苹果梨树上山楂叶螨积群动态分析

THE POPULATION DYNAMICS OF Tetranychus viennensis Zachero ON APPLE-PEAR TREES

内蒙古河套地区山楂叶螨以受精雌成螨在树干、主枝翘皮下及根茎附近的缝隙内越冬。越冬雌成螨出蛰高峰在４ 月下旬苹果梨花芽开绽期，出蛰时间长达１ 个月。一代卵高峰期在５ 月中、下旬，一代若螨发生盛期在５月下旬。从雌成螨数量消长来看，在苹果梨上全年有４ 次危害高峰，相应物候期为开花—座果期、新梢生长高峰期、花芽分化期和果实生长后期。

Tetranychus viennensis in Hetao region in Inner Mongolia hibernated in the stems and below the warped barks of main branches and in the cracks near the root in fertilized female adult mite.The revival peak of hibernating female adult mites was in the last ten-day period of April which was just the flower bud-blooming stage of apple-pear trees.The revival time lasted for almost one month.The occuring peak of the first generation eggs was in the middle and last ten-day periods in May.The first generation nymphs flourished in the last ten-day period in May.From the population dynamics of female adult mites,they had four peaks on apple-pear trees within one yiar,whose corresponding phonophases were blooming-fruit setting stage,growing peak of new tips of trees,flower bud differentiating stage and fruit growing later-stage respectively.