Safety Evaluation Of Two Insecticides On Binodoxys Commis

Aphis gossypii,as a worldwide pest,causes serious economic losses to crops by feeding and spreading viruses.As a natural enemy of cotton aphid,Binodoxys commis can effectively control the number of aphids in cotton fields.At present,although many strategies have been developed to control aphids,the most commonly used control method is still chemical control.Sulfoxaflor and flupyradifurone,as newly developed neonicotinoid pesticides,act on insect acetylcholine receptors and have good control effects on target pests,which are widely used in pest control.However,in recent years,the potential effects of sulfoxaflor and flupyrfuranone on non-target arthropod insects have attracted much attention,but there are no reports on the effects of these two insecticides on B.commis.This paper measured sulfoxaflor and flupyrfuranone to A.gossypii and its parasitic enemies B.commis to virulence,made clear the sublethal concentrations of these two agents B.commis development period,longevity,parasitic rate and eclosion rate and the influence of genetic spectrum,in order to reduce the potential risk of chemical pesticide use,which provides the theoretical foundation for the protection of natural enemy insects.The main results were as follows:（1）After 24 h treatment of A.gossypii with two insecticides,The LC₁₀and LC₂₅of sulfoxaflor against cotton aphid were 8.17 mg/L and 15.90 mg/L,and the 95%confidence intervals were 4.64 mg/L-12.00 mg/L and 10.59 mg/L-21.64 mg/L,respectively;The LC₁₀and LC₂₅of flupyradifurone to A.gossypii were 7.70 mg/L and 13.62 mg/L,and the 95%confidence intervals were 5.56 mg/L-9.86 mg/L and 10.71 mg/L-17.2 mg/L,respectively.After 24 h of B.commis treatment with the two insecticides,the LC₁₀and LC₂₅of sulfoxaflor were 50.39 and139.85,and the 95%confidence intervals were 15.56 mg/L-86.34 mg/L and 80.27 mg/L-241.99mg/L,respectively;The LC₁₀and LC₂₅of flupyradifurone were 51.30 and 92.13,and the 95%confidence intervals were 30.26 mg/L-71.91 mg/L and 64.44 mg/L-121.55 mg/L,respectively.（2）The A.gossypii treated with sublethal concentration of sulfoxaflor and flupyradifurone was parasitized by B.commis.The results showed that sulfoxaflor LC₂₅and flupyradifurone LC₁₀,LC₂₅significantly prolonged the developmental period of B.commis by1.23 d,1.43 d and 0.79 d,respectively.However,the sublethal concentration of the two insecticides had no significant effect on the longevity of parental and offspring adults.The sulfoxaflor LC₁₀had no significant effect on the parasitism rate of B.commis,while sulfoxaflor LC₂₅and flupyradifurone LC₁₀,LC₂₅all significantly reduced the parasitization rate of B.commis by 32.33%,44.66%and 52.33%,respectively.At the two tested concentrations,the sublethal dose of sulfoxaflor LC₁₀had a significant effect on the eclosion rate of offspring generation,which was reduced by 22.82%compared with the control group,and the other sublethal concentrations had no significant effect on the eclosion rate of parent and offspring.（3）Adults of B.commis were treated with sulfoxaflor and flupyradifurone at sublethal concentration,the results showed that there was no significant difference in parental development duration between the treatment group and the control group,but the sublethal dose of flupyradifurone could significantly prolong the pupation time of progeny larvae by 0.97 d.After the sublethal dose of the two insecticides,the lifespan of parental adult wasps was significantly reduced by 0.96 d,1.06 d,1.2 d and 0.9 d,respectively.In addition,the lifespan of offspring adult wasps was significantly reduced by flupyradifurone LC₂₅,which was 1.3 d longer than that of the control.Sulfoxaflor and flupyradifurone significantly reduced the parasitism rate of parental parasitoids by 41.67%,52.88%,17.33%and 32.77%,respectively.The parasitism rate of offspring was higher than that of parents,but still lower than that of control group.The sublethal concentration of LC₂₅significantly decreased parental emergence rate by 17.19%and 25.50%,respectively,but had no significant effect on offspring emergence rate.（4）After treatment with sublethal concentrations of fluridanitrile and flupyrfuranone,B.communis was sequenced by transcriptome,gene screening and function,the results showed that the main difference in cell process,metabolic process,an organism metabolism process,biological process adjustment,organisms,enrichment of stimulus-response,development process.KEGG enrichment pathway analysis of differential genes revealed that the differential genes were mainly enriched in carbon metabolism,fatty acid metabolism,purine metabolism,starch and sucrose metabolism,glycerophospholipid metabolism,juvenile hormone binding protein,glutathione metabolism and cytochrome P450 metabolism.Sublethal concentrations of sulfoxaflor and flupyradifurone significantly altered gene expression,and affected growth and development,metabolism and detoxification pathways in B.communis.