Controlling Effect of Different Insecticides to Cnaphalocrocis medinalis Guenee

Different insecticides were sprayed on paddy field to control larvae of Cnaphalocrocis medinalis Guenee when most larvae were in the 2nd to 3rd instar. Field test showed that Xinnongbao (40% chlorpyrifos EC) 80 ml/667m2, 2.5% cyhalothrin EC 30~50 ml/667m2 and Zhongjuanqing (35% acephate-chlorpyrifos WP) 80 g/667m2 obtained good results. Their rates of healthy leaf and larva death were higher among all test plots. Those insecticides should be largely applied on controlling the pest. Field test also showed that triazophos and monosultap could not control the larvae effectively, nor could protect leaves of rice as wish. So, they are not recommended to control the larvae at the age of older than 3rd instar.