The English grain aphid, Sitobion avenae (Fabricius) (Hemi.: Aphididae), is one of the most serious pests of cereals, especially wheat, Triticum aestivum L. in recent years and it is an important factor in transmission of Barley yellow dwarf virus (BYDV). In this study, the activity of digestive enzymes and intermediary metabolisms of S. avenae reared on treated wheat by bio- fertilizers (Biofarm and Probio96) and micronutrients (α-Iron and Librel Zinc) versus control were investigated under greenhouse condition [at 25 ± 5 oC, 60 ± 5 % RH and 16: 8 (L: D) h]. The results illustrated that the bio- fertilizers and micronutrients had a significant effect on the digestive enzymes and intermediary metabolisms of S. avenae reared on different treatments. The highest and lowest activity of general protease, trypsin and chymotrypsin were in S. avenae reared on control (0.772, 9.921 and 9.815 U/mg protein) and Biofarm- treated plant (0.468, 5.014 and 1.511 U/mg protein), respectively. Moreover, aphids reared on control (6.440 and 12.084 U/mg protein) and Biofarm- treated plants (1.216 and 3.331 U/mg protein) demonstrated the highest and the lowest activity of amino- and carboxy- peptidase enzymes, respectively. The highest activity of alanine- (ALT) and aspartate- aminotransferase (AST) enzymes of S. avenae were observed in control (2.003 and 0.575 U/mg protein, respectively) and the lowest amount of them were obtained in Biofarm treated (0.943 and 0.385 U/mg protein, respectively). On the other hand, the highest γ- glutamyl transferase (γ-GT) enzyme activity of S. avenae was observed in Biofarm fertilizer (3.320 U/mg protein) and the lowest one was recorded in control (0.497 U/mg protein), respectively. According to the results, Biofarm bio- fertilizer could disrupt the physiological activities of English grain aphid via increasing the amount of secondary metabolites especially phenolic compounds, as result of this treatment could be introduced as a suitable factor in integrated pest management (IPM).