Abstract: The quantitative changes of glycogen and trehalose in the flight muscle, fat body and midgut as well as the trehalose level in the hemolymph of the adult armyworm Mythimna separata (Walker) during the initial period of flight were determined by means of TLC and colorimetric method. After one hour of flight the consumption of glycogen from the fat body reached the highest, accounting for about 80%-90% of the total carbohydrate consumed, and that from the midgut was rated the next. The amount of carbohydrate consumed from the flight muscle is so limited that as a fuel, it can only support flight for three minutes. During the flightperiod, concomitant with the decrease of trehalose concentration in hemolymph, the trehalose level in the flight muscle increased initially, decreased five minutes later, and reached a steady state at 15 to 30 minutes. However, the concentrations of trehalose in fat body and midgut decreased within 5 minutes at the beginning of flight, and then increased and approached a more or less constant level after thirty minutes of flight. The rate of carbohydrate metabolism in the male flight muscle was higher than that in the female.

Key words: Mythimna separata (Walker), flight muscle, fat body, midgut, he- molymph, glycogen, trehalose