多样化的棉田生态系统控害保益功能特征研究

应用数量分析与能量测定相结合的方法 ,定量地分析和比较了华北棉区多样化的套间作棉田生态系统与单作棉田生态系统中主要害虫、天敌的种群动态及其天敌对害虫的控制作用 .结果表明 ,多样化的套间作系统中苗蚜与 2代棉铃虫发生轻 ,而伏蚜与 3代棉铃虫发生重 ;套间作系统有利于天敌群落能量的生产 ,尤其是利于捕食性蜘蛛类群的能量生产 ;从棉田生态系统棉株 害虫 天敌相互作用关系来看 ,尽管间套作系统内天敌群落生产力增加 ,保护益虫 (天敌 )作用好 ,同时也增加了害虫群落生产力 ,其控害功能较差 .

Functional features of preserving natural enemies to control insect pests in intercropped cotton field ecosystems.

The population dynamics of insect pests and their natural enemies in single and intercropped cotton field ecosystems are analyzed, and the controlling effects of natural enemies in these ecosystems are compared. The results show that the population densities of cotton seedling aphids ( Aphis gossypii) and 2nd generation cotton bollworm ( Helicoverpa armigeria) are lower in intercropped than in single cotton field ecosystem, but those of summer aphids and 3rd generation cotton bollworms as well as the energy production of natural enemies (especially that of predacious spiders) are converse. From the viewpoint of function, the preservation effect on natural enemies is greater in intercropped than in single cotton field ecosystem, but the controlling effect of natural enemies on insect pests is converse.