摘要
1988～1989年,在兰州市农科所和榆中县园艺场对1983年以来释放过西方盲走螨的苹果园及其周围进行了调查。结果表明,该螨已在兰州地区自然越冬,建立种群。1983～1987年先后重复释放面积为9亩,1988年自然发生面积21亩,1989年达41亩,对李始叶螨发挥良好的控制效果,年施药次数可减少2～3次。在地下土缝、地表覆盖物和枯枝落叶丛中越冬的西方盲走螨,是兰州地区自然发生的主要虫源。西方盲走螨越冬成功与否,与越冬前和出蛰期的食料条件,及其活动期使用化学药剂的影响密切相关。
M. occidentalis was released repeatedly every year in an area of 0.6 ha during 1983-1987 in several apple orchards of Lanzhou and Yuzhong to control the leafmite, E. pruni.. Studies in these orchards in 1988-1989 confirmed that the predator has established its natural populations in this region, and played an important role in suppressing the leaf mite populations.The predator was found to have dispersed to 1.4 ha by 1988, and to 2.7 ha by 1989. Comparing to the non-released orchards, chemical spray against E. pruni. in the released orchards was reduced by 2-3 times annually. The predator overwintered in ground crevices, under dry leaves and plant debris, and became the population source for the following spring. The nutrient availability pre- and post-overwintering, as well as pesticide applications in growing seasons were found to be critical in influencing the population fluctuations of the predator in the orchards.
关键词
叶螨
西方盲走螨
苹果园
定殖
防治
Metaseiulus occidentals, Eotetranychus pruni colonization
