Studies On Resistance Of Rice Planthoppers To Chemical Insecticides In Guizhou Province

This article described preliminary study on resistance index test about the Sogatella furcifera (Horvath) in 9 aeras (Dushan, Huaxi, Xingyi, Huangping, Tianzhu, Meitan, Zunyi, Sinan and Weining.) and the Nilaparvata lugens (Stal) in 6 aeras (Dushan, Huaxi, Huangping, Tianzhu, Sinan and Weining) to organophosphates, carbamates, Pyrethroi, Imidacloprid and buprofezin. And calculated the resistence index, and monitored the development of resistence. By the resistence's level and the change of it, the management measures were advanced .Main conclusions as follows:1. The resistence of S. furcifera in Dushan and Huaxi to 5 insecticides is little higher and higher in three months.The resistence index of the S. furcifera to Parathion-methy, Carbary, Isoprocarb, high-active Cypermethrin and Imidacloprid is higher and higher in the three monthsby the experiment.2. The resistence level of two planthoppers to the five insecticides is lower. The Sogatella furcifera is sensitive to Parathion-methy, high-active Cypermethrinand Deltamethrin the. The resistence level of the 5. furcifera is lower(5 50 of the white plant hopper to Isoprocarb, Imidacloprid and buprofezin is higher than the Nilaparvata lugens clearly. The difference between LD₅₀ of two rice planthoppers is not obvious. Only the RI of N. lugens is higher than S. furcifera.5. The toxicological effect to S. furcifer of isoprocarb and their mixtures in proportion and test result shows the mixture insectides have the best toxicity affect.