落叶松毛虫核型多角体病毒研究初报

落叶松毛虫(Dendroljmus superans)核型多角体为不规则形或四角形,大小为1.21—2.33μm;病毒束含病毒粒子数为1或多个;病毒粒子大小为29.1—60.5nm×244.2—325.6nm。

兴安落叶松林龄与耐害性关系的研究

分析兴安落叶松林龄及落叶松林木与落叶松毛虫耐害性的关系，提出了以林木材积连年生长量损失的百分数作为度量林木耐害性的指标。通过灰色关联分析，得出了在一定年龄范围内（１５～４５ａ），兴安落叶松林木对落叶松毛虫的耐害性随林龄的增加而增强，并且这种作用在高失叶率下更明显的结论；同时也指出了造成这种情况的原因，即在这一年龄段兴安落叶松林木的材积连年生长量随林龄增加而迅速增高。落叶松林木年龄越大，抗落叶松毛虫干扰的能力越强。因此，林龄增大，防治指标应提高。

The effect of Dendrolimus superans breakout on growth of trees

The effect ofDendrolimus superans on growth of trees was investigated after the breakout in Shibazhan forest area in 1990. Stem analysis was conducted for determining the tree increment loss. The result showed that the current annual increment for extreme heavily damaged, heavily damaged, moderately damaged and lightly damaged stands is 14%, 39.8%, 64% and 82% of that of the control forest respectively.