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近两年来,油松毛虫(Dendrolimus tabulaeformisTsai et Liu)在陕西黄龙山林区北寺山林杨猖獗发生。1964年,该场曾先后用烟雾、喷粉、人工扑打、束草诱杀等方法进行了全面防治。但虫口密度仍异常惊人。据1965年3月初调查,平均株虫口密度786条,最多株虫口2900条,最少的7条。看来有可能再度猖獗发生。为了加强防治,我们依据油松毛虫3月下旬开始上树取食的习性,于1965年初春在北寺山林场,利用毒环法,进行了500亩大面积防治的初步试验,效果良好,对害虫的发生起了很大抑制作用。现将试验结果报道如下,以供参考。
In the past two years, Dendrolimus tabulaeformis Tsai et Liu was found rampant in the North Temple of Huanglong Mountain in Shaanxi Province. In 1964, the field had conducted comprehensive prevention and treatment with such methods as smoke, dusting, artificial swatting and trailing sowing. However, the population density is still unusually alarming. According to a survey conducted in early March 1965, the average population density of insect pests was 786, with a maximum of 2900 insect pests and a minimum of 7 pests. It seems likely to happen again rampant. In order to strengthen prevention and control, we conducted a pilot study on large-scale prevention and control of 500 mu using the poison ring method in early spring 1965 in accordance with the habit of feeding the tree with the pine caterpillars beginning in late March. The occurrence of a great inhibition. The test results are reported below, for reference.