Mating Disruption of Striped Rice Stem Borer: Importance of Early Deployment of Dispensers and Impact on Airborne Pheromone Concentration

Mating disruption(MD)is an effective environmentally-friendly control method against the striped rice stem borer(RSB),Chilo suppressalis(Lepidoptera:Crambidae).In this study,the current MD dispensers release the pheromone exponentially,with higher initial release rates that decrease throughout the time.To adjust the timing of dispensers'deployment and evaluate the importance of controlling the early first or the second male flight,field trials were carried out to test the efficacy of two strategies:the early dispenser deployment prior to the first male flight(May)and the late deployment prior to the second flight(June).The early dispenser deployment was more effective in reducing plant damage inflicted by RSB when assessed at harvest.However,neither of these strategies was able to inhibit the male catches of the third flight due to the dispensers5 depletion.Attending to the airborne pheromone concentrations obtained,around 1.60 ng/m3 were capable to inhib社C.suppressalis male flight effectively.