Susceptibility of epigeic earthworm Eisenia fetida to agricultural application of six insecticides.

Ecotoxicological risks of agricultural application of six insecticides to soil organisms were evaluated by acute toxicity tests under laboratory condition following OECD guidelines using the epigeic earthworm Eisenia fetida as the test organism. The organochlorine insecticide endosulfan (LC(50) - 0.002 mg kg(-1)) and the carbamate insecticides aldicarb (LC(50) - 9.42 mg kg(-1)) and carbaryl (LC(50) - 14.81 mg kg(-1)) were found ecologically most dangerous because LC(50) values of these insecticides were lower than the respective recommended agricultural dose (RAD). Although E. fetida was found highly susceptible to the pyrethroid insecticide cypermethrin (LC(50) - 0.054 mg kg(-1)), the value was higher than its RAD. The organophosphate insecticides chlorpyrifos (LC(50) - 28.58 mg kg(-1)), and monocrotophos (LC(50) - 39.75 mg kg(-1)) were found less toxic and ecologically safe because the LC(50) values were much higher than their respective RAD.