Species Sensitivity Distribution (SSD) profiles of carabid beetle communities exposed to acetamiprid, chlorpyrifos or λ-cyhalothrin

Abstract

Many carabid species are essential for pest management in agricultural areas, but at the same time can be exposed to pesticides. To understand how pesticides may affect ecosystem services provided by carabids, it is crucial to assess the effects of exposure not only for individual species but for whole communities. The objective of our study was thus to assess the distribution of sensitivity in carabid communities inhabiting agricultural landscapes toward three insecticides representing three major groups: neonicotinoid acetamiprid, organophosphate chlorpyrifos, and pyrethroid λ-cyhalothrin. Using a vial test, in which an active ingredient dissolved in acetone is evenly distributed inside a glass vial, we first assessed the median lethal doses (24-h LD₅₀) for each insecticide to 10–20 species collected in agricultural areas, which were further used to establish Species Sensitivity Distribution (SSD) profiles. Each insecticide tested caused a serious threat to beetle communities at the recommended field doses, with the strongest effect caused by chlorpyrifos and the weakest by acetamiprid. The estimated Potentially Affected Fraction (PAF) of species at doses of the insecticides recommended for field use was 100 % for chlorpyrifos, 99.8 % for λ-cyhalothrin, and ca. 66 % for acetamiprid. The Hazardous Doses for 5 % species (HD5) were 0.034, 0.47, and 3.79 % of their recommended field doses, respectively. Our findings prove that carabids are a group of ecosystem service providers at considerable risk from insecticide exposure.