Abstract: 【Aim】 This study aims to evaluate the influence of feeding different concentrations of exogenous trehalose on the survival and cold hardiness of adult Dastarcus helophoroides, an important and most effective natural enemy of longhorned beetles. 【Methods】 D. helophoroides adults were fed on a semi-artificial diets containing 3%, 6% and 9% trehalose, respectively, in the laboratory, and those fed on the semi-artificial diet without trehalose were used as the control group. After 10 weeks, the survival rate of adults was calculated. In addition, the supercooling point and water content of adults not subjected to low temperature treatment and subjected to low temperature treatment (10℃ for 3 d) were measured. 【Results】 The survival rate of D. helophoroides adults fed on the semi-artificial diets containing 6% trehalose was the highest (86.67%) among all the treatments. Whether subjected to low temperature treatment or not, D. helophoroides adults fed on the semi-artificial diet containing 9% trehalose had the lowest supercooling point as compared to those fed on the semi-artificial diet containing 3% and 6% trehalose and without trehalose (the control): the supercooling point of adults unsubjected to low temperature was -19.30℃, while that of adults subjected to low temperature treatment was -21.60℃. Low temperature treatment had a significant effect on the water content of adults fed on the diet without trehalose but no significant effect on the water content of adults fed on the semi-artificial diet containing trehalose. 【Conclusion】 Exogenous trehalose has significant influence on the survival and cold hardiness of D. helophoroides adults. Thus exogenous trehalose can be utilized to improve the survival rate and cold hardiness of D. helophoroides adults in laboratory rearing.

Key words: Dastarcus helophoroides, trehalose, survival rate, supercooling point, cold hardiness, water content