Acute toxicity of endosulfan and malathion on Chironomus ramosus (Insecta : Diptera : Chironomidae) from north Cachar hills, Assam, India.

ABSTRACT

Acute toxicity tests for the pesticides endosulfan and malathion on the larvae of Chironomus ramosus were conducted. Median Lethal Concentration (LC50 ) values of endosulfan were 0.55 x 10-2, 0.16 x 10-2, 0.089 x 10-2 and 0.036 x 10-2 ppb respectively, while those for malathion were 0.139 x 10-2, 0.054 x 10-2, 0.019 x 10-2 and 0.0032 x 10-2 ppb respectively, at 24 , 48, 72 and 96 hr. Thus Chironomus ramosus larvae were more sensitive to malathion at all hours of toxicity tests than endosulfan.