应用薰蒸毒签防治杨树天牛须注意的几个问题近些年来，随着我国北方地区以杨树为主的平原绿化和农田防护林的迅速发展，杨树天牛的危害也日趋严重。当前，在许多地区的天牛防治工作中，应用薰蒸毒签已成为主要手段，由于毒签具有使用时期长（一年内春、夏、秋幼虫活动期都... In recent years, with poplar-dominated plains afforestation and rapid development of farmland shelterbelts in northern China, the harm of poplars is becoming more and more serious. At present, in many areas of Tian Bei prevention and control work, the application of defilement has become the main means of poisoning, because of the use of toxins have a long period of use (within a year of spring, summer and autumn larvae are active period ...