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近三年来,库都尔林业局和乌尔其汗林业局部分白桦次生林中白桦尺蠖处于猖獗发展、漫延的趋势。1981年在库都尔林业局育林经营所,有局部小团块状发生;1982年乌尔其汗和库都尔林业局白桦叶被吃光的面积分别达到两千亩和六万亩;1983年库都尔林业局又扩大到15万亩。树木被害后,高生长降低30～70％;被害严重的林分,枝条干枯,呈现一片红褐色,如同火烧一般,严重地威协着白桦的生长。为对该虫进行预测、预报和防治,林管局森防站和库都尔林业局森防站联合织成了观测组,对该虫的生物学特性进行了初步观察和研究。现将结果整理如下:
In the past three years, the birch scale in the secondary birch secondary forests of the Kuduer Forestry Bureau and the Wuerqihan Forestry Bureau has been in a trend of rampant development and prolongation. In 1981, there was some small lumps in the forest management office of Kuduer Forestry Bureau. In 1982, the areas of the birch leaves eaten by the Urqin Khan and Kudu Er Forestry Bureau reached respectively two thousand and sixty thousand mu. 1983 Year Kudu Forestry Bureau has expanded to 150,000 mu. After the trees are harmed, the height growth is reduced by 30-70%. The severely damaged branches and branches are withered and reddish brown, showing a red-brown color. In order to predict, forecast and control the pest, the forest defense station and the Forest Park Forest Bureau of Forest were jointly organized into observation group, the biological characteristics of the insect were initially observed and studied. The results are now organized as follows: