Species Sensitivity Distribution (SSD) profiles towards λ-cyhalothrin for key ecosystem service provider (ESP)...

Although our understanding of the dramatic worldwide loss of biodiversity in recent decades is far from adequate, one of the main factors in areas dominated by agriculture is undoubtedly the widespread use of synthetic pesticides. Unfortunately, the ecological risk assessment (EcoRA) for pesticides is based on a few single-species bioassays which do not allow for the evaluation of risks to whole communities. Here we present the results of an experimental assessment of the risk to the ecosystem service provider (ESP) communities - pest control agents - from exposure to the commonly used pyrethroid insecticide, λ-cyhalothrin. The study was performed in five European countries (Germany, Poland, Portugal, Spain, United Kingdom) representing different pedoclimatic zones. Representatives of the most common species of the ESP communities in each country were exposed in a standardized insecticide-coated glass vials bioassay to five doses of λ-cyhalothrin: 0.8 %, 4 %, 20 %, 100 %, and 200 % of the recommended field dose (RFD) plus an untreated control. Based on the calculated LD₅₀s, species sensitivity distributions (SSDs) were estimated for each country and on combined data. In all five countries, the estimated hazardous concentration for 5 % of the species (HD5) was between 0.23 % and 1.67 % RFD, with HD5 = 0.44 % RFD based on combined data. At the RFD = 7.5 g a.i./ha (active ingredient per hectare), the predicted affected fraction of the ESP communities was between 96.4 % and 99.9 % of the species (98.5 % for combined data). The results indicate an extremely high risk to ESP communities across Europe associated with the use of λ-cyhalothrin at the recommended doses when these species are exposed to insecticide treatment. We recommend that EcoRA should include multi-species approaches, such as SSD, to better protect entire ESP communities from the negative impacts of pesticides.