为了减少化学农药给农业系统带来不良影响,人们试用植物农药来干扰害虫的取食行为和生长发育,并把它称为第四代农药。解放后,我国有一段时间,曾利用苦楝树的果、叶、根、皮的浸出液来防治农作物害虫,后因杀虫效果差而中断。六十年代中期,英、美、西德、印度、菲律宾等国相继对苦楝树核、粉抽提物及其它活性物质的生物放应和杀虫机理开展了 In order to reduce the negative impact of chemical pesticides on agricultural systems, plant pesticides have been tried to interfere with pest feeding and growth and to call it the fourth generation of pesticides. After the liberation, our country for some time, had used the neem tree fruit, leaves, roots, skin leachate to control crop pests, insecticidal effect after the poor and interrupted. In the mid-1960s, the United States, the United States, West Germany, India, the Philippines and other countries have been on the neem tree nuclear, powder extract and other bioactive substances and biological insecticidal mechanism carried out