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我场各种松树面积5万亩,其中黑油松面积近3万亩,今年约有2万亩不同程度遭受松毛虫危害,被害树木轻者影响生长,重者近于濒死,多年来采用化学药剂防治的结果,虽然消灭了一些害虫,但松毛虫天敌也基本被药杀光,既破坏了自然界生物制约的客观规律,也给松毛虫等害虫大量繁殖造成有利条件,故年年防治年年成灾,通过调查
My field a variety of pine area of 50000 acres, of which the black pine area of nearly 30000 acres, about 20000 acres of different degrees of suffering from pine caterpillars this year, the victims of light trees affect the growth, severe near dying, over the years to adopt The results of chemical control, although the elimination of some pests, but the natural enemies of pine caterpillars are basically kill the light, not only undermined the objective laws of biological control in nature, but also to pine caterpillars and other pests caused favorable conditions for large-scale reproduction, so the annual control year In the disaster, through the investigation