美国白蛾越冬蛹的过冷却能力、体内水分及脂肪含量

Super-cooling ability and its relations to body's water and fat contents of overwintering Hyphantrian cunea(Lepidoptera:Arcidae) pupae

对美国白蛾(Hyphantrian cunea)越冬蛹在越冬过程中过冷却能力、体内水分及脂肪含量的变化进行了研究.结果表明:在越冬过程中,美国白蛾雌、雄蛹的抗寒能力呈现出相似的变化趋势,即其抗寒能力随越冬期温度降低而逐渐增强,并在冬季过后随温度升高而逐渐减弱.越冬期不同阶段越冬蛹体内水分、脂肪含量及过冷却点(SCP)和结冰点(FP)有所不同.其中,越冬前期和中期的SCP显著低于越冬后期,FP没有显著性差异;越冬中期蛹体内含水量最高,显著高于越冬前期和后期.越冬蛹的SCP和FP均显著低于非越冬蛹,体内水分和总脂肪含量均明显高于非越冬蛹.经回归分析,雌、雄蛹体内含水量与其SCP呈较好的负相关关系(P<0.05).

The determinations of super-cooling ability and body＇ s water and fat contents of overwintering Hyphantria cunea pupae showed that during overwinter/ng, the female and male H. cunea pupae had the similar change patterns in their cold-resistance ability, i. e. , increased with decreasing air temperature, but their body＇s water and fat contents, super-cooling point （SCP）, and freezing point （FP） differed at different overwintering stages. The SCP was significantly lower at pre- and mid-overwintering stages than at late-overwintering stage, while FP had less difference among the stages. The body＇s water content was significantly higher at mid-overwintering stage than at pre- and late-overwintering stages. Comparing with non-overwintering pupae, the overwintering pupae had significantly lower SCP and FP, but significantly higher body＇ s water and total fat contents. Regression analysis showed that there was a negative relationship between the water content and the SCP of female and male pupae （ P 〈 0. 05 ）.