Effects Of Five Pesticides On Toxicity,and Enzyme System In Phauda Flammans Walker(Lepidoptera:Zygaenidae)

Effects of beta-cypermethrin,abamectin,chlorpyrifos,thiamethoxam and bisultap on toxicity against 1st-6th instar larvae in Phauda flammans Walker(Lepidoptera:Zygaenidae)were tested using the leaf-dipping method.Meanwhile,effects of these pesticides on detoxifying enzyme,protective enzyme and acetylcholinesterase in P.flammans larvae were also measured.Results showed that the sub-lethal concentrations of beta-cypermethrin,abamectin,chlorpyrifos,thiamethoxam and bisultap against P.flammans larvae was related to the instar and pesticide.Control efficacy of beta-cypermethrin was the best among of these pesticides,in which sub-lethal concentrations of 1st instar larvae in P.flammans reached 2.038 mg/L at 8 h after treatment,and reached 6.416?48.764 mg/L for 2nd-6th instar larvae at 24 h after treatment.Control efficacy of abamectin was less than beta-cypermethrin,which sub-lethal concentrations of 1st instar larvae in P.flammans reached 241.953 mg/L at 8 h after treatment,and reached 19.285?266.207 mg/L for 2nd-6th instar larvae at 24 h after treatment.Control efficacy of chlorpyrifos,thiamethoxam and bisultap was less than the first two pesticides.Changes of enzymes in P.flammans larvae were related to the kinds of enzyme and its sensitivity to different pesticide after treatment.Compared with control,effect of beta-cypermethrin on CarE was the most obvious than other four pesticides.Activity of GST was inhibited by abamectin,while the trend was in the opposite direction for other four pesticides.Activity of SOD was promoted by beta-cypermethrin and chlorpyrifos,and inhibited by abamectin and bisultap.Activity of CAT was promoted by beta-cypermethrin,chlorpyrifos and bisultap,inhibited the influence of promotion by thiamethoxam.Activity of AChE was promoted by beta-cypermethrin,and inhibited by other four pesticides.Results suggested that P.flammans larvae could be effectively controlled by beta-cypermethrin 10 mg/L and abamectin 25 mg/L with alternate spray,which could prevent the resistance to pesticides in this pest.