The effect of sub-sterilizing dose of gamma radiation (8Gy) was investigated by film method in the laboratory on the toxicity of malathion to adult pulse beetle Callsobruchus maculatus The LC50 value of malathion against one day-old non-irradiated adults was 4.5 ppm whereas that for irradiated one was 0.5 ppm. Thus results indicated that the combined use of radiation + malathion reduced the requirement of insecticide by 9 times. Though, no significant difference in LC50 of malathion to non-irradiated insects was found within 24–72 h but it was noticed between LC50 and LC90 values in both the cases.
Gamma radiation, Insecticides, Malathion, Callosobruchus maculatus
