Study On The Biological Activity And Functional Mechanism Of 20-Hydroxyecdysone And Cyasterone On Hayrmonia Axyridis (Pallas)(Coleoptera,Coccinellidae)

In order to study the influence of 20-Hydroxyecdysone?20E?and cyasterone on Harmonia axyridis?Pallas?,totally five different concentrations of 20E and cytasterone,which was 0.1g/L,0.5mg/L,1 mg/L,5 mg/L and 10 mg/L,was chosen to treat the 4^th instar larvae and sdult of H axyridis?Pallas?,to find out the changes on larval survival rate,preying amount of 4^th instar larvae and emergence rate of pupa,and egg laying amount,survival rate and preying amount of the adult,the activity of three kinds of protective enzyme,such as superoxide dismutase?SOD?,catalase?CAT?and peroxidase?POD?and three kinds of detoxification enzyme,such as acetyl cholinesterase?AChE?,mixed function oxidase?MFO?and esterase?EST?of the larval and adult,and the activity of two kinds of enzyme related to the formation of larval epidermal in their bodies,which were phenol oxidase?PO?and chitinase?CHIT?.The results shown that after treated by 0.1 mg/L 20E or cyasterone,the larval survival rate,preying amount,and the activities of protective enzyme,detoxification enzyme,PO and CHIT activities of those treated 4^th instar larvae of H.axyridis?Pallas?were not significantly influenced.So it could be considered that this concentration was safe to the 4^th instar larvae of H.axyridis?Pallas?.Treated by 0.5mg/L 20E or cyasterone,the survival rate,predating quantity,emergence rate,the activity of protective enzyme,detoxification enzyme,PO and CHIT of those larvae were slightly influenced,but the impact strength was in the patience range of those treated larvae,so this concentration was considered to be relatively safe to those larvae.When concentration of cyasterone is 1mg/L,48h after treatment,activity of protection enzyme of H.axyridis?Pallas?could still restore to normal level.Using 1mg/L?5mg/L or 10mg/L 20E and 5mg/L or 10mg/L cyasterone to treated the 4^th instar larvae of H.axyridis?Pallas?,the larvae survival rate,predating quantity emergence rate,the activities of protective enzymes,detoxification enzymes,PO and CHIT showed serious adverse effects.So that the 0.5mg/L or lower concentrations of 20E and 1mg/L or lower concentrations of cyasterone were considered to be safe to the 4^th instar larvae of H.axyridis?Pallas?.Five concentration,such as 0.1 mg/L,0.5mg/L,1mg/L,5 mg/L and 10 mg/L of 20E or cyasterone was used to treat adult of H.axyridis?Pallas?,the fecundity,survival rate,predating quantity of those treated adults was not significantly difference with that of control group,and activities of protective enzymes and detoxifying enzymes at 48h after treating were restored to the level that was not significantly difference with that of the control group.So 10mg/L or lower concentrations of 20E or cyasterone was considered to be safe to the adult of H.axyridis?Pallas?.