The Evaluation of Efficacies of Several Different Insecticides against Cnaphalocrocis medinalis

In order to effectively control Cnaphalocrocis medinalis,we chose 20% chlorine benzamide(Kangkuan) SC,10% fipronil bisamide.avermectin(Daoteng) SC,Bt WP and avermectin benzoate WG to control Cnaphalocrocis medinalis in field trials.The results showed that 7 days after application,the effects of Kangkuan at 10 mL/667m 2 a nd Daoteng at 30 mL/667m 2 were 88.6% and 79.7%,respectively.After 14 days of application, the effects of the Kangkuan and Daoteng were 90.9% and 86.2%,respectively.The insecticidal effects of,Daoteng at 10 mL/667m 2,Bt at 200 g/667m 2 and avermecin benzoated WG at 100 g/667m 2 were 89.0% to 100%,53.2% to 88.3%,84.4% to 97.7%,respectively,at 7 to 14 days after application.The control efficiency of those 4 insecticides were higher than 80%.In addition,the efficacy of 1.8% avermectin EC at 50 mL/667m 2 increased to 81.2% from 76.7% 14 d after application.