ABSTRACT
The determinations of super-cooling ability and body' s water and fat contents of overwintering Hyphantria cunea pupae showed that during overwintering, 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).
