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病虫害是破坏森林资源、影响造林绿化的重要因素之一,也是当前林业生产上比较突出的一个问题。据统计,在我国危害林木的病虫害有2,000多种,其中危害较大的有100多种。全国每年发生森林病虫害6-7千万亩,相当于全国每年造林的总面积。而防治面积一般只占发生面积的40％左右。病虫害造成的损失很大,据典型调查推算,全国每年仅因松毛虫为害而损失的林木生长量就有500多万立方米。广西梧州地区1975年由于松毛虫危害,松脂产量
Pests and diseases are one of the important factors that destroy forest resources and affect afforestation. They are also a prominent issue in forestry production. According to statistics, there are over 2,000 species of pests and diseases that endangered trees in our country, of which more than 100 are harmful. Every year, 6-7 million mu of forest pests and diseases occur in the country, equivalent to the total annual afforestation area in the country. The control area is generally only about 40% of the area. Pests and diseases cause great losses. According to the typical investigation and calculation, there are over 5 million cubic meters of tree growth loss each year due to damage caused by the pine caterpillars in the whole country. Guangxi Wuzhou area due to the damage of pine caterpillars in 1975, rosin production