The desert locust is a very destructive herbivore causing considerable loss to crops and pastures in the arid and semi-arid areas of Africa and Asia. M. anisopliae fungus strain is highly specific biopesticides to locusts and grasshoppers, and is safe to non-target invertebrates. To test the effect of M. anisopliae fungi on the Locusts mortality, biochemistry and physiology, fungi at doses 103 , 106 and 1012 spores/ml were applied with two different treatment methods; fungi spray and fungi soil application. The insects were treated under either non-starvation and/or starvation conditions. Mortality, total proteins, carbohydrates and lipids contents of insects were measured. All the locust nymphs were susceptible to M. anisopliae, with high mortality rate recorded. The insect enzymes Phenoloxidase, Peroxidase activities were affected, fluctuated between increasing and decreasing by fungi infection. Total insect proteins, carbohydrates and lipids contents were dramatically declined in all treatments. The results indicated physiological and biochemical changes in the locusts in return to fungi infection.