Cypermethrin (25 e.c.), deltamethrin (2.8 e.c.) and fenvalerate (20 e.c.) were evaluated for their residual toxicity against E. machaeralis (Walk.) under laboratory conditions. Based on LT 50 values e.c. formulations of cypermethrin showed significantly higher residual toxicity to teak skeletonizer, E. machaeralis (Walk.) than that of deltamethrin and fenvalerate. The LT 50 values of these insecticides at 0.075, 0.075 and 0.06 per cent spray concentrations were found in descending order, 17.20 days (cypermethrin), 13.04 days (fenvalerate) and 11.89 days (deltamethrin).
Borse et al. (Tue,) studied this question.