英語(yǔ)聽(tīng)力文摘 植物大戰(zhàn)毛毛蟲(chóng)
植物大戰(zhàn)毛毛蟲(chóng)
If you have kids, you’ve probably read the children's book: The Very Hungry Caterpillar, see, at least five thousand times. If you haven’t had the pleasure, here’s a brief plot summary. A caterpillarhatches from a small, white egg. Extremely hungry, the caterpillar proceeds to eat through several pieces of fruit, an assortment of junk food, and finally, to clear the palate, a nice green leaf. At the risk of ruining the ending, on the final page the caterpillar turns into a beautiful butterfly.
Good plot, great characterization, enticing illustrations. But it leaves out the most exciting part–plant-insect warfare. In the real world, some caterpillars and plants engage in a deadly struggle for survival. We’re talking full-scale battle, involving chemical weapons no less.
Scientists have known for some time that many plants protect themselves from insect attacks by producing toxins that either ward off or kill insects when they attempt to have the plant for lunch. What scientists have only recently discovered, however, is that the common caterpillar is not without its own arsenal of chemical agents. According to recent studies, a caterpillar can sense when a plant is about to unleash its chemical weapons and counter by producing anti-toxins to neutralize the plant’s attack.
So far, caterpillars seem to have the upper hand. Although different plants produce a wide variety of toxins, many ultimately rely on two main chemicals. Since caterpillars have evolved to neutralize these chemicals, they are able to infest over one-hundred toxin-producing plant species across the United States.
如果你身為人父或身為人母，那你對(duì)兒童讀物《肚子好餓的毛毛蟲(chóng)》一定不會(huì)陌生。如果你還沒(méi)讀過(guò)這本書，不要緊，故事講述了這樣一個(gè)故事：一條毛毛蟲(chóng)從一個(gè)又小又白的卵殼里爬出，饑腸轆轆的毛毛蟲(chóng)狼吞虎咽地咽下不少水果和垃圾食物，最后，還啃下一片可愛(ài)的綠樹(shù)葉來(lái)清清腸道。故事的結(jié)尾很美滿，毛毛蟲(chóng)破繭成蝶!
故事情節(jié)很好，文筆細(xì)膩，插圖精美。但是遺漏了最精彩的環(huán)節(jié)：植物大戰(zhàn)毛毛蟲(chóng)。在現(xiàn)實(shí)中，毛毛蟲(chóng)和植物為求生存而殊死搏斗，而全面戰(zhàn)爭(zhēng)肯定少不了化學(xué)武器。下面我們就來(lái)談?wù)劙?
科學(xué)家很早就發(fā)現(xiàn)，一些植物釋放或分泌有毒物質(zhì)，擊退視植物為午餐的昆蟲(chóng)，以求自保;而這些有毒物質(zhì)有時(shí)是致命的。直到最近，科學(xué)家才發(fā)現(xiàn)原來(lái)毛毛蟲(chóng)普遍也有自己的“化學(xué)兵工廠”。據(jù)最新研究表明，毛毛蟲(chóng)可以感應(yīng)植物何時(shí)準(zhǔn)備釋放“化學(xué)武器”，而分泌有毒物質(zhì)抗體，與植物抗衡。
目前，毛毛蟲(chóng)稍占上風(fēng)。雖然，千差萬(wàn)別的植物釋放的有毒物質(zhì)品種繁多，但是主要?dú)w結(jié)于兩大類。而毛毛蟲(chóng)進(jìn)化得足以抵御這些化學(xué)物質(zhì)，足以自如應(yīng)對(duì)全美上百種有毒植物。
