Biochemical, molecular and field monitoring of insecticide resistancein codling moth populations collected in Emilia Romagna (Italy) orchards

Abstract: Codling moth populations from Emilia-Romagna orchards with difficulties in pestcontrol have been studied combining biochemical and molecular tests, bioassays and small scalefield trials. Biochemical assays aimed to evaluate EST, GST and MFO activities, put in evidencethat the field populations examined have mainly developed a MFO detoxifying response, in somecases supported by EST and/or GST contributes. A direct sequencing strategy of the AChE-1gene showed that none of the analyzed strains possessed target-site mutations within AChE-1sequence. Field trials and bioassays revealed that increased MFO was frequently associated to areduction of IGR sensibility (tebufenozide and diflubenzuron) and, in less extend, to chlorpyrifos.