英语听力文摘 English Digest 566、小虫防冻秘招！

 　　Bug¹ Antifreeze

 

　　Ever seen a cricket wearing a parka? Probably not, but you might have wondered how insects make it through the winter! After all, they’re cold-blooded, so their body temperature is pretty close to the temperature around them! Why don’t bugs² turn into popsicles?

 

　　Well, some do, of course. In a lot of insect species, only one stage is adapted to live through winter cold. For example, in some species, only those in the pupa stage, wrapped in insulated cocoons³, can stay warm enough to survive. Other bugs, like mosquitoes and grasshoppers⁴, don’t survive the winter themselves, but they lay their eggs in deep water or soil that won’t freeze hard. As long as their environment doesn’t freeze, the eggs will hatch in the spring.

 

　　Some adult insects and spiders actually do live through the winter, either by burying themselves deep in the ground, where the temperature is more moderate than the air temperature, or, of course, by moving into warm buildings!

 

　　Most bugs survive the winter’s cold by undergoing diapause, or insect hibernation⁵. No one knows whether bugs in diapause actually sleep, but most are totally inactive. Like animal hibernation, diapause drastically lowers a bug’s metabolism⁶, allowing it to survive all winter on its stored-up body fat.

 

　　Many diapausing bugs can survive even if their body temperatures drop below freezing. How? By making their own antifreeze! In diapause, insects’ bodies produce different types of alcohol. The alcohol in the bug’s system lowers the freezing point of its body fluids. This natural antifreeze lets many insects survive winter’s below-freezing temperatures, and wake up to make even more bugs next spring!

 

 

　　小虫防冻秘招！

 

　　你见过蟋蟀穿皮大衣吗？应该没有吧，但你或许想知道昆虫们是怎样度过冬天的。毕竟它们都是冷血动物，那它们的体温应该和周围环境差不多。可为什么昆虫们没有冻成冰棍呢？

 

　　当然啦，有一些昆虫会冻成冰棍。对于很多昆虫来说，它们只有处于某个特定的阶段才能活过寒冷的冬天。比如说，有些昆虫只有处于蛹期，被隔热的茧包裹起来时 才能维持足够的热量以存活。而另一些昆虫，比如蚊子和草蜢，它们本身无法在冬天里存活，但它们会把卵产在深水处及泥土中，而这些地方并不会完全冻住。只要 所处的环境不结冰，这些虫卵就能在春天孵化。

 

　　一些成虫，还有蜘蛛则依靠自身便能在冬天存活。它们要么将自己深埋在地底，因为那里的温度可比空气中温和得多。要么搬到到暖和的建筑当中居住。

 

　　大多数昆虫通过滞育，即虫类冬眠，来度过寒冬。没人知道滞育中的昆虫是否真的熟睡，但大多数昆虫处于完全不动的状态。就像动物冬眠一样，滞育能大幅减缓昆虫的新陈代谢，这样一来昆虫们便能凭借自身体内储存的脂肪度过整个冬天。

 

　　许多滞育中的昆虫即使体温降至冰点以下依然能够存活。这是怎么做到的？因为这些昆虫能自己生产“防冻剂”。当处于滞育当中时，这些昆虫体内会产生多种不同 的乙醇。这些乙醇使得昆虫体液的冰点降低。这种天然的防冻剂使得许多昆虫在气温低于冰点的冬天得以存活。当它们于春天醒来时，甚至能繁殖出更多的幼虫。

1 bug   

n.虫子；故障；窃听器；vt.纠缠；装窃听器

参考例句：

• There is a bug in the system.系统出了故障。
• The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。

2 bugs   

adj.疯狂的，发疯的n.窃听器( bug的名词复数 )；病菌；虫子；[计算机]（制作软件程序所产生的意料不到的）错误

参考例句：

• All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
• The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》

3 cocoons   

n.茧，蚕茧( cocoon的名词复数 )v.茧，蚕茧( cocoon的第三人称单数 )

参考例句：

• The silkworms have gone into the bushes to spin their cocoons. 蚕上山了。 来自《现代汉英综合大词典》
• In two more days the " little darlings" would spin their cocoons. 再得两天，“宝宝”可以上山。 来自汉英文学 - 春蚕

4 grasshoppers   

n.蚱蜢( grasshopper的名词复数 )；蝗虫；蚂蚱；（孩子）矮小的

参考例句：

• Grasshoppers die in fall. 蚱蜢在秋天死去。 来自《简明英汉词典》
• There are usually a lot of grasshoppers in the rice fields. 稻田里通常有许多蚱蜢。 来自辞典例句

5 hibernation   

n.冬眠

参考例句：

• Bears wake up in the spring after a winter of hibernation.熊经过一个冬天的冬眠后在春季苏醒。
• The tortoise spends the winter months in hibernation.乌龟在冬眠中度过寒冬季节。

6 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。