1 National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA), Centre d'Aix-en-Provence, 3275 route Cézanne, 13182 Aix-en-Provence, France. Electronic address: arnaud.sentis@irstea.fr.
2 Université Côte d'Azur, INRA, CNRS, UMR ISA, 06000 Nice, France. Electronic address: nicolas.desneux@inra.fr.