Polyrhachis gibbosa

Identification
A member of the Polyrhachis aculeata species group in the subgenus Myrma

Kohout (2013): Polyrhachis gibbosa differs from the other species of the aculeata complex by the dorsal body surfaces being only partly polished and the mesonotum and propodeum being more distinctly sculptured. The mesosoma also appears somewhat shorter and relatively broad, with the pronotal spines only about as long as the width at their bases and the mesosomal dorsum is highly convex in lateral view. The body is entirely black with rather abundant, silvery, appressed pubescence, notably on the pronotal collar and along the dorsolateral margins and sides of the mesosoma.

Distribution based on Regional Taxon Lists
Oriental Region: Sri Lanka.

Nomenclature

 *  gibbosa. Polyrhachis aculeata var. gibbosa Forel, 1908a: 9 (w.) SRI LANKA. Forel, 1913k: 139 (footnote) (q.). Combination in P. (Myrma): Emery, 1925b: 205. Raised to species: Kohout, 2008a: 258.

Worker
Kohout (2013): Dimensions (syntypes): TL c. 5.85-6.35; HL 1.59-1.62; HW 1.31-1.37; CI 82-84; SL 1.87-1.93; SI 141-143; PW 1.18-1.25; MTL 1.87-1.96 (2 measured).

References based on Global Ant Biodiversity Informatics

 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Forel A. 1909. Études myrmécologiques en 1909. Fourmis de Barbarie et de Ceylan. Nidification des Polyrhachis. Bull. Soc. Vaudoise Sci. Nat. 45: 369-407.
 * Forel A. 1911. Ameisen aus Ceylon, gesammelt von Prof. K. Escherich (einige von Prof. E. Bugnion). Pp. 215-228 in: Escherich, K. Termitenleben auf Ceylon. Jena: Gustav Fischer, xxxii + 262 pp.
 * Forel, A. 1908. Fourmis de Ceylan et d'Égypte récoltées par le Prof. E. Bugnion. Lasius carniolicus. Fourmis de Kerguelen. Pseudandrie? Strongylognathus testaceus. Bull. Soc. Vaudoise Sci. Nat. 44: 1-22
 * Gumawardene, N.R., J.D. Majer and J.P. Edirisinghe. 2008. Diversity and richness of ant species in a lowland wet forest reserve in Sri Lanka. Asian Myrmecology 2:71-83
 * Gunawardene N. R., J. D. Majer, and J. P. Edirisinghe. 2008. Diversity and richness of ant species in a lowland wet forest reserve in Sri Lanka. Asian Myrmecology 2: 71-83.
 * Kohout R. J. 2013. A review of the Polyrhachis aculeata species-group of the subgenus Myrma Billberg (Hymenoptera: Formicidae: Formicinae), with keys and descriptions of new species. Australian Entomologist 40(3): 137-171.