Efficacy Evaluation of Five Kinds of Botanical Insecticides to Control Hlyphantria cunea(Drury)in the Field
[Objective]To evaluate the field efficacy of five botanical insecticides to control Hlyphantria cunea and determine the optimum dosage.[Method]The control efficacy test of spray treatment on the third instar larvae of Hlyphantria cunea before its outbreak was tested in the field.[Result]The best control effect of nocotine·matrine1.2%EC at 6,8,12 mg/L was 87.83%-92.61%on the 3rd day after treatment,and which reached the peak on the 14th day,ranging from 95.85%-97.99%,1.5%matrine soluble concentrate and 0.5%pest chrysanthemum ·matrine soluble concentrate reached the peak on the 14th day after treatment,which were 84.62%-95.13%and 89.14%-91.93%,respec-tively.[Conclusion]The recommended active ingredient content of nocotine·matrine 1.2%EC is 6-12 mg/L,which has the best effect on the control of the 3rd instar larvae before its outbreak,and can be widely used.1.5%matrine soluble concentrate and 0.5%pest chrysanthemum ·matrine soluble concentrate can also be used alternately during the control,which has no adverse effect on the growth of poplar,the species and number of beneficial natural enemies.