中文摘要：

【目的】沙葱萤叶甲GalerucadaudcaJoannis于2009年开始在内蒙古草原暴发成灾，发生地区不断扩大，危害日趋严重，严重影响内蒙古草原畜牧业的可持续发展和生态安全。低温是影响昆虫生长发育和存活的关键因子，而昆虫对低温的耐受性决定了其越冬存活率。了解沙葱萤叶甲的过冷却点及抗寒能力有助于预测其分布范围及种群数量动态。【方法】采用热电偶法，在室内测定了沙葱萤叶甲各发育阶段的过冷却点；比较了幼虫在不同低温条件下（-6--14℃）暴露2h及在-5°C低温条件下暴露不同时间（0．5-8d）的存活率。【结果】沙葱萤叶甲不同发育阶段的过冷却点存在显著差异，从低到高依次为卵（-29．8°C）、1龄幼虫（-14．6℃）、2龄幼虫（-13．3°C）、蛹（-12．1℃）、3龄幼虫（-10．2℃）和成虫（-9．O°C）；越冬卵12月和1月的过冷却点最低，2月的过冷却点最高。随着处理温度的降低和处理时间的延长，幼虫的存活率降低。1，2和3龄幼虫在-5℃下的半致死时间（Ltime∞）分别为3．84，3．80和2．28d，低温处理2h后半致死温度（Ltemp50）分别为-10．1，-9．1和-8．5°C，高于其过冷却点。【结论】说明沙葱萤叶甲幼虫为不耐寒冷型（chill-intolerant）。

英文摘要：

[ Aim] C, aleruca daurica Joannis began to outbreak seriously since 2009 and has caused great losses in the Inner Mongolian grasslands. Its occurrence region has expanded constantly and the damage has become more and more severe, which greatly influenced the sustainable development of grassland animal husbandry and ecological safety in Inner Mongolia. Low temperature is a key factor that affects the development and survival of insects, and their overwintering survival mainly depends on their tolerance to low temperature in winter. Understanding the supercooling point （SCP） and cold hardiness of G. daurica is helpful to forecast its distribution and population dynamics. [ Methods ] We measured the supercooling points in various developmental stages in the laboratory and determined the survival rates of larvae exposed to different low temperatures （ -6°C - -14°C ） for 2 h or exposed to -5°C for different periods （0.5 -8 d） with the thermocouple method. [ Results ] The supercooling points had obvious differences among various developmental stages of G. daurica in the following order from low to high： egg （ -29.8°C）, 1st instar larva （ - 14.6°C）, 2nd instar larva （ - 13.3°C）, pupa （ - 12. ICE）, 3rd instar larva （ - 10.2°C ） and adult （ - 9.0°C ）. The SCPs of eggs were the lowest in December and January, and the highest in February. The survival rates of larvae declined with the decrease of treatment temperature and the extension of treatment time. For 1st instar, 2nd instar and 3rd instar larva, the half lethal time of individuals （ Ltim%0 ） at - 5 °C was 3.84 d, 3.80 d and 2.28 d, respectively, while the lower lethal temperature needed to kill 50% of individuals （ Ltemp50 ） after 2 h exposure was - 10. 1 , - 9.1 and - 8.5°C, respectively, higher than the corresponding SCPs. [ Conclusion ] The larvae of G. daurica can be considered as chill-intolerant.