美国白蛾过冷却点的影响因子

Factors affecting Hyphantria cunea supercooling point

美国白蛾是一种重要的国际检疫害虫,作为外来入侵生物在中国不断扩散蔓延。过冷却点是研究其潜在适生区重要的生理指标之一。本文研究了不同虫态、寄主树木、低温驯化时间和地理种群与过冷却点的关系。结果表明:美国白蛾不同虫态过冷却点间存在显著差异(P<0.001),蛹期过冷却点最低(-15.91℃),5龄幼虫的过冷却点最高(-6.97℃),过冷却点随虫态龄期增加而升高;用悬铃木饲养的美国白蛾蛹的平均过冷却点为-16.09℃,显著低于复叶槭饲养的美国白蛾蛹的平均过冷却点-14.61℃(P=0.002);在6℃下分别驯化美国白蛾非滞育蛹24、48和72 h,美国白蛾非滞育蛹过冷却点无显著差异(P=0.846);武邑、内黄、濮阳、东营、寿光和沈阳6个不同地理种群美国白蛾蛹的过冷却点间存在极显著差异(P<0.001),其中内黄地区美国白蛾过冷却点最低(-21.39℃),东营地区过冷却点最高(-15.35℃)。

As an alien invasive species in China,Hyphantria cunea is an important international quarantine pest and its distribution is spreading. The supercooling point（ SCP） is an important physiological indicator for studying its potential distribution area. In this study,we analyzed the relationships between SCPs and larvae instars,host plants,low temperature acclimation time and geographical population. It was found that the SCP of H. cunea differed with larvae instars（ P〈0.001）. The lowest SCP was found in pupae（-15.91 ℃） and the highest SCP was found in5 th instar（-6.97 ℃）; SCP increased with the increase in age of larvae instars. The averaged SCP of H. cunea pupae feeding on the leave of Platanus acerifolia（-16.09 ℃） was significantly lower than that of pupae feeding on the leave of Acer negundo（-14.61 ℃）（ P = 0.002）. There was no significant difference in SCP of non-diapause pupae after acclimating 24,48 and 72 h at6 ℃（ P = 0. 846）. Significant differences of SCP were found among 6 geographic populations（ Wuyi,Neihuang,Puyang,Dongying,Shouguang and Shenyang）. Particularly,the SCP of Dongying samples was the highest（-15. 35 ℃） and the SCP of Neihuang was the lowest（-21.39 ℃）.