Studieswere carried out during 2010-2011 to evaluate toxicity levels of different insecticidesand bio-pesticides against larvae of teak skeletonizer, Eutectonamachaeralis (Walker) which is the most pernicious insect-pest of teak.Endosulfan (35 EC 0.07 %), Chlorpyriphos (20 EC 0.05 %), Lambdacyhalothrin (5EC 0.003 %), Thiamethoxam (25 WG 0.0084 %), Bacillus thuringiensis (Btk)(2 gm/L), Btk (3 gm/L), Beuveria bassiana (2 gm/L), B.bassiana (3 gm/lit) Metarrizium anisopliae (2 gm/L), M.anisopliae (2 gm/L), NSKE (5 %) were tested under laboratory conditionsapart from water spray (control) using Completely Randomized Design with threereplications each on third instar larvae of E. machaeralis. Observationson mortality of the larvae were recorded at 12 hrs 1, 3 and 7 days aftertreatment. Among different treatment tested, lambdacyhalothrin recorded centpercent mortality within 24 hrs after application. Chlorpyriphos and endosulfanwere found to be the next best treatments for their knock down toxicity within24 hrs after application. Considering environment safety control measures for conservingnatural enemies the biopesticides B. thuringiensis (Btk), B. bassiana, M.anisopliae each with 3 gm/L found to be the best treatment causing 50.77 to68.07% percent mortality followed by chemical insecticides. The treatmentsthiamethoxam, B. thuringiensis, B. bassiana, M. anisopliae each with 2gm/L found to be less effective.