Sublethal Effect Of Metaflumizone On Spodoptera Litura

Spodoptera litura is a polyphagous and explosive worldwide pest.At present,the main method to control Spodoptera litura is pesticides..Metaflumizone is a new sodium channel blocker,it has excellent insecticidal activity against Lepidoptera pests.Sublethal effects of metaflumizone on Spodoptera litura were studied in this paper.The following conclusions were drawn:1.The toxicity of metaflumizone to the 3rd instar larvae of Spodoptera litura was determined by mixed toxicity method of artificial diet.The 3rd instar larvae of Spodoptera litura were treated with sublethal doses LC₁₀ and LC₂₅ for 48 hours,and the population parameters were analyzed by the method of Two-sex life table.The results showed that the developmental duration of immature larvae in F₀ generations of Spodoptera litura was shortened to a certain extent after treatmentedby LC₁₀0 and LC₂₅ doses of metaflumizone,but the F₁ was longer.On F₀ and F₁ generations,the larval survival rate,pupation rate,emergence rate and hatching rate of progeny eggs decreased with the increase of the concentration,and the pupa weight decreased.Meanwhile,the single female oviposition of F₀ and F₁ generations decreased significantly compared with the control and in a dose.The number of eggs laid by LC₁₀,LC₂₅ and F₀ generation was1053.43,937.37 and 1656.33,respectively,and F₁ generation was 942.54,892.76 and1421.67.The R₀,r_m,?and GRR of LC₁₀ and LC₂₅ treatment groups were significantly less than the control,the average generation time?T?was significantly longer.These results showed that sublethal metaflumizone significantly affected the growth,development and reproduction and inhibited the population growth of Spodoptera litura.2.The effects of the lethal concentration of metaflumizone on the 6th instar larvae of Spodoptera litura were studied by using the mixed drug method of LC₁₀ and LC₂₅ to treat the 6th instar larvae of Spodoptera litura.The results showed that the relative growth,food utilization and food conversion rate of 6th instar larvae of Spodoptera litura were significantly lower than those of the control,and the food utilization rate and food conversion rate decreased respectively.4.5%,11.7%,and 39.3%,49.5%,while the difference between relative consumption and approximate consumption rate is not significant.3.Three kinds of enzyme inhibitors of triphenyl phosphate?TPP?,diethyl maleate?DEM?and piperonyl butoxide?PBO?were determined by the mixed method of feed to the genus Spodoptera litura.The results of virulence synergy to 6th instar larvae showed that the synergistic ratios of the three enzyme inhibitors of PBO,TPP and DEM were 1.75,1.32and 1.25.4.The 6th instar larvae of Spodoptera litura mites were treated with the LC₁₀ and LC₂₅ concentrations of carboxylesterase?CarE?,glutathione-S transferase?GSTs?and multifunctional oxidase?MFOs?three detoxification enzyme activities for 12h,24h,36h and 48h..The results showed that the difference of CarE activity and control in the treatment group was not significant at each time.The activity of GSTs was significantly higher than that of the control at 36 h and 48 h,and the activity of MFOs in the treatment group was higher than that in the control.