昆仑山极端环境草地螟越冬场所选择及耐寒适应性研究

The meadow moth,Loxostege sticticalis(Lepidoptera:Pyralidae),is one of the most destructive pests in northern China.It has broken out three periodicities since 1949 and led to huge economic loss to agriculture and pasturage.New characteristics such as more serious damage and more overwintering locations,especially in higher elevation and latitude area appeared in the third period(from 1996s).Lots of overwintering larvae were found from 3000m to 3500m of Kunlun Mountains since 2008, which is the highest elevation overwintering habitat for the moth at home and abroad. However,the current progresses in the moth researches could not clearly explain the moth how to spend the cold season in Kunlun Mountain,where the extreme cold temperature could be minus 30℃ or even less. .This project will be focused on the meadow moth wintering habitat selection and its adaptation to the extreme cold weather conditions of Kunlun Mountains.During the overwintering season,the supercooling points(SCP),freezing point(FP),water content,fat,fatty acid,glycrol,total sugar and protein in the larvae samples collected from Kunlun Mountain at different months will be determined. .The project is aimed: .1) to understand environmental factors,including elevation,vegetation, topography,slope,soil,etc.,how to affect wintering habitat selection by the moth via ecological technique and method. .2) to determine the lower limit of thermal tolerance and to find dynamic changes of cold-hardiness indices and cold-resistance substances with environmental temperature changes during overwintering season,and explore the biochemical and physiological mechanism of cold-hardiness adaptation for the meadow moth. .The results would provide some scientific theoretic evidence for enhancing the forecast for the pest in higher elevation and latitude area.

草地螟(Loxostege stictical L.)是我国东北、华北和西北地区的重要农牧业害虫，新中国成立以来已经三次暴发成灾，相对于第一（1953-1959年）和第二个（1978-1984年）暴发周期，草地螟在第三个暴发周期（1996-）的危害更为严重，并出现了新的变化特点和发展趋势。尤其在新疆昆仑山海拔3000-3500m的区域发现高密度草地螟越冬虫源，这也是目前国内外海拔最高的草地螟越冬区，而已有草地螟的相关研究结果无法解答草地螟是如何度过昆仑山-30℃甚至更加极端寒冷条件的客观事实。我们基于前期工作基础，运用生理生化及实验生态学方法与手段，旨在阐明影响昆仑山草地螟种群越冬场所选择的外部环境因子，分析昆仑山草地螟种群在极端低温环境选择压力下，其低温耐受极限及体内抗寒物质组分与含量的变化规律，揭示昆仑山草地螟种群的耐寒适应机理，以期为高海拔区域草地螟预测和防治提供科学依据。