mostly ferrugineous. First funicular joint, legs articulations, femora and, above all, tibiae and tarsi infuscated.

Paratypes. (n=6). HL 1.30–1.51, HW 1.13–1.25, CI 83–88, SL 1.57–1.74, SI 138–140, FW 0.40–0.45, FI 35–39, PW 0.81–0.96, WL 1.70–2.00, HTL 1.46–1.66.

Mostly consistent with the holotype. Some variations occur in the degree of darkening of appendages, which, at least partially, keep a ferrugineous or even paler tinge. Smallest specimens lack propodeal ridges and in profile their propodeal dorsum and declivity form a blunt obtuse angle.

Type Material

Holotype. CAMEROUN: Mbalmayo, xi.1993 (N. Stork) (The Natural History Museum, tagged “F.93 C7/44”) Paratypes. same data as the holotype (6 w, BMNH, two specimens per pin: 4 tagged “F.93 C7/47” and 2 tagged “F.93 C7/48”).

References