【英语时差8,16】植物怎样自我防卫（上）

（单词翻译）

Most animals prefer to eat them. They can’t hit back or run away. Yet plants dominate vast areas of Earth’s continents. How Can Plants Have So Many Natural Enemies And Yet Be So Successful? Of course, some plants have physical defenses such as thorns and spines¹. But ecologists are finding that many more plants use chemical weapons to defend themselves. Some plants make their own insect repellents and insect poisons — a simple but effective strategy. Other plants make chemicals that closely resemble insect hormones³. An insect larva feeding on such a plant may have its development disrupted. For example, an African plant called the bugleweed has been found to make an imitation insect hormone² that causes many insect larvae⁴ to grow two or three heads. The mouthparts of a multi-headed larva don’t work properly, so the larva starves to death.