Date of this Version
Environmental Entomology 9:6 (December 1980), pp. 773–777.
Resurgence of the brown planthopper, Nilaparvata lugens (Stål) on rice was induced by applications of decamethrin, methyl parathion, and diazinon. Differential mortality of predators and hoppers did not appear to be the primary factor for resurgence. Hoppers appeared to be attracted to methyl parathion and decamethrin treated plants because of plant growth. Improved plant growth, however, did not compensate for the increased feeding of the insecticide-treated hopper population, and plants treated with resurgence-causing insecticides succumbed to feeding injury earlier than untreated plants. Population increases were due in part to stimulation of reproduction of the hopper, either by contact action of the insecticides or through increased plant growth. Reduction in the length of the nymphal stage and increased adult longevity resulting in a shortened life cycle and longer oviposition period, respectively, were additional factors contributing to resurgence.