不同温度条件下小菜蛾实验种群的研究

STUDIES ON THE LABOROTORY POPULATON OF DIAMONDBACK MOTH UNDER DIFFERENT TEMPERATURES

该文研究了１１种恒温（８～３５℃）对小菜蛾实验种群的存活、繁殖与种群增长的影响。结果表明，小菜蛾世代存活率与温度之间呈抛物线相关，以２５℃时的存活率最高。在３５℃及以上的高温下，卵不能孵化，蛹对８℃及以下的低温特别敏感。雌虫产卵期随温度的升高而缩短。８～３０℃下雌虫的繁殖动态可用类似于统计学的Ｇａｍｍａ分布函数来拟合。雌虫繁殖力和种群趋势指数与温度之间均呈抛物线相关，也均在２３℃时达到最大值。内禀增长率随温度的升高而增大，至３０℃时达到最大，随后则迅速下降，３５℃时降至零。

In this paper,the survival,reproduction and dynamics of the diamondback moth(DBM),Plutella xylostella(L.)were studied under l l scales of constant temperatures. The main results were followed:The survival rate of the generation of DBM,whichreached the maximum at 25℃,was parabolically related to temperature. The eggscould not hatch over 35℃. The pupae were particularly sensitive to lower than 8℃The oviposition duration of the females reduced with the increase of temperature. Theage-specific probabilities of the fecundities of the females at 8-30℃ could befitted with the equations similar to the density function of Gamma distribution in sta-tistics. The parabolical curves could well regress either the averge fecundity of the fe- male or the population trend index(I-value)of DBM laborotory population againsttemperature.The maximum average fecundity and the maximum I-value both ap-peared at 23℃,The intrinsic rate of increase of DBM ascended as temperautre be-came higher,and reached its maximum at 30℃,and then redueed dramatically whentemperature went up continuely.