Are biopesticides safe for the environment? Effects of pyrethrum extract on the non-target species Daphnia magna

Biopesticides are natural compounds considered more safe and sustainable for the environment. However, it is also important to evaluate the potential risk in non-target organisms. Pyrethrum extract (PE) is a biopesticide, widely used for agriculture, veterinary, and aquaculture. This work aimed to evaluate acute (0.6 - 40.0 mu g/L; 96 h; E(L)C50 toxicity) and sub-chronic (0.7 - 1.1 mu g/L; 10 d; life-history parameters) effects of PE on Daphnia magna. Moreover, a biomarkers approach using antioxidant and biotransformation capacity, lipid peroxidation (LPO), neurotoxicity, and energy reserves content were evaluated. Acute effects (mortality, changes in swimming behavior, oxidative stress, lipid peroxidation, neurotoxicity) were recorded with the increase in PE concentra-tion. Sub-chronic assay showed an increase in energy reserves content, antioxidant parameters, and LPO demonstrating that PE unbalances oxidative metabolism. This study can conclude that PE potentiates toxic ef-fects in D. magna and demonstrates the vulnerability of a non-target organism to PE that is considered envi-ronmentally safe.

Automated summary

Biopesticides, such as pyrethrum extract (PE), are considered safer and more sustainable for the environment. However, this study found that PE can have acute and sub-chronic toxic effects on Daphnia magna, a non-target organism. The research demonstrated increased oxidative stress and lipid peroxidation in D. magna exposed to PE, indicating an imbalance in their oxidative metabolism.