蔬菜害虫及其天敌昆虫群落多样性和相关性研究

在比较脆弱的菜田生态系统中，蔬菜害虫和天敌如果没有人为防治的干扰，天敌群落和害虫群落在结构上有动态的消长规律。江淮地区蔬菜害虫主要为菜缢管蚜(Brevicoryae brassicae)、瓜绢螟(Diaphania indica)、朱砂叶螨(Tetranychus cinnabarinus)及桃蚜(Myzus persicae)等；昆虫天敌主要为异色瓢虫(Harmonia axyndis)、广赤眼蜂(Trichogramma evanescens)及七星瓢虫(Coccinella septempunctata)等。8月下旬～9月下旬，菜田昆虫种类丰富、个体发生量大，多样性指数及均匀度指数较大。经典型相关分析，蔬菜害虫和天敌群落间典型相关系数达极显著水平，其中载荷较大的指标为多样性指数和均匀度，即两个群落结构间的相关，主要是多样性指数和均匀度的相关。

Studies on the diversity and correlation between the communities of vegetable insect pests and their natural enemies

Without chemical control, the communities of vegetable insect pests and their natural enemies had apparently dynamic relationships. In Jianghuai area, the pest community mainly included Brevicoryae brassicae, Tetranychus cinnabarinus, Diaphania indica and Myzus persicae, while the natural enemy community chiefly composed of Harmonia axyndis, Coccinella septempunctata and Trichogramma evanescens. Number of species and individuals of insects reached a climax between late August and late September, and the indexes of evenness and diversity of insect community were above 2.5 and 0.7 respectively. The authoritative coefficient between the communities of pests and natural enemies reached significant level. The the correlation between the two communities was mainly dependent on the index of diversity and evenness, which had higher values loading in correspondent communities.