Abstract: In this study the authors using Nosema locustae as a parasite on Locusta migratoria manilensis, measured the content of glyceride and lipase activity in haemolymph and the total fat of the locust infested. The results manifest that N. locustae can cause the content of glyceride in haemolymph and the total fat of L. migratoria manilensis decline rapidly and the lipase activity in haemolymph rise rapidly. A new identifying method of grade of disease according to the physiological guideline is suggested.

Key words: Locusta migratoria manilensis, Nosema locustae, glyceride, lipase, grade of disease