The Effect of micronutrient fertilizations on some of physiological functions of mature larvae of Hippodamia variegata (Goeze) fed on Myzus persicae (Sulzer

 Myzus persicae (Sulzer) is one of the severe pests of Capsicum annuum L.Hippodamia variegata (Goeze), is an important predator in both the larval and adult stages. In this study, effect of foliar application of micronutrient fertilizers included iron, zinc, copper and manganese were investigated on the activity of antioxidant enzymes, amount of antioxidant non-enzymatic compounds and storage-macromolecules (protein, glycogen and triglyceride) of the third and fourth instar larvae of H. variegata fed on M. persicae. Results showed that the higher amount of protein, glycogen and triglyceride of the third and the fourth instar larvae of H. variegata were obtained on micronutrient fertilizers. The activity of antioxidant enzymes (catalase, superoxide dismutase, peroxidase, ascorbate-peroxidase and glucose-6-phosphate dehydrogenase) and the amount of non-enzymatic compounds (malondialdehyde and thiol) significantly decerased in the third and the fourth instar larvae of H. variegata on the micronutrient treatments compared to control. The increase of superoxide dismutase activity can indicate the occurrence of oxidative stress in the body of the third and the fourth instar larvae of predator H. variegata could be assigned to the accumulation of H2O2 in the body of M. persicae under the influence of the defensive secondary metabolites, which led to increase the activity of catalase and peroxidase. Thus, use of biological control agents along to use of micronutrients fertilizers in the integrated management programs of M. persicae could be effective by increasing of the amount of storage macromolecules and decreasing oxidative conditions, which can affect the vital processes of the predator.