Revision of the tropical African genus Tetraconcha (Orthoptera: Tettigoniidae: Phaneropterinae) with the description of ten new species.

Only five species of the genus Tetraconcha Karsch, 1890 have been previously known; they inhabit tropical forests of central and western Africa. Generally, specimens belonging to this genus are scarcely represented in museum collections, probably due to the difficulty in finding them, but also for the fragility of their body and legs. During some recent expeditions in the Central African Republic and Ivory Coast it was possible to put together an abundant amount of specimens. This allowed the present author to revise the genus and to find valid characters to distinguish different species. On the whole, ten new species were discovered and the total number now amounts to fifteen species. Interestingly, in the Dzanga-N’Doki National Park (Central African Republic) seven sister species, previously unknown, live together with T. smaragdina; it was possible to separate them by the shape and number of teeth of the stridulatory file under the left tegmen, and later other taxonomical characters were provided. This may be considered a case of evolutionary radiation; that is, Tetraconcha species in the Dzanga-N’Doki National Park evolved traits that primarily linked to sound communication. This radiation very probably occurred randomly, possibly driven by genetic drift.