esterase activity in homogenates of spodoptera frugiperda (j.e. smith) exposed to low-lethal doses of chlorantraniliprole and emamectin benzoate

Background: chlorantraniliprole and emamectin benzoate have been widely used to control pests including faw. for effective pest control, the sublethal effects of these insecticides should be considered.methods: the toxicity of chlorantraniliprole and emamectin benzoate to third-instar faw larvae has been determined using topical application. alpha esterase (est-α) and beta esterase (est-β) activity were also assessed after 1, 6, 12, 24, and 48 h of exposure of larvae to low doses of these insecticides.results: the susceptibility of faw larvae to chlorantraniliprole and emamectin benzoate increased after 48 h, and the ld50 was 0.18 and 0.23 μg/larvae, respectively.est-α and -β activity changed significantly in faw larvae over time after exposure to insecticides. after only 1 h, est-α, and -β activity after exposure of larvae to insecticides at ld10 showed no significant difference compared to control. however, under ld30 treatments, the activity of est-α and -β decreased significantly. significant reduction of est-α and -β activity was observed in larvae after 48 h exposure to chlorantraniliprole at ld30 (0.5 and 0.15 nmol/min/mg protein, respectively) followed by emamectin benzoate (1.19 and 0.29 nmol/min/mg protein, respectively) compared with control activity.conclusion: sublethal doses of chlorantraniliprole and emamectin benzoate affected activities of est-α and -β of faw.