桑螟幼虫的越冬死亡率及过冷却点的研究

本文运用NTC-TD热敏电阻法测定了桑螟越冬幼虫的过冷却点、冰点。统计了桑螟幼虫的越冬死亡率。结果表明：前年9月到翌年4月间，过冷却点和冰点随温度降低而降低，随温度的升高而升高，并且均呈现一定的滞后性，但两者变化幅度不同，过冷却点的变化幅度显著大于冰点的变化幅度。4个处理中，越冬幼虫死亡率以枯枝落叶中为最高，室内最低。外界温度和过冷却点的变化，可能是引起桑螟死亡的重要原因。

Studies on the Death Rate through Winter and SCP of Over-wintering Larvae of Diaphania pyloalis

NTC-TD heat-sensitive resistance is used to measure the super cooling-point (SCP)and freezing point of over-wintering larvae of Diaphania pyloalis;death rate through winter is also countered.the result shows that during the September and the following April the SCP and freezing point of over-wintering larvae will go up and down with the changes of tempera-ture,both of them show the definite lagging with the changes of environmental temperature.But the variety ranges of them are different ,the changes of SCP is more remarkable than the later.In the4disposals,the death rate of the over-wintering larvae of is the highest in the shatters,the lowest in doors and in the middle in the slots of trees.The change of environement tem-perature and SCP is probably the main cause of the death.