Abstract: Contents of total carbohydrate, trehalose, glycogen in diapausing larvae of the wheat midge, Sitodiplosis mosellana (Gehin) in various periods were examined, respectively. Results showed that there was no significant difference in the contents of total carbohydrates between 1st and 2nd year diapausing larvae. There were obvious differences in the content of total carbohydrates among larvae from the various seasons. The content of total carbohydrates in the mature larvae living on the wheat head was higher than that of larvae in the soil. Based on the change of total carbohydrate contents in the diapausing larvae, its development could be divided into two stages: Stage 1, from June to October; and Stage 2, from November to April of next year. There was lower content of carbohydrates in Stage 1 than that in Stage 2. Change trends of carbohydrate content in both cocooned and noncocooned larvae were similar in various periods. Content of trehalose in cocooned larvae in whole diapause period was kept on a higher level, and therefore the type of carbohydrate-alcohol accumulation of cocooned larvae of the wheat midge in diapause periods belongs to trehalose accumulation. The increasing content of glycogen was possibly related to diapause termination or change of diapause intensity in autumn and spring.

Key words: Sitodiplosis mosellana; diapause, total carbohydrate, trehalose, glycogen