Toxicities of 11 Insecticides to Helicoverpa armigera (Hübner) in Laboratory

Toxicities of 11 insecticides from seven different classes to the 3rd-instar larvae of cotton armyworm Helicoverpa armigera(Hubner),collected from Tai'an of Shandong province were measured using leaf dipping method in the laboratory. The results showed that there existed some differences among toxicities of 11 insecticides to test insect. Emamectin benzoate,chlorantraniliprole and flubendiamide had the highest toxicity with LC50 of 0.06~4.94 mg/L,and spinosad,indoxacarb,chlorpyrifos and chlorfenapyr had a moderate LC50 value of 10.00~61.21 mg/L,and methomyl,methoxyfenozide and tebufenozide had low toxicity,and alpha-cypermethrin had the lowest toxicity with LC50 of 506.22 mg/L. Therefore,it was suggested that the conventional insecticides should be replaced with new insecticides which had novel mechanism of action and high efficacy in integrated control of Helicoverpa armigera(Hubner),and meanwhile the new insecticides should be applied reasonably in order to inhibit the development of Helicoverpa armigera(Hubner)resistance to insecticides.