高温胁迫对白眉野草螟滞育幼虫存活特性的影响

Effects of high temperature stress on the survival characteristics of the diapause larvae of Agriphila aeneociliella( Lepidoptera: Pyralidae)

[目的]白眉野草螟Agriphila aeneociliella是小麦上新发现的一种害虫,以滞育的老熟幼虫做土茧在土壤中越夏,研究明确滞育幼虫在夏季持续高温和极端高温条件下的存活率,为该害虫秋季虫源基数的预测预报和有效防控提供依据。[方法]以白眉野草螟带土茧滞育幼虫和不带土茧滞育幼虫为研究对象,在室内条件下设置43,46,49,52和55℃极端高温,分别处理0.5,1,2和4 h;设置35,37,39和41℃普通高温,分别处理1,2,4和8 d。[结果]极端高温处理2和4 h后,带土茧滞育幼虫半致死温度分别为50.04℃（95%置信区间：49.36～50.47℃）和48.81℃（95%置信区间：47.74～49.37℃）,去除土茧后分别为48.20℃（95%置信区间：47.66～48.74℃）和47.36℃（95%置信区间：47.08～48.37℃）;52℃温度条件下,带有土茧滞育幼虫半致死时间为1.29 h（95%置信区间：1.17～1.44 h）,去除土茧后半致死时间为1.02 h（95%置信区间：0.93～1.18 h）。普通高温处理41℃时,带有土茧滞育幼虫半致死时间为3.21 d（95%置信区间：2.92～3.52 d）,去除土茧后半致死时间为2.66 d（95%置信区间：2.33～3.02 d）。[结论]白眉野草螟滞育幼虫具有很强的耐高温能力,土茧对其具有一定的保护作用。小麦收割后深耕灭茬,使土茧或幼虫裸露到地表,利用夏季土表高温杀死滞育幼虫,可以作为一项有效的农业防治措施。

[Aim ] Agriphila aeneociliella is a new pest of wheat crops,which survives summer as diapausing larvae making cocoon in soil. This study aims to determine the survivorship of A. aeneociliella in sustained high temperature and extreme high temperature in summer,so to provide a basis for population monitoring and management in autumn. [Methods]The diapause and non-diapause larvae of A. aeneociliella were subjected to extreme high temperatures（ 43,46,49,52 and 55℃） for 0. 5,1,2and 4 h,and to the common high temperature（ 35,37,39 and 41℃） for 1,2,4 and 8 d,respectively.[Results]Semi-lethal temperatures of diapause larvae with cocoon of A. aeneociliella were 50. 04℃（ 95% confidence interval： 49. 36- 50. 47℃） and 48. 81℃（ 95% confidence interval： 47. 74-49. 37℃）,and those with cocoon removed were 48. 20℃（ 95% confidence interval： 47. 66- 48. 74℃）and 47. 36℃（ 95% confidence interval： 47. 08- 48. 37℃） when subjected to the extreme high temperature for 2 and 4 h,respectively. The median lethal time of diapause larvae with cocoon was 1. 29 h（ 95% confidence interval： 1. 17- 1. 44 h）,and that with cocoon removed was 1. 02 h（ 95% confidence interval： 0. 93- 1. 18 h） when subjected to the extreme high temperature of 52℃. The median lethal time of diapause larvae with cocoon was 3. 21 d（ 95% confidence interval： 2. 92- 3. 52 d） and that without cocoon was 2. 66 d（ 95% confidence interval： 2. 33- 3. 02 d） when subjected to the common high temperature at 41℃. [Conclusion]A. aeneociliella has a strong tolerance to high temperatures,and cocoon has a protective effect on diapausing larvae. Ploughing and stubble cleaning to make cocoons or larvae exposed to the soil surface after wheat harvesting,which takes advantage of high temperature of soil surface to kill diapause larvae,can be used as an efficient agricultural control measure.