Abstract: 【Aim】Recent warmer climate caused persistent outbreaks of Siberian grasshopper, Gomphocerus sibiricus (L.), in Xinjiang. This study aims to explore the potential physiological and biochemical mechanisms of G. sibiricus exposed to high temperature. 【Methods】The contents of trehalose, glycerine, oleic acid, linoleic acid, and linolenic acid accumulated in adult grasshopper bodies were measured after these locusts had been placed in climate cabinet under consistent temperature regimes of 24-42℃ at 3℃ intervals for 4 h. 【Results】The contents of trehalose, glycerine, oleic acid, linoleic acid, and linolenic acid in G. sibiricus increased with temperature ranging from 24 to 30℃, and reached the peak at 30℃, with the contents of 18.691 μg/g, 261.432 μg/g, 79.063 mg/g, 78.664 and 227.593 mg/g, respectively. The contents of trehalose, glycerine, oleic acid, linoleic acid, and linolenic acid in G. sibiricus began to decrease as the temperature rose further, and reached the lowest at 42℃, with the contents of 18.218 μg/g, 104.588 μg/g, 4.343 mg/g, 3.093 mg/g, and 11.067 mg/g, respectively. The accumulation rates of these stress resistant substances were different with temperature increasing. The content of linolenic acid increased dramatically (832.189%) while that of trehalose accumulated increased slightly (0.893%). The content of linoleic acid had a significant decrease (63.988%) while that of trehalose reduced slightly (0.224%). 【Conclusion】The higher the temperature above 30℃, the higher the locust mortality. This study demonstrated that with the temperature increasing in a certain range, G. sibiricus can adapt to higher temperature conditions by regulating the contents of stress resistant substances, especially the unsaturated fatty acids, and thus remains a serious pest to the steppe in Xinjiang under the trend of climate warming.

Key words: Gomphocerus sibiricus; temperature, stress resistant substances, trehalose, glycerine, unsaturated fatty acids