Abstract: Contents of glyceride, glycogen and water in various stages of the adult ori ental armyworm, Mythimna separata (Walker), as affected by larval rearing densities (1, 20, 40 larvae/jar (850 mL)) were studied in laboratory conditions. Glyceride levelin the newly emerged adults from crowded larvae was significantly higher than that from isolated ones, even though it was insignificantly different in adults from 20 and 40 larvae/jar. Differences in glyceride levels also occurred in later stages of the adult life. Glyceride contents in both male and femlae adults from isolated larvae were significantly greater than those from crowded larvae on the 1st d of the adult life. Situations, however,inversely changed by the 3rd and 5th d of the adult life. Glycogen and water con-tents in the newly emerged adults were insignificantly affected by larval rearing densities, but were significantly affected in later stages of the adult life. Water contents in adults from 40 larvae/jar were significantly higher than that from isolated larvae on thelst and 5th d of adult life. Glycogen level in I-day-old male adults from 40 larvae/jar was significantly higher in comparison with that from isolated and the other larval rear ing densities. Besides, glycogen content in female adults from crowded larvae was increased, but that from isolated ones was decreased as the adult's age increased. These results indicate that larval rearing density affects the levels of energetic sources not only in the newly emerged adults, but also in later stages of the adult life. Significance of the study'is discussed in light of published findings.

Key words: Mythimna separata, larval density, glyceride, glycogen