对吉林省西部三北防护林的主要蛀干害虫青杨天牛 (Saperdapopulnea)近 5年发生的初步情况进行了一系列调查和研究 ,结果显示 :杨树品系白林 2号在白城地区 ,白城 41和辽杂 2号在双辽地区以及白林 3号和引进的新品系 392 0在松原地区是抗青杨天牛的优良杨树品系 ;同时确定了 3年生、6年生和 1 2年生的小×黑青杨天牛的发生量差异极显著 ,6年生的青杨天牛发生最重 ,其次为 3年生 ,1 2年生危害较轻 ;青杨天牛在树冠的垂直分布上差异显著 ;树冠的上层受害最重 ,中层略轻 ,下层受害最轻 A series of investigations and researches on the initial occurrence of Saperdapopulnea, a major pest boring pest of Three-North Shelterbelt in the west of Jilin Province in the recent five years, were conducted. The results showed that the poplar strain, “Bai Lin 2” Miscellaneous 2 in Shuangliao area and the new breed of Bailin 3 392 0 in Songyuan area is an excellent poplar young Poplar trees; at the same time to determine the 3-year-old, 6-year-old and 12-year-old small black poplar The occurrence of 6-year-old Poplar was the highest, followed by 3-year-old, and the 12-year-old was less harmful. The vertical distribution of Populus canadensis was significantly different from that of the canopy. The upper canopy was hardest hit, the middle was slightly lighter, Lightest victims of the lower