Les peuplements de Fourmis et les peuplements d’ Acridiens du Mont Ventoux. III. Les peuplements d’Acridiens

Abstract

The composition of the grasshopper communities was studied and an estimate made of the maximum density of each species during the year : in addition, their ecological and altitudinal amplitudes were described. The adults of some species were found to migrate to areas where they were unable to reproduce, so that the breeding sites are only a part of the total area of distribution. The richness and/or composition of these communities differ between vegetation zones. All the communities have a hierarchical structure and are very varied, but three species are predominant : Chorthippus biguttulus, and (to a lesser extent) Stauroderus scalaris and Myrmeleotettix maculatus. Altitudinal and seasonal changes in the communities are discussed, as is the pullulation of certain species. Temperature is the most important of the environmental features, producing an altitudinal zonation of species and communities (less marked, however, than among the ants). Aridity leads to vertical discontinuities in the ranges of certain species on the southern slope of the mountain.