Les tiques du massif central (france). 1. Les Ixodides (acariens, Ixodoidea) parasites de carnivores et d ongules domestiques sur la bordure orientale du massif - The combined usage of two methods of investigation (collection of ticks on the vegetation by dragging flannel blankets; collection on hosts) has allowed the identification of eight species of the Ixodidae infesting Carnivora and Ungulata, on the eastern border of the Massif Central (France). Each of the species identified on this ter.ritory presents a particular type of distribution, linked to its particular ecological requirements. The authors have attempted to specify several of the factors which govem this distribution. The communities of plants which characterize the Ixodidae biotopes give a general idea of the required ecological conditions (climatology and lithology). In the present works, the vegetation series was taken as the reference unit. Any supplementary information was obtained by the use of the data provided by a network ofmeteorological stations. Rhipicephalus turanicus is confined to regions subject to a Mediterranean climate. Haemaphysalis punctata finds its optimal conditions in the supramediterranean level (Submediterranean series of pubescent oak). The species which has the widest distribution is Dermacentor marginatus which is very widely spread through the mediterranean, supramediterranean and hill levels, but does not penetrate into the damp montane level (Beech and beech-fir seri~s). D. reticulatus is essentially linked to the series of the hill leve! but has a tendancy to infiltra te into the supramediterranean level. Lastly Ixodes ricinus is the only hilly species to penetrate into the series of the damp montane level. Several indications are given concerning human and animal illnesses the distribution of which is linked to that of the tick vectors (Lyme disease, Boutonneuse fever, Babesiosis ... ).