Polyrhachis fissa

Bolton (1973) - P. fissa is arboreal, workers usually being found running on the trunks of trees. The species appears to be restricted to forests and according to Wheeler (r922a : 269) the nests are composed of vegetable particles and silk and are constructed between two adjacent leaves, which are gummed together to form the walls of the nest.

Identification
A member of the Polyrhachis militaris species-group.

Bolton (1973) - The closest relative of this species is Polyrhachis lauta, from which it may be distinguished by the direction of the propodeal sculpturation and the presence of a facial groove and pit in lauta, which is situated close to the antennal insertion.

Arnold's subspecies Polyrhachis ugandensis, which was described from a single specimen, is one of the more lightly sculptured individuals of this species.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Congo, Democratic Republic of Congo, Gabon, Ghana, Uganda.

Biology
Alates have been collected in Ghana in June and November (Bolton 1973).

Nomenclature

 *  fissa. Polyrhachis fissus Mayr, 1902: 301 (w.q.) CAMEROUN. Combination in P. (Myrma): Wheeler, W.M. 1922a: 995. Senior synonym of bequaerti, ugandensis: Bolton, 1973b: 304.
 * bequaerti. Polyrhachis (Myrma) bequaerti Wheeler, W.M. 1922a: 267, fig. 76 (w.) DEMOCRATIC REPUBLIC OF CONGO. Santschi, 1923e: 294 (q.). Junior synonym of fissa: Bolton, 1973b: 304.
 * ugandensis. Polyrhachis (Myrma) fissa subsp. ugandensis Arnold, 1954: 294, fig. 6 (w.) UGANDA. Junior synonym of fissa: Bolton, 1973b: 304.

Worker
Bolton (1973) - TL 5.2-6.3, HL 1.29-1.74, HW 1.26-1.64, CI 94-97, SL 1.33-1.74, SI 100-115, PW 0.96-1.22, MTL 1.26-1.59. (20 measured.)

Anterior clypeal margin arcuate, entire. Eyes convex, the sides of the head in front of the eyes straight to weakly convex, converging anteriorly; occipital margin convex. Alitrunk marginate throughout its length, the margination interrupted at the sutures. Pronotal spines acute, subtriangular in shape, very broad at the base; their lateral margins more or less straight and continuous with the pronotal margination. Pronotum usually transversely convex on the disc, passing through a slight concavity at the bases of the spines. Propodeum armed with a pair of short, upcurved teeth. Promesonotal suture distinct, transverse, very slightly or not at all arched. Metanotal groove well developed and deeply impressed. In lateral view the propodeum rises almost vertically from the groove, passes through a narrow convexity above and then slopes strongly towards the spines. In dorsal view the propodeal marginations diverge posteriorly. Petiole with four spines, usually of almost equal length, the dorsal pair slightly shorter than the lateral. All the spines are curved posteriorly. Middle of anterior face of first gastral segment concave to receive the convex posterior face of the petiole.

Standing hairs usually present on all dorsal surfaces but may be absent from the first gastral tergite and are always absent from the antennal scapes. At the extreme apex of the scape a few hairs are usually present, projecting in line with the long axis of the shaft. Hairs white to grey-white; pubescence greyish, very sparse.

Sculpturation variable. Clypeus, head in front of the eyes, and the gaster finely superficially reticulate and polished. Head above and behind the eyes either similar to the above or finely and densely longitudinally striate-rugose. Dorsum of the pronotum and mesonotum longitudinally striate-rugose, varying in intensity from finely to deeply incised. Dorsum of propodeum transversely striate, the striae deeply incised and distinct.

Colour black, the gaster distinctly shining. Antennal funiculae usually lighter, brown to yellow-brown. Legs varying from black to yellow-brown, often with the tibiae lighter in colour than the femora.

Queen
Bolton (1973) - As worker, with the usual differences associated with the caste. The spines of the pronotum and petiole, and the propodeal teeth tend to be less well developed than in the worker.

Type Material
Bolton (1973) - Syntype workers and queen, CAMEROUN : Victoria (Buchholz) (NM, Vienna).

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1954. New Formicidae from Kenya and Uganda. Annales du Musée Royal du Congo Belge. Nouvelle Série in Quarto. Sciences Zoologiques. 1: 291-295.
 * Bernard F. 1953. La réserve naturelle intégrale du Mt Nimba. XI. Hyménoptères Formicidae. Mémoires de l'Institut Français d'Afrique Noire 19: 165-270.
 * Bolton B. 1973. The ant genus Polyrhachis F. Smith in the Ethiopian region (Hymenoptera: Formicidae). Bulletin of the British Museum (Natural History). Entomology 28: 283-369.
 * Fisher B. L. 2004. Diversity patterns of ants (Hymenoptera: Formicidae) along an elevational gradient on Monts Doudou in southwestern Gabon. Memoirs of the California Academy of Sciences 28: 269-286.
 * IZIKO South Africa Museum Collection
 * Majer J. D. 1976. The ant mosaic in Ghana cocoa farms: further structural considerations. Journal of Applied Ecology 13: 145-155.
 * Medler J. T. 1980: Insects of Nigeria - Check list and bibliography. Mem. Amer. Ent. Inst. 30: i-vii, 1-919.
 * Robson Simon Database Polyrhachis -05 Sept 2014
 * Stitz H. 1910. Westafrikanische Ameisen. I. Mitteilungen aus dem Zoologischen Museum in Berlin 5: 125-151.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. II. The ants collected by the American Museum Congo Expedition. Bulletin of the American Museum of Natural History 45: 39-269.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004