Toxicity And Sublethal Effects Of Six Insecticides On Chrysoperla Sinica(Tjeder)

Chrysoperla sinica（Tjeder）is widely distributed in the field,and its predation is large.It has a good control effect on the occurrence of aphids,mites,leafhoppers,scale insects and other pests in the field.Moreover,it is easy to feed in the room and can reproduce in large numbers,which has a broad prospect of application.In this study,the toxicity and sublethal effect of Bifenthrin,Chlorfenapyr,Diafenthiuro,Acetamiprid,Tebufenozide and Thiacloprid on Chrysopa Sinica were determined by drug membrane method,which can provide theoretical basis for the rational use of pesticides and the protection of natural enemies.In this study,the acute toxicity of Bifenthrin and other six insecticides to the larva of Chrysopa Sinica was determined as follows:Chlorfenapyr>Diafenthiuron>Bifenthrin>Thiacloprid>Acetamiprid>Tebufenozide.The LC₅₀ values were 1.02mg/L,7.85mg/L,39.72mg/L,91.81mg/L and 165.43mg/L,respectively.The toxicity of Tebufenozide was not measured in this study,which indicated that the acute toxicity of Tebufenozide was very low.The risk of six insecticides to Chrysomyia Sinica was as follows:Chlorfenapyr>Diafenthiuron>Thiacloprid>Bifenthrin>Acetamiprid>Tebufenozide.Among them,Chlorfenapyr and Diafenthiuro were very high risk,Thiacloprid and Bifenthrin were medium risk,Acetamiprid and Tebufenozide were low risk.In terms of sublethal effect,the sublethal concentration LC₂₅ of Bifenthrin,Chlorfenapyr,Diafenthiuron,Acetamiprid,Tebufenozide and Thiacloprid had certain effect on larval duration,pupation rate,pupal stage and eclosion rate and had different inhibitory effects on larval development of Chrysopa Sinica.Among them,the development time of larvae treated with Chlorfenapyr was prolonged by 1.37 days,Significant difference compared with the control,but it had little effect on metamorphosis,with the inhibition rate of 3.41%;the development time of larvae treated with Acetamiprid had no change,with the inhibition rate of 33.56%,Significant difference compared with the control.The effect of the two kinds of drugs is obviously in contrast,which may be related to the toxic mechanism.The effect of Tebufenozide on the risk of C.Sinica is low,and the sublethal concentration of Tebufenozide has little effect on C.Sinica.