苜蓿套种与单种对昆虫种群动态及群落结构的影响

从单种、套种两种种植模式出发，初步探讨天敌、害虫在单种、套种两种基本模式下的发生规律，解决苜蓿种植模式调整后对苜蓿害虫影响情况不清造成苜蓿受害情况不明的问题，为指导宁夏地区牧草种植模式调整，促进苜蓿增产提供理论依据。采用网捕、诱集等方法搜集整理田间害虫、天敌种类和数量，通过典型性相关分析法对数据进行分析。结果表明：不同栽培模式下苜蓿草地中昆虫种类与个体数的差异很大，单种的苜蓿草地中害虫发生量普遍高于套种的苜蓿草地；单种的苜蓿草地中主要害虫的个体数普遍高于套种的害虫，优势天敌也同样表现出这种分布规律；单种的苜蓿草地生境中昆虫的总个体数、植食性昆虫的个体数以及捕食性昆虫的个体数都明显高于套种的苜蓿草地。套种苜蓿虫害、天敌变动规律较为复杂，除了种植模式之外，还需要采取多种手段防范因外部虫源引入造成的集中暴发。

Effects of intercropping and monoculture of alfalfa on population dynamics and community structure of insects

Abstract：The paper studied the occurrence pattern of the pests and their natural enemies in the alfalfa land with intercropping and monoculture. The study used the sweeping net and pitfall trap to collect insect samples. Results showed that the abundance and species of insect had a significant differences in different planting pattern of alfalfa. Pest damage was more serious in monoculture fields than that in intercropping fields. Furthermore, the abundance of natural enemies was higher in monoeulture fields than that in intercropping fields. In contrast, the community of insect was complex in intercropping alfalfa fields, which indicated that multiple management should be incorporated to protect alfalfa from pest damage.