Activity of antioxidant defense system in fenoxycarb treated mango leaf webber Orthaga exvinacea Hampson (Lepidoptera: Pyralidae)

The toxicity of the synthetic insecticide fenoxycarb, an insect growth inhibitor, was assayed against the sixth instar larvae of Orthaga exvinacea. This lepidopteran pest is considered as major annoyance of mango cultivation throughout India which could significantly reduce the crop yield. The lethality of this insecticide with different concentrations against the organism was examined. The effect of this insecticide on the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), peroxidase (POD) and glutathione reductase (GR) was estimated. The results revealed that the insecticide exerted excellent larvicidal activity against the target organism with an LD50 value of 30.339 ppm. The observations revealed that there was a consistent cutback in the activity of all of the antioxidant defense enzymes in response to the sublethal doses of the insecticide. The fenoxycarb treatment also resulted in lipid peroxidation (LPO) in the larvae. With reference to O. exvinacea, this study may provide information about the biological and physiological effects of fenoxycarb on pest species.