RESISTENZA AGLI INSETTICIDI NEONICOTINOIDI IN POPOLAZIONI EMILIANO-ROMAGNOLE DELL’AFIDE VERDE DEL PESCO

In 2010-2011 in a few peach orchards in Emilia-Romagna some cases of reduced efficacy of insecticide treatments with neonicotinoids against the green peach-potato aphid, Myzus persicae (Sulzer) have been reported. The susceptibility towards imidacloprid in a couple of these population has been studied by bioassays, also applying the synergist piperonyl butoxide (PBO). To detect the mutation conferring “target-site” resistance to neonicotinoid insecticides biomolecular analysis have been used. Bioassays pointed out in the two studied populations resistance factors respectively equal to 12 and more than 600. PBO reduced significantly in both cases the resistance factors suggesting the involvement of metabolic resistance produced by mixed function oxidases. The population with the strongest resistance was also positive to the mutation R81T associated with neonicotinoids resistance. This is the first report for Italy of this resistance mechanism.