To Evaluate the Efficacy of Different Insecticides on Reduction of European Corn Borer, Ostrinia nubilalis Hubner., Damage in Moghan Region

European corn borer, Ostrinia nobilalis (Hubner), is one of the most important pests of corn which causes economic losses annually. To compare the efficacy of some customary insecticides with new insecticides against the European corn borer current research was undertaken in a randomized complete block design with 9 treatments and in 3 replications. Treatments included eight insecticides namely Pyridalyl (EC 50%), spinosad (SC 24%), indoxacarb (EC 15%), deltamethrin (EC 2.5%), thiodicarb (DF 80%), Bt (Fanavar Zyst Mehr Asia Co.), Bt (S.A. Ctra. Madrid Co.), chlorpyriphos (EC 40%) and a check without spraying. Samplings were carried out one day before and 3, 7 and 14 days after spraying by counting the number of live larvae and bores on corn stems. The results show that spinosad with maximum efficacy (83.8%) was the best treatment against European corn borer. Pyridalyl, indoxacarb and thiodicarb were in second place with 67.15%, 66.23% and 64.93% efficacy, respectively, on both the generations. Mean comparison of number of bores on 10 plants showed minimum numbers in spinosad (6) and pyridalyl (10.33) treatments which are significantly different from deltamethrin (22) and chlorpyrifos (24) treatments. It is concluded that spinosad with maximum efficacy could be recommended to be used against European corn borer and pyridalyl, indoxacarb and thiodicarb could be in second rank. Moreover Bt with acceptable efficiency could be used in IPM programs of this pest.