Toxicity of endosulfan and carbofuran to earthworms

摘要

Earthworms, the major benefactors to soil, are affected by various agricultural practices, pesticide application in particular. These pesticides may affect the earthworms through soil contamination. Reduction of earthworm population due to intense pesticide contamination in soils has been well documented (Edwards, 1984; Lee, 1985), but little work has been done on this aspect in Tamil Nadu. Hence, this study was undertaken to test the toxicity of two commonly used insecticides viz., endosulfan 35 EC and carbofuran 3G. Endosulfan is normally recommended during the early stages of many crops against sucking and chewing insects (Vasantharaj David and Kumaraswamy, 1988) and hence it has a greater potential to reach the soil for lack of adequate leaf cover area. Carbofuran is a widely used soil insecticide which has a longer persistence period and hence these two insecticides were selected for the study.