棉田捕食性瓢虫控害功能的分析

在系统调查棉田捕食性飘虫种数量动态的基础上，应用生态能学的方法，分析并比较了不同插种期、套间作等农业措施对棉田捕食性飘虫控害虫功能的影响。结果表明，不同类型棉田飘虫对害虫的摄入量为26．45－70kJ.m^-2，分别占整个捕食性在天敌摄入量的28．30％－47．88％，是棉田捕食性天敌的优势种类；不同类型棉田飘虫对棉蚜的控害系数为5．07％－12．85％，并随着棉花播种期的推后和间套作呈现出下降趋势，它们在棉田生态系统害虫生态调控中发挥着重要作用。

Biological control efficiency of ladybirds on arthropod pests in cotton Agroecosystems

Based on the systematical investigation of population dynamics of predacious ladybird in different cotton agroecosystem, the energy flow for predacious ladybirds was analyzed by the way of ecological energetic. The biological control efficiency of ladybirds was compared in different planting-time and inter-crop cotton agroecosystems using available date on the prepapers of ladybird ingestion to pest production. The results showed that the ingestion of predacious ladybirds were 26.45-70 kJ.m-2 yr.-1, accounting for 28.30-47.88% of all predacious natural enemies in different cotton agroecosystems. The biological control efficiency of ladybirds to aphids were 5.07-12.85%, which was decreased in inter-crop cotton agroecosystems and the ecosystems with the delay of planting-time. It is suggested that the ladybirds play the important role of potential biological control in cotton agroecosystems.