松毛虫、杨毒蛾、美国白蛾等都是我省的主要食叶害虫,每年发生500多万亩。多年来曾采用多种化学药剂进行防治,也存在不少问题,主要是不符合经济、有效、安全的原则。1985年,在过去应用灭幼脲Ⅲ号防治农林害虫的研究基础上,辽宁省林业厅将“应用灭幼脲Ⅲ号防治森林主要害虫开发试验研究列为科研课题。委托辽宁省森防站和东北林业大学共同主持,1985—1986年在朝阳、阜新等9市20个县(区),进行了应用灭幼脲Ⅲ号防治松毛虫、 Dendrolimus, Yang poison moth, the United States and other white moths are the main leaf-eating pests in our province, occurring more than 500 million mu each year. Over the years have used a variety of chemical agents for prevention and control, there are many problems, mainly does not meet the economic, effective and safe principles. In 1985, based on the previous research on the application of meflorazone III in the control of agricultural and forestry pests, Liaoning Provincial Forestry Department classified "the application of meflorazone III in the prevention and control of major pests in forests as a research topic. Northeast Forestry University co-chaired 1985-1986 in Chaoyang, Fuxin and other nine counties in 20 counties (districts), the application of mefenapat III control pine caterpillars,