posted on 2022-01-23, 17:59authored byClaudia de Lima e Silva, Winona Brice de Rooij, Rudo Verweij, Cornelis A. M. van Gestel
In this paper we compared the toxicity of the neonicotinoids imidacloprid, thiacloprid, thiamethoxam, acetamiprid and clothianidin to the survival and reproduction of two species of soil invertebrates: Folsomia candida and Eisenia andrei. Tests were performed using LUFA 2.2 natural soil, following standard protocols aimed at answering two questions: (i) Is there a difference in the toxicity between pure compound and its formulation? (ii) Is there a difference in the sensitivity of the species exposed to the same compound? Formulations and pure compounds presented similar toxicity to both endpoints tested for E. andrei. For F. candida, acetamiprid and imidacloprid presented different toxicity, with the first being four times more toxic to survival (LC50 0.12 mg a.s./kg dry soil and the latter, four times more toxic to the reproduction of the springtail (EC50 0.25 mg a.s./kg dry soil) than their commercial formulation. The most toxic compound to E. andrei was acetamiprid (LC50 0.80 and EC50 0.35-0.40 mg a.s./kg), and for F. candida clothianidin (LC50 0.07 and EC50 0.05 mg a.s./kg). Estimated risk ratios indicated that only one application per year of clothianidin in the formulation Poncho® may pose a threat to the populations of springtails and earthworms.