Evaluating efficacy of baited insecticide applications for the olive fruit fly control:A four-year survey on pyrethroid insecticide alpha-cypermethrin

Abstract: The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae) is the only pest of olivecrops that is being managed, area-wide by the Greek Government. The currently adopted pestcontrol scheme is targeting the adult stage via application of baited insecticides. For thesuccessful implementation of the control program, the evaluation of the efficacy of theinsecticides applied is of critical importance. The bioassay protocols employed in this projectprovided insights evaluating the current performance of registered insecticides. Theinsecticide alpha-cypermethrin, was used as a model molecule. We detected low mortalitylevels for alpha-cypermethrin in a range of strains tested and demonstrated that such levelsadversely affect the crop protection provided by the baited applications. The efficacy ofalpha-cypermethrin applications was minimized over time, resulting in less than 19%mortality levels at the RLR in 2017, in all cases. The efficacy levels against the olive fruit flyare highly dynamic and can be altered over time. Therefore, efficacy monitoring has to be acontinuous and consistent process. Expansion of the study to all registered insecticides isessential for the design of rational evidence-based pest management schemes that wouldconsiderably minimize crop damage associated with olive fruit fly infestations.