Residue behavior of cyantraniliprole and its ecological effects on Procambarus clarkii associated with the rice-crayfish integrated system

BACKGROUNDCyantraniliprole, a second-generation diamide insecticide, was recently introduced in China, where the rice-crayfish integrated system (RCIS) is practiced to control rice pest infestations. The aim of this study was to investigate the residue behavior of cyantraniliprole in RCIS and its potential ecological effects on nontarget Procambarus clarkii in order to recommend safe pesticide application strategies. RESULTSCyantraniliprole dissipated in rice plants according to first-order kinetics, with an average half-life of 5.25 days and a dissipation rate of >95% over 28 days. The terminal cyantraniliprole residue levels in rice straw, paddy hull and brown rice were all within 0.2 mg kg(-1), which is the China-recommended maximum residue limit. The tissues of P. clarkii accumulated and distributed cyantraniliprole in the descending order gill > hepatopancreas > intestine > muscles. Procambarus clarkii exposed to cyantraniliprole exhibited a moderate decrease in weight gain, specific growth rate and condition factor compared to the control group. Exposure of P. clarkii to cyantraniliprole caused histopathological alterations to the hepatopancreas, but the alterations were not statistically significant in the 60 g ai ha(-1) cyantraniliprole group when compared with the control group. CONCLUSIONWe suggest that 10% cyantraniliprole oil dispersion be sprayed twice at an interval of 14 days and dosage of 60 g ai ha(-1) during the growth stage of rice in RCIS. (c) 2023 Society of Chemical Industry.