In this study, we used two different types of bioassay, a contact filter paper toxicity bioassay and a soil toxicity bioassay, to compare the acute toxicity of twenty-four insecticides belonging to six chemical categories on earthworm species, Eisenia fetida. It was concluded that irrespective of bioassay systems, earthworms were more susceptible to neonicotinoids than to other modern synthetic insecticides.
Wang,Y., et al.,Comparative acute toxicity of twenty-four insecticides to earthworm, Eisenia fetida. Ecotoxicol. Environ.Saf. (2012), doi:10.1016/j.ecoenv.2011.12.016 (attached)