Abstract: 【Aim】 This study aims to analyze the contents of biochemical substances used as energy sources in the English grain aphid, Sitobion avenae (Fabricius) to provide a foundation for future biochemical and physiological studies of its energy adaptation to starvation stress. 【Methods】 With the aphids fed on wheat seedlings as the control, the fresh body weight, dry body weight, and the contents of water, soluble sugars, glycogen, total lipids, and soluble proteins in alate S. avenae adults under starvation stress were measured, and the changes of energetic metabolism were analyzed by correlations between the contents of various biochemical substances. 【Results】 The fresh body weight (5.30-8.73 mg/20 individuals) and dry body weight (1.67-3.10 mg/20 individuals) of alate S. avenae adults in the starvation group were lower than those in the feeding group (7.93-8.73 and 2.53-3.10 mg/20 individuals, respectively) at the same day after emergence. The water contents in the starvation and feeding groups were 63.16%-71.76% and 63.25%-67.32%, respectively. Except for the 1st day after emergence, the starved aphids had higher water content than the feeding aphids at the same day after emergence. The contents of soluble sugars, glycogen, total lipids, and soluble proteins in the starvation group were 6.60-11.21, 0.35-10.81, 18.28-30.42, and 12.77-33.44 μg/mg fresh body weight, respectively, which were lower than those in the feeding group at the same day after emergence (7.53-11.21, 3.66-10.81, 27.53-33.63, and 21.54-34.43 μg/mg fresh body weight, respectively). After newly emerged aphids were starved for 3 d, their fresh body weight, dry body weight, and the contents of water and glycogen increased, whereas their contents of total lipids and soluble proteins decreased on the 1st day after resuming feeding. There was a positive correlation between the content of soluble sugars and the content of glycogen, total lipids, or soluble proteins as well as between the content of soluble proteins and the content of glycogen or total lipids in the starvation group. 【Conclusion】 The results suggest that changes of energy metabolism under starvation stress are associated with the decrease of contents of glycogen, total lipids, and soluble proteins in alate S. avenae adults. Aphids use a mixture of energy sources to adapt to brief starvation stress when they are starved.

Key words: Sitobion avenae, starvation stress, body weight, biochemical substances, energy source, energy adaptation