Polyrhachis esarata

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Polyrhachis esarata
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Myrma
Species group: militaris
Species: P. esarata
Binomial name
Polyrhachis esarata
Bolton, 1973

Polyrhachis esarata casent0903457 p 1 high.jpg

Polyrhachis esarata casent0903457 d 1 high.jpg

Specimen Labels

The type specimens were obtained from a fogging sample.

Identification

Rigato (2016) - A medium sized militaris group species very similar to Polyrhachis decellei and separated by the latter mostly because of its comparatively larger and elliptical eyes in profile, and shorter scape (SI < 170 vs. SI > 170).

Polyrhachis esarata was described from a single worker. I consider as conspecific with it one worker and one gyne from Dem. Rep. of the Congo and Equatorial Guinea, respectively. The worker is a little larger than the holotype and lacks the distinctive couple of hairs on the head dorsum, but the corresponding hair pits are present. Also, the eyes are only moderately convex and not strongly protruding as in the type.

Bolton (1973) - This species, a member of the complex of species surrounding Polyrhachis concava and including Polyrhachis alluaudi and its allies, is closest related to Polyrhachis decellei. It may immediately be separated from concava and the more “normal” forms in the complex by the presence of a single pair of erect hairs on the dorsum of the head. This character is shared only with decellei, from which it can be separated by the shape of the anterior clypeal margin, the construction of the petiole and the outline shape of the propodeal margination seen in dorsal view.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Democratic Republic of Congo, Equatorial Guinea, Ghana (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.

  • esarata. Polyrhachis esarata Bolton, 1973b: 303, figs. 45, 55 (w.) GHANA.

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

Description

Worker

Holotype. TL 7.2, HL 1.56, HW 1.20, CI 77, SL 1.91, SI 159, PW 1.08, MTL 1.92.

Anterior clypeal margin arcuate and entire. Eyes convex and protuberant. Sides of head in front of the eyes almost straight, very gently convex and somewhat convergent anteriorly. Behind the eyes the sides of the head round into the broadly convex occipital margin. Alitrunk marginate throughout its length, interrupted only at the sutures. Dorsal surfaces of pronotum and mesonotum flat, dorsal surface of propodeum convex. Pronotum armed with a pair of spines, the outer edges of which are continuous basally with the margination of the segment. Propodeum with a pair of minute, tuberculiform teeth. Promesonotal suture distinct; metanotal groove developed and impressed. In dorsal view the marginations of the alitrunk are convergent posteriorly on the pronotum and mesonotum. On the propodeum the marginations are convex, broadest at about the midlength of the segment and converging anteriorly towards the metanotal groove and posteriorly towards the propodeal teeth where they are terminated. Petiole with a dorsal pair of spines and a lateral pair of small teeth. The dorsal spines are weakly divergent and somewhat back-curved. Anterior face of first gastral segment not concave medially.

Erect hairs present on the anterior clypeal margin and the gastral apex, and with a single pair on the dorsum of the head, situated on a level with the posterior borders of the eyes, behind the posteriormost extension of the frontal carinae. Pubescence dense on alitrunk, long, with a pale brassy tint on the dorsum, rather more greyish on the sides. On the head, gaster and appendages the pubescence very short, fine, greyish in colour and moderately dense.

Sculpturation everywhere of a fine, dense reticulation.

Colour black, the legs, especially the tibiae, very dark brown-black. Palpi and extreme tip of apical funicular segment of antenna yellow-brown.

Rigato (2016) - Worker. HL 1.65, HW 1.30, CI 79, SL 2.13, SI 164, FW 0.38, FI 29, PW 1.08, WL 2.27, HTL 2.19.

Queen

Rigato (2016) - Gyne. HL 1.72, HW 1.40, CI 81, SL 2.08, SI 149, FW 0.42, FI 30, ScW 1.57, MnL 1.97, WL 2.87, HTL 2.34.

Type Material

Holotype worker, GHANA : Eastern Region, Bunso, by pyrethrum knock-down (sample B.3/8), 7.vii.1969 (D. Leston) (The Natural History Museum).

References