Radiation technique proved its excellence as a clean pest control tool. Therefore, the present study was directed to explore the biochemical variation in Spilostethus pandurus (Scop.) (1^st and 5^th nymph instar and 2-day-old male adults) irradiated with different gamma radiation doses (50, 100, 150 and 200 Gy). The testis lactate dehydrogenase and acid phosphatase activities were also estimated in the adult males. The results exhibited a significant decrease in the metabolic products (protein, lipids, and carbohydrates), and the antioxidants response (glutathione–S-Transferase and glutathione reduced) when compared to control. Contrarily, lipid peroxidation content was significantly elevated when compared to the control. Furthermore, the arrangement of the studied ages according to the content of the tested parameters was 2-day-old male adults > 5^th nymph instar > 1^th nymph instar. The testis lactate dehydrogenase and acid phosphatase activities showed a significant increase in the irradiated males. In conclusion, it was observed that gamma radiation generated damaging effects in the physiological system of the different stages of S. pandurus, so it could be used for S. pandurus control.