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落叶松毛虫〔Dendrolimus superans(Butler)〕在我市主要为害落叶松、黑松、红松。该害虫在我市是1964年发现的,当时,仅国营白泉林场六二八林班,有二百亩落叶松人工纯林发生为害。到1967年蔓延到全市九个国营林场,十几个林班发生,面积达一万五千亩。1968年全市被害面积扩大到五万七千亩,严重的是白泉林场连泉林班,有二百三十五亩八年生落叶松人工林,平均树高四米,有虫株率100%,单株最多的虫口密
Dendrolimus superans (Butler)] Larch, black pine and korean pine are mainly harmed in our city. The pest in our city was discovered in 1964, when only the state-owned Baizuolin forestry field June 28 forest classes, there are two hundred acres of Larch artificial pure forest damage. To 1967 spread to the city’s nine state-owned forest farms, a dozen forest classes occurred, an area of 15,000 acres. 1968, the city’s area of ?? victims expanded to 57,000 acres, the serious is the White Springs Linquanyuanlin classes, there are 235 acres of 8-year-old larch plantation, the average tree height of 4 meters, with worm strain rate of 100% Insect pests most dense