陇南桔园昆虫群落生态位及时序动态研究

The Niche and Timedynamic Analysis of Insect Community in Citrus Orchard of South Gansu province

报道了陇南桔园昆虫群落生态位和时序动态规律。用群落生态方法探讨了各种群的竞争共存机制。结果表明，４种主要害虫在树冠上各占据相应的生态位。矢尖蚧和吹绵蚧的竞争主要表现在空间分化上；桔全爪螨占有较大的空间，而在时间序列上出现频率小；桔蚜占据较小的空间。在天敌因素中，瓢虫类表现出较小的空间占有量和较长的时间占有量，而草蛉正好相反。草蛉类与桔全爪螨、瓢虫类与吹绵蚧，以及两类天敌与矢尖蚧的生态位重叠值均较大，说明它们在时间维度上的同步性和在空间维度上的同域性，以及它们在猎物上的选择性。两类天敌既各有所喜好的捕食对象，又有共同的捕食对象，当竞争加剧时，其捕食对象分化也加剧。按桔园昆虫群落时序动态规律将桔园害虫管理分为３个有序阶段，以提高生态控制作用。

This paper discussed the competitive and coexistent mechanisms of dominant populations on the basis of studying their spatial and time niches.The results showed that four dominant pest had their own niches in crown of citrus tree.The competition of Unaspis yanonensis Kuwana and Icerya purchasi Mask focused on spatial differentiation;panonychus citri Mcgregor occupied larger spatial and shorter time dimension;citrus aphid occupied smaller spatial dimension. In the factor of natural enemies, ladybirds had a smaller spatial and longer time dimensions, lacewings were on the contrary.The value of niche overlap of timespatial two dimensions between lacewing and Panonychus citri Mcgregor, ladybird and Lcerya purchasi Mask,two kinds of natural enemies and Unaspis yanonensis Kuwana indicated their population had symchrony in time and sympatry in spatial dimension,as well as revealed two kinds of natural enemies had their own favorite and mutual preys.When the competition became violent, their preys trend to differentiation. The pests management of citrus orchard was divided into three sequential phase according to the timedynamic of insect community.