The measurements of the hind femur and activities of five enzymes (α-glucosidase, amylase, cellulase, proteinase and lipase) were determined in the femoral muscles of all post-embryonic developmental stages of Zonocerus variegatus (Linnaeus). The length, width and weight of the hind femur increased during the post-embryonic developmental stages. The enzymatic activities in the femoral muscles of the adult stage were significantly (P < 0.05) higher than the lower instar stages. Proteinase and lipase activities were higher than the carbohydrases (α-glucosidase, amylase and cellulase), reflecting the nature and composition of the food plants consumed.