The codling moth, Cydia pomonella is a major pest in most pome fruit orchards worldwide. Recently, under the selective pressure caused by an increasing number of chemical treatments the codling moth has progressively developed a reduced insecticide susceptibility primarily to organophosphates (acetylcholinesterase inhibitors), and to insect growth regulators (chitin synthesis inhibitors). Small-scale field trials along with bioassays and biochemical or molecular tests are often exploit to reveal the selection of resistance mechanisms in field, such as target site insensibility and enhanced detoxifying activities. In this vein direct AChE-1 gene sequencing and biochemical analysis (EST, GST and MFO activities) were performed in codling moth populations collected in several Emilia Romagna orchards having pest control difficulties. In all analysed populations, the reduced susceptibility to insecticide treatments seems mainly associated to an increased MFO activity while GST and EST detoxifying pathways are more rarely involved. Moreover electrophoretic profiles, show that EST isoforms may be detected in some OP resistant population. These differences may also occur in GST and MFO families, for which there are no currently available rapid qualitative test. It must be stressed that none of the examined populations possess target-site mutations within AChE-1 sequence. The prevalent metabolic profile emerging from our analyses results in agreement with that found in other European codling moth populations with a reduced susceptibility to pesticide treatments based on alternate use of organophosphates and IGR. Trials were carried out to evaluate the correlations between the laboratory results and the field responses of two codling moth populations.
BIOCHEMICAL AND MOLECULAR MONITORING OF INSECTICIDE RESISTANCE IN CODLING MOTH POPULATIONS COLLECTED IN EMILA-ROMAGNA (ITALY) ORCHARDS / Rivi, Marco; Cassanelli, Stefano; E., Pasqualini; S., Civolani; A., Butturini; M., Boselli; Manicardi, Gian Carlo. - STAMPA. - .:(2010), pp. 33-33. (Intervento presentato al convegno Sustainable protection of friut crops in the Mediterranean area. tenutosi a Vico del Gargano (Fg) nel 12-17 september 2010).