The present study was designed to evaluate the comparative toxicity of Chlorpyrifos, Lambda (λ) Cyhalothrin and Neem extract (a bio pesticide) against the adults of D. koenigii. A gradual increase in the mortality was found with the increase of concentration. The calculated LC50 values for Chlorpyrifos, λ-Cyhalothrin and Neem extract were 0.0069%, 0.045% and 0.0787% respectively. The order of efficacy of the three pesticides in respect of toxicity was: Chlorpyrifos > λ. Cyhalothrin > Neem

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... t. Effect on fecundity of adult D. koenigii was investigated and it is observed that complete egg inhibition occurred at concentrations of 0.0062%, 0.0039% and 0.048% for Chlorpyrifo, λ. Cyhalothrin and Neem extract respectively. This showed that the three pesticides are same in the order of efficacy regarding toxicity and fecundity. Neem extract was found more effective to decrease the total protein content as compared with Chlorpyrifos and λ-Cyhalothrin. Inhibitory effects on GOT (Glutamate Oxaloacetate Transaminase) enzyme were calculated based on Spectrophotometeric analysis and found to be 10.2% (λ-Cyhalothrin) and 4.9% (Neem extract) where as Chlorpyrifos caused an increase in GOT activity up to 1.28% against the survivorship. The overall efficacy of the three pesticides against the survivorship was in the order of Chlorpyrifos > λ Cyhalothrin > Neem extract. This report covers effectiveness of the given pesticides in respect of various biochemical parameters GOT, Protein content, toxicity, fecundity and survivorship against the adults of D.Koenigii.