我国地域辽阔,自然条件多样,林木种类丰富,为害林木的病虫种类也十分繁多。根据全国森林病虫害普查资料统计,为害森林的病虫有8000多种,在全国范围内大量发生的有200多种,经常造成灾害的有100多种。1980年以来,全国每年森林病虫害的发生面积都在1亿亩以上。每年因森林病虫危害,减少的林木生长量约1500万立方米,造成的经济损失约20亿元,大 China has a vast territory with diverse natural conditions and rich forest types. The pest species that damage trees are also very diverse. According to the statistics of the National Forest Disease and Pest Survey, over 8,000 pests and diseases have been harmed in forests, over 200 occurred in large numbers in the country and more than 100 kinds of disasters have often been caused. Since 1980, the annual area of ​​forest pests and diseases in the country has been above 100 million mu. Each year due to forest pests and diseases, reduced forest growth of about 15 million cubic meters, resulting in economic losses of about 2 billion yuan, large