中文摘要：

【目的】探索双委夜蛾Athetis dissimilis（Hampson）的耐寒策略及越冬虫态。【方法】以室内双委夜蛾种群为虫源,分别测定3龄、4龄、5龄、6龄和老熟幼虫以及蛹的过冷却点（supercooling point,SCP）、结冰点（freezing point,FP）、含水量以及脂肪、蛋白质、甘油、山梨醇和海藻糖含量。【结果】不同龄期幼虫和蛹之间过冷却点和结冰点存在显著差异,低龄幼虫SCP和FP较高;随着龄期增长,二者均降低,老熟幼虫的SCP和FP最低,分别为-18.20℃和-11.72℃。不同龄期幼虫和蛹的生化物质含量均存在显著差异。随着龄期的增加,含水量和甘油含量呈降低的趋势,蛹的含水量（65.33%）和甘油含量（154.90μg/mg）最低;脂肪和蛋白质含量随龄期的增加呈现增加的趋势,蛹的脂肪和蛋白质含量最高,分别为25.36%和2 298.37μg/mg。老熟幼虫海藻糖含量相对较高（57.28 mg/g）,而山梨醇含量较低（15.49 mg/g）。【结论】与其他龄期相比,双委夜蛾老熟幼虫和蛹的耐寒性最强,是最可能的越冬虫态;脂肪、蛋白质和海藻糖可能是双委夜蛾重要的耐寒物质。

英文摘要：

【Aim】 This study aims to explore the cold tolerance strategies and overwintering stage of Athetis dissimilis （Hampson）. 【Methods】 The supercooling point （SCP）, freezing point （FP）, and the contents of water, fat, protein, glycerin, sorbitol and trehalose in the 3rd, 4th, 5th, 6th instar and mature larvae, and pupae of A. dissimilis were measured in the laboratory. 【Results】 The SCP and FP had obvious differences among different instar larvae of A. dissimilis, and the SCP and FP of young larvae were higher than those of old larvae. The SCP and FP of mature larvae dropped to the lowest （-18.20℃ and -11.72℃, respectively）. There were significant differences in the contents of biochemical substances between different instar larvae. The water and glycerin contents declined with the increase of developmental stage. The lowest water and glycerin contents were found in pupae （65.33% and 154.90 μg/mg, respectively）. There was a trend of increase of fat and protein contents with the increase of developmental stage. The fat and protein contents in pupae （25.36% and 2 298.37 μg/mg, respectively） were higher than those in larval stages. The trehalose content in mature larvae was relatively high （57.28 mg/g）, while the sorbitol content was relatively low （15.49 mg/g）. 【Conclusion】 The strongest two cold-tolerant stages of A. dissimilis were mature larva and pupa, which may be more suitable for overwintering than other developmental stages. Fat, protein and trehalose may be the important cold-resistant substances in A. dissimilis.