Toxicity assessment of 45 pesticides to the epigeic earthworm Eisenia fetida

Abstract

This study was conducted to investigate comparative toxicity of 45 pesticides, including insecticides, acaricides, fungicides, and herbicides, toward the epigeic earthworm Eisenia fetida. Results from a 48-h filter paper contact test indicated that clothianidin, fenpyroximate, and pyridaben were supertoxic to E. fetida with LC50 values ranging from 0.28 (0.24-0.35) to 0.72 (0.60-0.94) μgcm-2, followed by carbaryl, pyridaphenthion, azoxystrobin, cyproconazole, and picoxystrobin with LC50 values ranging from 2.72 (2.22-0.3.19) to 8.48 (7.38-10.21) μgcm-2, while the other pesticides ranged from being relatively nontoxic to very toxic to the worms. When tested in artificial soil for 14d, clothianidin and picoxystrobin showed the highest intrinsic toxicity against E. fetida, and their LC50 values were 6.06 (5.60-6.77) and 7.22 (5.29-8.68) mgkg-1, respectively, followed by fenpyroximate with an LC50 of 75.52 (68.21-86.57) mgkg-1. However, the herbicides fluoroglycofen, paraquat, and pyraflufen-ethyl exhibited the lowest toxicities with LC50 values>1000mgkg-1. In contrast, the other pesticides exhibited relatively low toxicities with LC50 values ranging from 133.5 (124.5-150.5) to 895.2 (754.2-1198.0) mgkg-1. The data presented in this paper provided useful information for evaluating the potential risk of these chemicals to soil invertebrates. © 2012 Elsevier Ltd.