he present study aimed to evaluate the effect of Emamectin benzoate and Bacillus thuringiensis as bioinsecticides as well as the organophosphorus compound, chlorpyrifos on the 2nd and 4th instar larvae of S. littoralis under laboratory conditions. The results showed a decrease in both larval and pupal duration after larvae treatment. Results also showed a decrease in the pupation and the adult emergence percentage compared to the control. Moreover, adult longevity of male and female moths was affected. In addition, mean number of eggs laid and hatched /female as a result of treatment was reduced. Results showed also that the treatment with tested compounds presented and biochemical components impact on the activity of certain enzymes, e.g. total carbohydrates, total proteins, digestive enzymes, Acetylcholinesterase (AChE) and Glutathione S-transferase (GST).