论文部分内容阅读
鞘蛾种群数量不可能无限制增长,其原因是多方面因素综合作用的结果。风、食物、天敌及鞘蛾的自身密度等对鞘蛾的数量增长都有明显的抑制作用。春风能使树冠上27%左右的鞘蛾幼虫落地;早霜、晚霜、松毛虫、叶蜂及落叶松早期落叶病等都能直接影响鞘蛾食物的质量和数量,进而间接地使鞘蛾种群密度降低。捕食鞘蛾的天敌主要有鸟类、蚂蚁和蜘蛛;寄生性天敌多属于金小蜂科(Pteromalidae)、姬小蜂科(Eulophidae)、姬蜂科(Ichneumonidae)及茧蜂科(Braconidae)等。由鞘蛾自身密度所引起的自我调节是促使种群进化发展的重要因素之一,但是,这种因素的作用只有在密度大的时候方能显现出来。
There is no chance that the number of coleoptile moths will increase indefinitely, due to the combination of many factors. The self-density of wind, food, natural enemies, and coleoptera had a significant inhibitory effect on the growth of Coleoptera. Spring breeze can cause about 27% of the tree crown larvae larvae to fall to the ground; early frost, night cream, pine caterpillars, leaf bee and early deciduous diseases such as larch can directly affect the quality and quantity of coleoptera food, which indirectly causes the moth population density reduce. Natural enemies of predatory shell moths are mainly birds, ants and spiders; parasitic natural enemies are mostly belong to the family Pteromalidae, Eupatoridae (Eulophidae), Ichneumonidae (Ichneumonidae) and Braconidae (Braconidae) and so on. The self-regulation caused by the density of the coleoptile itself is one of the important factors to promote the evolution of the population. However, the effect of this factor can only be revealed when the density is high.