Description and biogeographical implications of a new species of the genus Podisma Berthold 1827 from Mont Ventoux in South France (Orthoptera: Acrididae)

The status of the genus Podisma Berthold 1827 is discussed and all its taxa are listed. Endemic taxa within montane orthopteroid insects in southern Europe are considered and new genera recently revised are recorded. In this context Podisma amedegnatoae n. sp. from Mount Ventoux in the South Alps (France) is defined and described. The main distinctive characters of the new species are the relative length of prozona and metazona, the presence of the dotted dorsal pattern (FDDP) in almost 100% of the females, the broadly incised male furcula, the subquadrate dorsal valvae of the penis and the peculiar v-shaped middle incision diving them. The presence of a distinct species on Mount Ventoux allows to suppose the presence of a refuge area in this region during the ice ages. The analysis of the distribution of the FDDP character, distributed from southern France to southeastern Italy, shows a clear interruption in the genetic flow between the western and eastern slopes (French and Italian slopes) in the western Alps. This interruption fits well with the presence of a hybrid zone, recorded in literature for the genus Podisma on the basis of the distribution in this area of two male sex-chromosome forms. On the other hand data concerning the distribution of FDDP suggest a genetic flow coming from Nortwest to South-east. After that the description of P. amedegnatoae is not only a new contribution to the knowledge of the biodiversity in the southern Europeanmountains but adds new data to the study of the colonisation of Europe after the ice ages, by species which have survived in refuge areas. © 2007 Taylor & Francis Group, LLC.