Avant-propos

From several points of view (geographical, biological and hu man), the Mont Ventoux exemplifies many of the problems cur rently facing the limestone areas of Provence. For this reason, a wide range of studies was carried out there between 1972 & 1976, to investigate the climate, vegetation, fauna and certain sociolo gical problems ; these are described in the following articles (except the climatological work, which is not yet complete)

Les peuplements de fourmis et les peuplements d’acridiens du mont Ventoux III. — Les peuplements d’Acridiens

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 distribu tion. The richness and/or composition of these communities differ between vegetation zones. All the communities have a hierar chical structure and are very varied, but three species are predo minant : Chorthippus biguttulus, and (to a lesser extent) Stauro- derus 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 commu nities (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

les peupleuments de Fourmis et les peuplements d'Acridiens du Mont Ventoux. II. Les peuplements de Fourmis

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 : Lasiw; 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 caver 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

La végétation du mont Ventoux

The vegetation map (see Appendix) is based on the concept of the vegetation series, within which different stages (mature forest, pre-climax forest, scrub, grassland and reafforested areas) are recognised. The most important native trees are Quercus ilex, Q. pubescens, Fagus sglvatica, Pinus halepensis, P. sglvestris, P. uncinata and Abies alba. The vegetation contains elements of both the Mediterranean and the Central European phyto-geogra- phical regions. The former is more typical of the southern slope and the lower part of the northern slope ; the latter occurs on the upper part of the northern slope (extending over to the summit of the southern slope) and part of the eastern ridge. Each of the vegetation series is restricted to one subgroup of these two broad divisions. The Mont Ventoux contains most of the vege tation series known from the limestone regions of southern France ; and the combination of a Mediterranean vegetation on the southern slopes with a Central European type on the northern slopes make it a typical example of the southern prealpine mountains

Quelques données sur la biologie des Diptères Bombyliidae

Du Merle Paul. Quelques données sur la biologie des Diptères Bombyliidae. In: Bulletin de la Société entomologique de France, volume 77 (7-8), Septembre-octobre 1972. pp. 190-201

Avant-propos

From several points of view (geographical, biological and human), the Mont Ventoux exemplifies many of the problems currently facing the limestone areas of Provence. For this reason, a wide range of studies was carried out there between 1972 & 1976, to investigate the climate, vegetation, fauna and certain sociological problems ; these are described in the following articles (except the climatological work, which is not yet complete).Du Merle Paul. Avant-propos. In: La Terre et La Vie. Supplément n°1, 1978. Écologie du Mont Ventoux, sud de la France. pp. 7-10

Développement parthénogénétique chez la Tordeuse verte du chêne, Tortrix viridana L. (Lepidoptera, Tortricidae)

Parthenogenesis in the green oak tortrix, Tortrix viridana L. (Lepidoptera, Tortricidae). Eleven sets of eggs laid by virgin Tortrix viridana females of varied origins (6 geographical provenances, 4 species of oaks attacked) were held under conditions themselves varied, continuously natural for two of them. They comprised a total of 10127 eggs. In each case, eggs (4.7-8.6% of the individuals ; 6.4% on average) presented an embryonic development. In each case too, this development continued in some eggs (0.5-2.4% of the individuals ; 1.5% on average) up to the formation of a larva. In total, 13 eggs hatched. The variety of the populations studied suggests that parthenogenesis is a potentiality that characterizes the species T. viridana as a whole. But mortality during embryonic development was high in parthenogenetic eggs, and it is unlikely that parthenogenesis could influence the population dynamics of the tortrix.Onze lots d'œufs déposés par des femelles vierges de Tortrix viridana d'origines variées (6 provenances géographiques, 4 espèces de chênes attaquées) ont été conservés dans des conditions elles-mêmes variées, constamment naturelles pour deux d'entre eux. Ils comportaient au total 10 127 œufs. Dans chaque cas, des œufs (4,7-8,6% des individus ; en moyenne 6,4%) ont présenté un développement embryonnaire. Dans chaque cas, également, ce développement s'est poursuivi chez certains œufs (0.5-2.4% des individus ; en moyenne 1,5 %) jusqu'à la formation d'une chenille. Au total, 13 œufs ont éclos. La variété des populations étudiées suggère que la parthénogenèse est une potentialité caractérisant l'espèce T. viridana tout entière. Mais la mortalité au cours du développement embryonnaire a été élevée chez les œufs parthénogénétiques et il est peu probable que la parthénogenèse joue un rôle dans la dynamique des populations de l'insecte.Du Merle Paul. Développement parthénogénétique chez la Tordeuse verte du chêne, Tortrix viridana L. (Lepidoptera, Tortricidae). In: Bulletin de la Société entomologique de France, volume 104 (1), mars 1999. pp. 85-90

Quelques données sur la biologie des Diptères Bombyliidae

Du Merle Paul. Quelques données sur la biologie des Diptères Bombyliidae. In: Bulletin de la Société entomologique de France, volume 77 (7-8), Septembre-octobre 1972. pp. 190-201