Cyantraniliprole Control Underground Pests In The Maize Field By Seed Treatment And Its Ecotoxicity To Earthworms(Eisenia Fetida)

Corn（Zea mays L.）is one of the three major cereal crops in the world,which plays an important role in safeguarding national food security and promoting national economic development.With the change of the farming system,the underground pests（such as black cutworm,grubs,wireworm,mole cricket etc.）occur increasingly serious in corn fields,become a danger to the main problem with corn early growth.With the prohibition of high-toxic and high-residue pesticides,it is urgent to develop efficient and low-residue insecticides to control underground pests.Cyantraniliprole is another effective agent for lepidoptera and coleoptera pests after chlorantraniliprole by Dupont.Studies have shown that cyantraniliprole seed treatment has a better control effect on black cutworm in corn fields.At the same time,with the implementation of the national policy for reducing the use of fertilizers and pesticides,the impact of chemical pesticides on the environment has been attached great importance the impact of chemical pesticides on the environment has been attached great importance.Based on the determination of the toxicity of cyantraniliprole to two kinds of underground pests（wireworms,grubs）in corn fields in this research,the indoor control effect of cyantraniliprole seed treatment on corn underfield pests（wireworms,grubs）was studied by seed coating treatment,and the comprehensive control effect on corn underfield pests was also studied.Finally,in view of the environmental problems that may be caused by its application,earthworm was selected as the test object,and the ecotoxicity of cyantraniliprole to earthworms was evaluated.The main test results are as follows:The LC₅₀values of cyantraniliprole against Pleonomus canaliculatus and 2nd instar larvae of Anomala corpulenta were 23.3712 mg/L（immersion of the insect）,5.9715 mg/L（immersion of the insect）.It has high virulence to both underground pests.The safety test results of cyantraniliprole seed treatment on corn showed that the sand culture test and soil culture test under indoor conditions proved that the cyantraniliprole seed treatment was safe for corn and had a certain promotion effect on the growth of seedlings.The effect of cyantraniliprole seed treatment on the indoor pot inoculation of Pleonomus canaliculatus and grubs showed that cyantraniliprole has a better control effect on the Pleonomus canaliculatus and grubs.15 days after the indoor pot sowing,it is effective for The control effect was 75.82%and 83.66%at the dose of 3 and 4 g ai/kg seed,and the control effect of grub was 79.94%and 83.25%.The two-year comprehensive control effects of cyantraniliprole seed treatment on corn field underground pests at 3 and 4 g ai/kg doses 21 days after corn emergence were 67.12%and 73.97%（2019）,67.69%and 74.7%（2020）.The impact of corn yield in 2019 and2020 shows that cyantraniliprole seed treatment can significantly reduce the yield reduction caused by corn pests,and the yield increase rate is 6.31-14.70%（2019）compared with CK,and the yield increase rate is 8.85-18.14%（2020）compared with CK.The ecotoxicity of cyantraniliprole to earthworms showed that cyantraniliprole concentration of 5 and 10 mg/kg OECD soil has a certain inhibitory effect on the growth and reproduction of earthworms,and can induce MDA and ROS in earthworms.Produce and lead to increased protein carbonylation.It can promote or inhibit the activities of antioxidant enzymes and detoxification enzymes in earthworms.As the concentration increased,the degree of DNA damage of cyantraniliprole to earthworm coelomic cells increased.At the same time,we selected HSP70 and CAT gene for stress resistance,ANN gene for reproduction,and RYR and CAM gene as targets to study the effect of cyantraniliprole on the expression of related functional genes in earthworms.Cyantraniliprole can up-regulate or down-regulate the expression of related genes in earthworms.Finally,we conducted transcriptomics.From the data,we can conclude that cyantraniliprole exposure can affect earthworm amino sugar and nucleotide sugar metabolism,protein and lipid synthesis,steroid hormone biosynthesis and other pathways.At the same time,the RT-PCR confirmed that cyantraniliprole can cause oxidative stress in earthworms,and affect the reproduction,growth and development of earthworms,as well as the metabolism of glucose,lipid and protein pathways.The above results show that cyantraniliprole can be used to control underground pests in corn fields,and according to previous studies,the residual amount of cyantraniliprole in corn fields will not exceed 5 mg/kg,so as long as it is used reasonably,it will not cause damage to the soil environment.