Avoidance behaviour and survival of two annelid oligochaetes exposed to two fungicides

Summary

The use of pesticides in crop fields may have negative effects on soil biodiversity. Earthworms and enchytraeids are annelid oligochaetes involved in the evolution of soil organic matter and structure at different complementary scales. This study focused on the impact of two pesticides, an organic fungicide widely used to protect cereal crops in conventional agriculture and copper, a fungicide widely used in organic agriculture on fruit trees, vine or solanaceae to prevent spore germination. We assessed impacts of these fungicides using acute toxicity tests and avoidance behaviour tests on an earthworm and an enchytraeid species, separately, under controlled conditions of temperature and moisture. A natural soil from a fallow was used for the experiments. The results in terms of mortality and ability to detect and avoid different range of fungicide concentrations were discussed comparing species. These results support the need to test impacts of pesticides on enchytraeids, in addition to earthworms, in order to understand ecotoxicological effects of pesticides under field conditions.