论文部分内容阅读
七、自然限制因子 1.树木生理因子美国通过生命表的研究发现,受害松树的韧皮部细胞经反复为害而死亡是松干蚧数量下降的首要因子,其次,松树受害后流脂也会影响松干蚧的发育及数量。 2.天敌因子天敌因子是限制此虫发生的重要因子之一。世界各国松干蚧的天敌很多,其科、目几乎完全相同,但种类不一样。常见者有瓢虫、花蝽、益蛉、盲蛇蛉、瘿蚊、大赤螨、蜘蛛及蚂蚁等各种扑食性昆虫。在中国还发现二种细
Seven, the natural restriction factor 1. Tree physiological factors The United States through the life table study found that the injured pine phloem cells after repeated damage is the primary factor in the decline in the number of dry scales, followed by the flow of fat pine trees will affect the development and Quantity. 2. Natural enemy factor Natural enemy factor is to limit the occurrence of this insect one of the important factors. The natural enemies of many countries in the world are numerous, their families and subjects are almost identical, but the species is different. Common are ladybugs, stink bugs, benefits 蛉, blind snake 瘿, 瘿 mosquitoes, Dickies mites, spiders and ants and other insecticides and other prey. In China also found two kinds of fine