Evaluation of the toxic effects of fluindapyr, a novel SDHI fungicide, to the earthworms Eisenia fetida

The emergence of resistance to existing succinate dehydrogenase inhibitor fungicides (SDHIs) calls for the urgent innovation of novel formulations, but also results in an increase information gap on the ecological risks of novel SDHIs especially to non-target organisms. Herein, the environmental behavior and toxicological effects of a novel SDHI, fluindapyr (FIP), were evaluated using earthworm as model non-target organism. Results showed that FIP had a relatively shorter half-live (about 28 days) in artificial soil compared with traditional SDHIs. Besides, FIP exhibited a rapid uptake and bioaccumulation trend in earthworms. For the toxicological effects, FIP suppressed earthworm growth (≥ 5 mg/kg) and reproduction (≥ 1 mg/kg) whereas no lethal effects were observed up to the highest tested concentration of 25 mg/mg. FIP of high exposure concentrations also induced serious epidermis and intestines damage as well as oxidative stress to earthworms after 28-day exposure. In addition, expression of oxidative damage related genes (CAT, CRT, GST, HSP70, SOD) was further verified after FIP exposure. The earthworm Tier 1 RQ also indicated a potential risk for earthworm reproduction. Data presented here may be useful for the risk assessments of FIP in soil ecosystems and help to set appropriate precautions to ensure protection against novel SDHIs.