The Impact Of Sublethal Effect And Related Genes Of Chlorfenapyr And Chlorpyrifos On Blattisocius Dentriticus(Berlese)

Blattisocius dentriticus?Berlese?,belongs to Arachnida,Acari,Parasitiformes,Gamasida,Ascidae,Blattisocius,is one of the important biological control agents for Panonychus citri,Brevipalpus obovatus and Tyrophagus putrescentiae.In order to guide the scientific application of pesticides,protect natural enemies,improve the efficacy of pest control and balance the conflict between chemical control and biological control,this thesis was aim to estimate the impacts of sublethal effect on B.dentriticus against chlorfenapyr and chlorpyrifos,including the variations on development,reproduction and feeding features,in addition with the activities of the major detoxification enzymes and their expression levels of corresponding genes.The results are as follows:1.The impacts of sublethal concentrations of chlorfenapyr and chlorpyrifos on development and reproduction of B.dentriticus.The residual film method was adopted to investigate the virulence of chlorfenapyr and chlorpyrifos against the female adults of B.dentriticus.According to the results,virulence regression equation of chlorfenapyr against B.dentriticus was y=-7.570+4.095 x.The indicators of LC₅₀,LC₃₀,LC₂₀ and LC₁₀ were 70.59,52.56,43.97 and34.34 mg/L,respectively.For chlorpyrifos,the virulence regression equation was y=-5.592+2.936 x.The indicators of LC₅₀,LC₃₀,LC₂₀ and LC₁₀0 against chlorpyrifos were 80.21,54.15,45.01 and 34.84 mg/L,respectively.To explore the impacts of chlorpyrifos and chlorfenapyr on developmental and reproductive features,the felame adults of B.dentriticus were challenged with the doses of LC₃₀ and LC₁₀ of these two pesticides.The results indicated that,the longevity,oviposition period and fecundity of the female adult were reduced after treated with chlorpyrifos and chlorfenapyr,which displayed dosage effect.And the hatchability was constant,total ovisiposition number of each treatment was slightly reduced by the two pesticides,except one which was treated by LC₃₀ concentration of chlorpyrifos,made their total ovisiposition number significantly reduced.However,for F₁,chlorpyrifos and chlorfenapyr had no significant effects on the indicators of longevity and hatching rate.But,the developmental duriation was prolonged to some extent.2.The impacts of sublethal concentrations of chlorfenapyr and chlorpyrifos on predation function of B.dentriticus.The female adults of B.dentriticus were treated with chlorfenapyr and chlorpyrifos with the doses of LC₃₀,LC₂₀ and LC₁₀0 to estimate the impacts on the predatory functional responses of F₀ and F₁.The data show that the predatory capacities of F₀ were decreased with the doses increased after treated with chlorfenapyr and chlorpyrifos.The inhibitions were highly significant at the dose of LC₃₀.Besides,the daily predatory capacity,instantaneous attack rate and predation ability decreased,as well as the processing time of F₀ increased.However,the total predatory capacity against Panonychus citri nymph,daily predatory capacity and instantaneous attack rate of F₁ were not affected by chlorfenapyr and chlorpyrifos(LC₃₀ and LC₁₀).3.The impacts of sublethal concentrations of chlorfenapyr and chlorpyrifos on detoxifying enzymes in B.dentriticus.The activities of CarE,GSTs and MFOs of B.dentriticus were investgated in the reserach.The results show that the two pesticides both can stimulate the activity of GSTs in B.dentriticus,and with the rising of concentration,the action showed stronger.For chlorfenapyr,only LC₅₀ concentration can stimulate the activity of MFOs significantly;while with the rising of chlorpyrifos concentration,the inducible effect of MFOs was stronger.For CarE,only high concentration(LC₅₀)of two pesticides has the induction.4.The impacts of sublethal concentrations of chlorfenapyr and chlorpyrifos on detoxifying metabolism genes expression in B.dentriticus.In total,21 detoxification genes?8 GSTs,8 CYPs and 5 CarEs?were selected to evaluate the expression profiles after challenged with chlorfenapyr and chlorpyrifos(LC₅₀,LC₃₀ and LC₁₀),using beta-actin as their reference gene.The data show that the relative expression of BdGST5 and BdGST8 was up-regulated significantly after treated with chlorfenapyr at different concentrations.Compared with the control,they was up-regulated by 4.53 and 9.47 times at LC₅₀,respectively.At the same time,the relative expression of BdGST2,BdGST3 and BdGST4 was down-regulated at low concentrations,but up-regulated by 1.58,3.83,and 2.66 times at the high concentration,respectively.Furthermore,the higher of the concentration of chlorfenapyr,the more up-regulateion about the relative expression of BdGST1,BdGST6 and BdGST7 in B.dentriticus.BdCYP3,BdCYP4 and BdCYP5 were the same situation as above.BdCYP6was up-regulated by 1.94 times at high concentration.The relative expression of BdCYP7 and BdCYP8 was both up-regulated at LC₅₀.Meanwhile the relative expression of BdCarE1,BdCarE4 and BdCarE5 was both up-regulated in B.dentriticus as the concentrations were higher.But the lower of the concentration of chlorfenapyr,the more up-regulation about the relative expression of BdCarE2 and BdCarE3 in B.dentriticus.Under the stress of sublethal concentrations of chlorpyrifos,the higher of the concentration,the more up-regulation about the relative expression of BdGST1,BdGST5 and BdGST6 in B.dentriticus.Only under high sublethal concentrations,the relative expression of BdGST2,BdGST3,BdGST7 and BdGST8 was significantly up-regulated.But the relative expression of BdGST4 was down-regulated slightly.Simultaneously the relative expression of BdCYP1 and BdCYP5 were down-regulated at different concentrations,and the range of up-regulation was different.The relative expression of BdCYP3,BdCYP7 and BdCYP8 was up-regulated,the up-regulation of BdCYP8 was the highest.Under low contentrations,the relative expression of BdCYP2,BdCYP4 and BdCYP6 weas slightly down-regulated;as the concentrations increased,it's going in the opposite direction.Only under high sublethal concentrations of chlorpyrifos,the relative expression of BdCarE2,BdCarE3 and BdCarE4 was significantly up-regulated.