Insecticide Resistance and Detoxification Enzymes Activity in Nilaparvata lugens Stål Against Neonicotinoids

The Nilaparvata lugens (Stål) is one of the most destructive pests of rice crops in Asian. To assess the resistance of imidacloprid, thiamethoxam, clothianidin, and nitenpyram, N. lugens exposed to each pesticide up to 15 generations. Results showed that the resistance of N. lugens increased significantly against imidacloprid, thiamethoxam, clothianidin, and nitenpyram (neonicotinoids) under selection pressure. There was a 118.07-fold increase in resistance against imidacloprid, 90.37-fold against thiamethoxam, 217.81-fold against clothianidin, and 34.09-fold against nitenpyram in 15th generation as compared to F0. Based on fold increase, imidacloprid and clothianidin subjected for enzymatic analysis and results showed that enzyme activity involves resistance development against neonicotinoids. Cytochrome P450, esterase, and GST had significantly higher activity as the generation passes under the selection pressure of imidacloprid and clothianidin. There was a significant correlation existed between GST, and esterase activity, when compared to LC50 of imidacloprid. GST, esterase and P450 showed a significant correlation with LC50 of clothianidin. The results showed that detoxification enzymes play an important role in insecticide detoxification. When the mixture of imidacloprid and clothianidin tested results showed that the mortality exerted was similar to control when imidacloprid and clothianidin resistant populations were exposed.