Laboratory studies were carried out in an attempt to disclose the effect of a bio-insecticide (Spinosad),  and IGR (consult) and their mixture at different concentrations (19 ppm), (123 ppm)  and (9ppm of spinosad+52 ppm of consult), respectively on one day old of the 5^th nymphal instar of the desert locust, Schistocerca gregaria (Forskal) by feeding technique.  the insect enzymes acid phosphatase and Phenoloxidase activities and total carbohydrates were affected fluctuated between increasing and decreasing after 2, 4 and 6 days of treatment with Spinosad (at LC₅₀ value), consult(at LC₅₀ value) and their mixture(at LC₂₅ values). acid phosphatase activity and phenoloxidase activity were dramatically declined in all treatments comparing with untreated nymphs. Highly significant decline were recorded in them by mixture. Consult caused more increase in the total carbohydrates but Spinosad and the mixture caused decrease in the total carbohydrates comparing with untreated nymphs. Highly significant decline were recorded in carbohydrate content by Spinosad.