The aim of this study was to evaluate suitability of trees for phytoseiid mite development in a framework of integrated pest management. Phytoseiid mite densities and diversity were surveyed on 16 plant species in two arboreta in the South of France. Samplings in the two arboreta were carried out on 5 trees of the same plant during 4 months, twice a month. Within the same arboretum, densities were not significantly different between the 5 replications of the same plant species. However, significant differences in phytoseiid mite densities and diversity were observed between the plants within the two arboreta. In order to determine the factors affecting these differences, foliar characteristics (trichome and domatia densities, domatia structure, pilosity of the vein axils, leaf surface) were evaluated. Multifactorial analysis shows relations between some of these parameters, especially numbers of domatia, density and pilosity on vein axils, and phytoseiid mite densities. Mite diversity was different between plant species but also for a same plant species between the two arboreta. Factors affecting this difference in diversity are discussed.