The efficiency and biochemical effects of certain insecticides belonging to different groups namely: emamectin benzoate (Avermactin^R), flubendiamide (Diamide), lufenuron (IGR) as pyridalyl (phenyl-pyridaloxy) were tested against 4^th larval instar of Spodoptera littoralis (Boisd.)laboratory and field strains using dipping technique. Biochemical effects of the tested insecticides on acetylcholinesterase (AChE) and glutathione-S-transferases (GST) were determined in the treated larvae. The efficacy of the tested insecticides is arranged as follows to LC₅₀ values.  The results showed that that flubendiamide was the superior toxicant insecticides (LC₅₀ values were 0.863 ppm and 2.73 ppm for lab and field strains respectively) followed by emamectin benzoate (LC₅₀ values were 1.8 ppm and 10.13 ppm for lab and field strains respectively) then pyridalyl (LC₅₀ values were 4.17 ppm and 38.2 ppm for lab and field strains respectively) and lufenuron (LC₅₀ values were 5.4 ppm and 76.92 ppm for lab and field strains respectively). The data revealed that the treatment with tested insecticides demonstrated inhibition in AChE and GST activity. Based on the results of the present study, it was confirmed the potency of these insecticides against S. littoralis therefor, should be use their use in control programmes.