论文部分内容阅读
农业科学家历来认为,是疾病和寄生菌以及气候等因素制约了虫口的增加。但最新发现树木可利用体内多种致命的化学物质来对付害虫,使树叶变得难以为昆虫所消化,并导致昆虫死亡。还能借空气传播某些化学物质,飘到邻近的树木上,使未受侵袭的树体内增加某些化学物质的含量,免受昆虫危害。一位科学家测定了被天幕毛虫取食的柳树的树叶,发现其含毒量增加很快,11.5天后毛虫就厌食这种树叶了。试验也已确证杨树、糖槭和红橡树
Agricultural scientists have always believed that diseases and parasites and climate and other factors restrict the population increase. But the latest discovery is that trees can use the body’s many deadly chemicals to deal with pests, making it harder for insects to digest leaves and causing insects to die. But also by air to spread certain chemicals, floated to the adjacent trees, so that no invasion of the tree to increase the content of certain chemicals from insects. A scientist measured the leaves of the willow tree fed by the celestial beetle and found that its toxic content increased rapidly and the caterpillar fed on the leaves 11.5 days later. Experiments have also confirmed poplar, sugar maple and red oak