Field and laboratory experiments were carried out to evaluate the two insect growth (IGRs), lufenuron and teflubenzuron, antifeedant compoundindoxacab, miniral oil(Kz oil), compound Protecto, Bacillus thuringinsis(Bt)and Dursban, chlorpyrifos against the larvae of cotton leafworm, Spodoptera littoralis(Boisd.).Field experiment conducted during 2013 and 2014 seasons at KafrSakrregion, SharkyiaGovernorate, Egypt. Results revealed that,chlorpyrifos recordedhighest initial reduction (89.38 and 88.39%), residual mean (88.52 and 87.72%) and annual mean (87.74 and 87.37%) onSpodoptera littoralis during the two successive seasons, respectively.
In regarding to the biochemical activites of treated larvae in laboratory the all tested compoundsdisruptedthe testedactivities. The highest effect on the total soluble protein as specific activity( SA) of 40.57 mg/g.bwt recorded for 4th instar larvae treated with LC50 concentration of chlorpyrifose and sampled after 3 days of treatment, while the highest reduction in relative activity (RA%) of - 54.15% recorded for larvae treated with LC50 concentration of Betavant and sampled after 3 days also. The tested compounds at selected concentrations of LC25 and LC50 also disrupted GOT and GPT activities of treated larvae where the highest GOT as SA (2574.33±30.4 u * 103g.sbwt) recorded for larvae treated with LC25 concentration and sampled after 3 days of treatment, while the highest relative activity RA% -43.36%was exhibited in case of after 7 days of treat.the larvae treated with chlorpyrifose and sampled . The highest effect on GPT as SA (711.33±5.2 u *103 g. bwt) was recorded for larvae treated with Komatch at concentration of LC25and sampled at 3rd days of treatment, while the highest relative activity% -64.05 recorded for larvae treated with LC50 concentration of Betavant and sampled at 3rd day of treatment also. Inregarding to the effect of tested compounds on carbohydrate hydrolyzing enzymes;invertase, trehalase and amylase determined as µg glucose/min g.bwt/days. The highest values were 405.679±9.03, 222.33±7.26 and 123±3.31 recorded for larvae treated with LC25of Kz oil, LC50 of Kz oil and LC25 of Betavant sampled at 3rd day of treatment for invertase, trehalase and amylase enzymes,respectively.On the other hand, the highest relative activity RA% of -0.53, -0.44 and -0.61 were recorded for larvae treated with LC50 of Nomult (at 3days of treatment), LC25 of Nomult (at 3rd day of treatment) and LC50 of Kz oil (at 7 days of treatment) that for invertase, trehalase and amylase, respectively.