The brown planthopper(BPH), Nilaparvata lugens (st a l),is an important insect pest of rice corps both in tropical and temperate areas in the East and South Asia.Rice damage caused by BPH has become an increasingly serious problem since the 1970s in China.Outbreaks have increased in frequency and the area regularly infested has extended into Jiangsu Province (between the Yangtse and Huaihe Rivers)and even north of the Huaihe River.On average,some 13.3 million hm 2 of the crop are likely to be affected...