Abstract: 【Aim】The purpose of this study is to explore the control efficacy of low-temperature stress on the cigarette beetle Lasioderma serricorne in cigars, and then to reveal the responses of the key cold tolerance substances in L. serricorne larvae to low temperature, so as to provide a scientific basis for the control of L. serricorne during cigar maintenance. 【Methods】Firstly, the mortality and corrected mortality of eggs, larvae, pupae and adults of L. serricorne were determined after exposure to varying low temperatures (0, -10 and -20 ℃) for different duration, respectively. The median lethal time (LT₅₀), 95% lethal time (LT₉₅) and 100% lethal time (LT₁₀₀) values of the low temperatures  0 and -10 ℃ to eggs, larvae, pupae and adults of L. serricorne were calculated. Subsequently, the changes in the contents of the cold-tolerance-related substances including trehalose, glucose and glycerol, in L. serricorne larvae after exposure to -10 ℃ for different duration were quantified. 【Results】Except the pupal mortality and corrected pupal mortality at -10 ℃, the mortality and corrected mortality of different developmental stages of L. serricorne in cigars after exposure to different temperatures for different duration increased significantly as compared with those in the control (test insects reared at 28 ℃). Complete death across all developmental stages of L. serricorne was achieved after exposure to 0 ℃ for 15 d, -10 ℃ for 72 h or -20 ℃ for 2 h. The cold tolerance of different development stages of L. serricorne varied, with larvae exhibiting the strongest cold tolerance, followed by adults, and pupae and eggs exhibiting relatively lower cold tolerance. The LT₅₀ values of the low temperature of 0 ℃ to eggs, larvae, pupae and adults of L. serricorne were 88.30, 128.65, 67.39 and 97.31 h, respectively. In addition, after exposure to -10 ℃, L. serricorne larvae displayed elevated trehalose and glycerol contents compared to the control, while the glucose contents in L. serricorne larvae decreased significantly after exposure to -10 ℃ for 12-72 h as compared to those in the control. 【Conclusion】 Low temperature can effectively control L. serricorne in cigars. Low temperatures of 0, -10, and -20 ℃ could completely kill L. serricorne in cigars, but the tolerance of L. serricorne to low temperature varies at different developmental stages, with larvae demonstrating relatively stronger cold tolerance. In addition, L. serricorne can adapt to the low temperature environment by regulating the levels of energy substances such as trehalose, glucose and glycerol in the body. This study provides theoretical and practical evidence for the application of low temperature technology in cigar maintenance to prevent and control L. serricorne, and offers a reference for further exploring the cold resistance mechanism of L. serricorne.

Key words: Lasioderma serricorne; low temperature, mortality, median lethal time, cold-tolerance-related substances