【英语时差8,16】植物怎样自我防卫（上）

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.

1 spines   

n.脊柱( spine的名词复数 )；脊椎；（动植物的）刺；书脊

参考例句：

• Porcupines use their spines to protect themselves. 豪猪用身上的刺毛来自卫。
• The cactus has spines. 仙人掌有刺。 来自《现代英汉综合大词典》

2 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

3 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

4 larvae   

n.幼虫

参考例句：

• Larvae are parasitic on sheep.幼虫寄生在绵羊的身上。
• The larvae prey upon small aphids.这种幼虫以小蚜虫为食。