Abstract: 【Aim】 The brown planthopper (BPH), Nilaparvata lugens, is one of the most important pests on rice. The objective of this research is to determine the effects of volatiles emitted from BPH-induced resistant rice varieties (IR64, ASD7 and IR56) on the resistance of the susceptible rice variety TN1, and to provide theoretical and technical guidance for the green ecological control of BPH. 【Methods】 We employed rice-BPH-Anagrus nilaparvatae as a model system. TN1 plants were exposed to the volatiles emitted from rice varieties (IR64, ASD7, IR56 and TN1) uninfested and infected by BPH female adults (BPH-induced rice), respectively, and the number of eggs laid per female, the amount of honeydew secreted per female, nymphal survival rate and egg hatching rate of BPH on TN1 plants were measured. The choice of the female adults of BPH and A. nilaparvatae to the abovementioned TN1 plants was determined by using an H-type olfactometer and a Y-type olfactometer, respectively.【Results】 Exposure of TN1 plants to the volatiles emitted from BPH-induced resistant rice reduced the number of eggs laid per female of BPH, while exposure to volatiles emitted from uninfested resistant rice did not affect the number of eggs laid per female of BPH. Exposure of healthy TN1 plants to the volatiles emitted from BPH-induced IR64 decreased the amount of honeydew secreted per female, but had no effects on the egg hatching rate and nymphal survival rate of BPH. In addition, exposure of healthy TN1 plants to the volatiles emitted from BPH-induced IR64 also reduced the attractiveness to BPH, but enhanced the attractiveness to A. nilaparvatae. When healthy TN1 plants were exposed to the volatiles emitted from BPH-induced IR64 or TN1, only the relative content of 2-heptanone in TN1 plants changed significantly.【Conclusion】 Exposure of TN1 plants to volatiles emitted from BPH-induced resistant rice varieties reduces the number of eggs laid and the amount of honeydew of BPH female adults, reduces the attractiveness to BPH female adults, but enhances the attractiveness to the parasitoid A. nilaparvatae. The relative content of 2-heptanone in TN1 plants is increased when TN1 plants are exposed to the volatiles emitted from BPH-induced resistant rice variety IR64, which may be an important reason to the behavior changes of BPH and A. nilaparvatae.

Key words:  Rice, Nilaparvata lugens, Anagrus nilaparvatae; plant volatiles, neighboring plants, direct and indirect defense responses, resistance