Les cochenilles sont des insectes peu connus qui ont pourtant longtemps contribué à notre vie domestique. Toutefois, certaines espèces demeurent aujourd'hui d'importants ravageurs. La lutte biologique semble l'un des moyens de lutte les plus prometteurs.

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.

The composition of the ant communities and the relative frequency of each species are described, as well as their ecological and altitudinal amplitudes. The richness and/or the composition of the communities differs from one vegetation zone to another. All the communities show a very hierarchical structure. The Shannon eaver index of evenness is roughly equal in all communities. The communities are very varied, but three species are predominant over the mountain : Lasius niger, Tetramorium caespitum and Formica lemani. Of the environmental features, temperature is the most important, producing a marked altitudinal zonation of species and communities. The effects of aridity are important among certain species, leading to vertical discontinuities in their ranges. The vegetation cover affects species dependant on particular plants ; these species have been considerably affected by reafforestation, especially on the lower parts of the southern slopes, leading to a notable increase in L. niger. At the summit, the main limiting factor is temperature on the northern slope ; and the dessicating effects of the winds on the southern slopes.