英语听力文摘 English Digest 381、毛虫自卫战（在线收听）

Y: I could have sworn that I heard a strange tapping sound in my house last night. It was faint but chilling. I think there must be a ghost in my house.

D: Do you happen to keep caterpillars, perhaps the hook-tip moth?

Y:Why? Yes, I do. I have several little creatures. But what does that have to do with that tapping noise I heard?

D:That noise probably came from your caterpillars, and it probably means one of them invaded another's territory.

Y:I didn't know caterpillars were territorial.

D:Well, it turns out some are. In fact, what’s odd is that the hook-tip moth’s territorial behavior is much like that of many vertebrates, not what you’d expect in an organism like a caterpillar. These caterpillars find themselves a good leaf, and then they construct a nest of silk to protect them while they feast. When another caterpillar intrudes upon the resident caterpillar’s territory, the resident caterpillar stops eating, retreats into its nest, and it makes tapping noises by dragging or striking its mandibles against the leaf.

Y:What does the intruder do?

D:Often the intruder makes the sound as well and may end up attacking the resident’s nest by biting through some of the silk strands. Caterpillars don’t make this noise anywhere but in the nest, and scientists say this behavior suggests that the rivals are sizing each other up. They also suggest that the sounds may function to attract the attention of predators, in which case the intruder would be rather defenseless.

Y: 我发誓昨天晚上在家里我听到了很奇怪的敲打声。那个声音微弱至极，但就是让人毛骨悚然。我家里是不是有鬼啊！

D: 该不会你正好养了毛虫，或是钩翅蛾吧？

Y: 啊？嗯，我有养。我养了很多小动物。但那跟我晚上听到的声音有什么关系呢？

D: 那个声音很可能就是你养的小毛虫发出的。很有可能是一只小虫闯进了另一只的领地。

Y: 我都不知道毛虫还有领地呢！

D: 呃，有的是这样的。事实上，奇怪的是，钩翅蛾的占地行为更像是脊椎动物，并不像是你所想像的蛾类的占地行为。这些毛虫为自己找到一片好叶子，然后用丝筑一个巢。在毛虫“用餐”的时候，这个巢就可以起到保护作用。当另一只毛虫闯入该毛虫的领地时，“原住民”会立即停下用餐，退回巢内，借助拖拽鄂骨或是用鄂骨敲击叶子发出敲击声，以此威胁入侵者。

Y: 那么，入侵者又会怎么做呢？

D: 通常情况下，入侵者同样也会制造出敲击声，到最后会咬掉“原住民”巢内的部分丝线。毛虫只会在巢内发出这样的声音。科学家指出，这是双方在衡量对方的实力。同时，还指出，这种声音还会吸引来食肉动物，在这样的情况下，入侵者在防御上就会处于明显的弱势。

Notes:  hook-tip moth   钩翅蛾