不同类型棉田捕食性天敌的种群能量动态及其对害虫的控制作用

为充分发挥棉田捕食性天敌的生态调控作用，本文根据田间调查与室内测定的结果，以能量为统一单位，计算出了棉田捕食性瓢虫、蝽类、蜘蛛及所有捕食性天敌类种群的能流参数值，分析和比较了不同播种期、套间作和免耕法对棉田捕食性天敌种群能量获取利用的作用特点，总结出了各类天敌在不同类型棉田对害虫的控制作用规律，评价了它们在棉田生态系统中的作用与地位。

THE POPULATION ENERGY DYNAMICS OF PREDACIOUS NATURAL ENEMIES AND THEIR PEST CONTROL ACTIVITY IN DIFFERENT COTTON AGROECOSYSTEMS

To bring the pest control activity of predacious natural enemies into good play on cotton, a series of field investigations and indoor tests were carried out for getting their population dynamics along with the development of cotton in eight different cotton agroecosystems, and the energy currency parameters of the populations of predacious ladybirds, bugs, spiders and whole predators were calculated according to a unified energy unit. The characteristics of energy intake and exploitation of each predacious natural enemy population in different types of cotton fields with different sowing times, intercropping and tillage systems were analysed and compared with each other. The dynamic regularities of pest control activities and the functions and locations of different predacious natural enemies in different cotton agroecosystems were summarized and evaluated.