华丽肖蛸和锥腹肖蛸不同龄期饥饿耐受性研究

Study on the starvation endurance of the different instars of Tetragnatha nitens and Tetragnatha maxillosa

【目的】测定华丽肖蛸Tetragnatha nitens和锥腹肖蛸Tetragnatha maxillosa在实验条件下的耐饥力,确定其龄期与耐饥力之间的关系,为稻田害虫综合防治提供理论依据。【方法】实验条件:不供食物、实验温度为25℃,在人工气候箱内饲养并饥饿华丽肖蛸和锥腹肖蛸的幼蛛及成蛛。华丽肖蛸和锥腹肖蛸根据龄期分别设置3个处理组以及与每个处理组对应的对照组,每3 d统计死亡率。【结果】饥饿状态下华丽肖蛸和锥腹肖蛸的存活时间与体重之间相关性是极显著的;华丽肖蛸和锥腹肖蛸各自3个不同龄期组的存活时间具有极显著差异;华丽肖蛸和锥腹肖蛸对应的3个相同龄期组的存活时间无显著差异;不同龄期组幼蛛的阶段成活率与存活时间之间符合二次抛物线关系。用拟合曲线得出华丽肖蛸的饥饿半致死时间(t50)和致死时间(t95)分别为22 d和32 d;锥腹肖蛸的饥饿半致死时间(t50)和致死时间(t95)分别为20 d和28 d。【结论】华丽肖蛸和锥腹肖蛸的幼蛛在没有食物的实验条件下,具有一定的耐饥饿能力,仍可存活一定的时间。

[Objectives] This study aimed to test the starvation endurance of different instars of Tetragnatha nitens and Tetragnatha maxillosa. [Methods] Three different instars of these spiders were kept without prey in a laboratory at 25℃. Three treatment groups and three control groups for each instar were established according to mortality statistics recorded every three days. IResults] There was a marked correlation between larval weight and survival time of T. nitens and T. maxillosa and survival times of the three different instars were significantly different. The relationship between instar survival rate （v） and survival time （t） fitted a parabolic curve. The t50 arid t95 starvation endurance thresholds for T. nitens were 22 and 32 days. The t50 and t95 starvation endurance thresholds for T. maxillosa were 20 and 28 days. [Conclusion] T. nitens and T. maxillosa can effectively survive a sudden drop in prey numbers in paddy fields following pesticide application or tilling.