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落叶松毛虫(Dendrolimuslstperans Butler)周期性大发生,与大发生基地(虫源)林分某些条件有密切关系。这些条件是:①13.3ha以上大面积落叶松纯林;②林龄在15年以上,郁闭度大于0.7;③低山、丘陵中上部,漫岗顶部。 在松毛虫大发生增殖期,大发生基地面积仅占全林面积的7.1％,便于重点控制。所采取的措施是:进行间伐抚育,改善基地林分生境;人工助迁蜘蛛;采用化学防治,把松毛虫虫口控制到最低水平线上;搞好封山育林、混交造林,预防松毛虫大发生基地的形成。
Dendrolimus slperans Butler occurs periodically, which is closely related to some conditions of large-scale base (insect source) stands. These conditions are: ① 13.3ha large area of pure forest Larix; ② more than 15 years old, canopy density greater than 0.7; ③ low mountains, hills in the upper part of the top of Man Kong. In the occurrence of large-scale growth of pine caterpillars, large base area accounted for only 7.1% of the total forest area, easy to focus on control. Measures taken are: thinning and tending to improve the alpine habitat; artificial spider migration; the use of chemical control, the Moth caterpillar population control to the lowest level; do a good job of closing hillsides afforestation, mixed afforestation, prevention of pine caterpillars occurred base formation .