Influence of human activities on the distribution of ants of the genus Messor in Pyrénées-Orientales (Hymenoptera: Formicidae: Myrmicinae). - Based on the distribution of the genus Messor in Pyrénées-Orientales (France), a study of the distribution and geographical structure of the genus is presented, accompanied by a discussion of the process of dispersal over the ages. These ants have a diet strictly composed of seeds, the availability of which influences their establishment. A link between the historical development of human agriculture, characterized by concomitant displacement of cultivated and messicole plants, and the geographic distribution of Messor ants is suggested in this study.