THE APPLICATION OF INDEX OF POPULATION CONTROL (IPC) TO STUDIES ON THE RESISTANCE OF RICE VARIETIES TO THE BROWN PLANTHOPPER,NILAPARVATA LUGENS (Stal)

By means of life tables and the index of population control(IPC) ,rice varielal resistance to the brown planthopper(BPH),Nilaparvata lugens (Stal)was studied in the paddy field. Varieties "Xinghuizhan 1" and "7915 "were indentified as highly resistant (HR ), "Qiguizao 25 "and "Bohuizhan 1" as moderately resistant (MR) ,and"Shuanggui 1 "as susceptible(S)to BPH.The results of the studies in paddy field and the green house showed that the fecundity and survival rate of the pest were markedly affected by the resistance of the rice varieties. Because the IPC value of rice varieties was a comprehensive reflection of the influence of the varieties on the insect pest population, the index of population control (IPC) could be an important parameter in identifying varietal resistance.