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

Abstract

BACKGROUND: Cyantraniliprole, 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.RESULTS: Cyantraniliprole 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.CONCLUSION: We 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.

Ecological Toxicity of Cyantraniliprole against Procambarus clarkii: Histopathology, Oxidative Stress, and Intestinal Microbiota

“…For example, the 48 h LC 50 of cyantraniliprole for D. magna is 23.9 mg/L, and the chronic toxicity test revealed that the 21 d LC 50 of cyantraniliprole for mobility (13.6 mg/L) could exert lethal and sublethal effects on daphnids . The 96 h LC 50 of cyantraniliprole for juvenile tilapia (Oreochromis mossambicus) was found to be 38.0 mg/L in a previous study, indicating low cyantraniliprole acute toxicity toward tilapia; however, after 28 days of chronic exposure, the tilapia growth rate gradually decreased with increasing cyantraniliprole concentration .…”

“…clarkii per tank (15 L of cyantraniliprole solution or dechlorinated water). Cyantraniliprole concentrations were analyzed using the UPLC-MS/MS detection method established in the previous study …”

“…Cyantraniliprole concentrations were analyzed using the UPLC-MS/MS detection method established in the previous study. 11 Three P. clarkii from each group were randomly selected after 3, 7, and 14 days of exposure and subjected to ice bath anesthesia for 15 min. Abdominal muscle, gills, hepatopancreas, and intestines of P. clarkii were immediately dissected and stored at −80 °C for the analysis of antioxidant enzyme activities and measurement of expression levels of related genes.…”

“…In China, crayfish aquaculture and rice planting are performed together in a pond, and the system is known as the rice−crayfish integrated system (RCIS); their symbiotic relationship improves paddy yield, inhibits weeds, and provides a hospitable environment for crayfish. 11 However, pesticides used in RCIS for food security and pest control can have negative impacts on nontarget organisms; 12 they can be transferred to the aqueous environment through spraying drift and plant uptake and release, which may affect the growth of P. clarkii and subsequently human health. 13 Therefore, it is necessary to comprehensively analyze the ecotoxic effects of pesticides on P. clarkia in RCIS.…”

“…clarkii has served as a model species for the risk assessment of contaminants present in aquatic ecosystems, making it of high ecological and economic value. In China, crayfish aquaculture and rice planting are performed together in a pond, and the system is known as the rice–crayfish integrated system (RCIS); their symbiotic relationship improves paddy yield, inhibits weeds, and provides a hospitable environment for crayfish . However, pesticides used in RCIS for food security and pest control can have negative impacts on nontarget organisms; they can be transferred to the aqueous environment through spraying drift and plant uptake and release, which may affect the growth of P.…”