美国白蛾Hyphantria cunea(Drury)越冬蛹的抗寒性研究

Cold Hardiness of the Overwintering Pupae of Fall Webworm Hyphantria cunea(Drury)(Lepidoptera: Arctiidae)

基于为控制美国白蛾Hyphantria cunea(Drury)对桑树和柞树的的危害提供理论依据,测定了美国白蛾越冬蛹不同时期的过冷却点和含水量。结果显示,越冬蛹的过冷却点以2月份最低,为(-27.07±0.38)℃,11、12月份最高,分别为(-20.38±2.26)℃和(-22.99±4.03)℃;含水量以11、3月最高,分别为67.03%和65.07%,1月份开始下降,2月份降至最低30.76%,3月份又增加到45.95%。含水量的变化与过冷却点的变化趋势相似,含水量的下降降低了越冬蛹的过冷却点,可增强其抗寒能力。

To provide theory evidence for developing the control method of Hyphantria cunea （ Drury）, the supercooling point and water content of the overwinter pupae were determined at different periods, Results showed that the least supercooling point was in February （ -27.07 ±0.38） ℃, and the highest ones was in November and March [ （ -20.38 ±2.26） ℃ and （ -22.99 ±4.03） ℃, respectively]. The highest water content was in November and December （67.03% and 65.07%, respectively）. The water content started to decrease in January, reached to the lowest （30. 76% ） in February and increased to 45.95% in March. Change trendency of water content was similiar with that of the supercooling point. The results revealed that decreasing of water content in overwintering pupae resulted in the decrement of supercooling point, which led to enhance the ability of cold hardiness.