The English grain aphid, Sitobion avenae (Fabricius) (Hemiptera: Aphididae), is one of the most serious pests of cereals as the transmitter of viral diseases, mainly in wheat, Triticum aestivum. This agricultural pest is controlled with chemical insecticides, which is environmental pollutants and toxic for human. This study evaluated the potential of alternative environmentally friendly compounds to control this insect pest. The activities of digestive, antioxidants, and intermediary metabolism enzymes of S. avenae reared on wheat plants treated with biofertilizers (Biofarm and Probio96) and micronutrients (Librel Zinc and α-Iron) in the greenhouse were evaluated. The results reveal that α-amylase, total protease, trypsin, chymotrypsin, amino- and carboxypeptidases, alanineand aspartate- aminotransferases, and acid phosphatase enzymes had lower activities in S. avenae reared on Biofarm treated plants compared to control. On the other hand, aphids reared on treated plants with Biofarm had the highest activities of antioxidant enzymes superoxide dismutase, catalase, peroxidase, and ascorbate oxidase, γ- glutamyl transferase, as well as lactate dehydrogenase. Moreover, the oxidized/reduced thiols ratio and malondialdehyde indicated higher activity in the aphids reared on Biofarm-treated plants than control. These results suggest that the bio-fertilizer Biofarm may compromise the physiology of S. avenae as a potential alternative toll in the integrated pest management of this aphid
