Abstract
Several strains of Nasonovia ribisnigri (Mosley) collected near Perpignan (south of France) and Almeria (south of Spain) were bioassayed and compared with a reference susceptible strain from The Netherlands. Resistance to 5 tested insecticides was observed in 2 strains. The highest resistances recorded were 680-fold for endosulfan, 26-fold for deltamethrin, 62-fold for pirimicarb, 46-fold for methomyl, and. Ii-fold for acephate. These results are discussed in relation to the possible mechanisms of resistance present in the different N. ribisnigri strains and to potential control strategies.