60秒科学:Antennae Key to Butterfly Navigation

Antennae¹ Key to Butterfly Navigation
A study in the journal Science shows that monarch² butterflies' sun-related directional sensing is governed by antennae, not the brain. Cynthia Graber reports

Every year, millions of monarch butterflies fly thousands of miles to alight in one specific forest in Mexico. How do they know what direction to flutter? Scientists had thought that an insect GPS system in their brains steered³ them in the right direction.

Now, a new study published in the journal Science overturns that idea. Because sun-related directional sensing actually resides in the butterfly’s antennae, say scientists at the University of Massachusetts Medical School.

The researchers remembered a half-century old study that noted⁴ that if butterflies lost their antennae mid-flight, they became disoriented. So they put butterflies in a flight simulator and tried to convince them to fly south. Those with their antennae intact had no problem orienting and flying south. But those without their antennae just couldn’t do it. Next they painted some butterflies’ antennae black, blocking light sensing. Those insects couldn’t orient themselves. But when researchers covered antennae in clear paint, the butterflies could once again fly in the correct direction.

Butterfly antennae were already known to sense odor, wind, even sound. Now it seems that they’re also vital for getting lonely Lepidopterans back to Mexico to mingle—and make the next generation of monarchs⁵.

—Cynthia Graber
 

1 antennae   

n.天线；触角

参考例句：

• Sometimes a creature uses a pair of antennae to swim.有时某些动物使用其一对触须来游泳。
• Cuba's government said that Cubans found watching American television on clandestine antennae would face three years in jail.古巴政府说那些用秘密天线收看美国电视的古巴人将面临三年监禁。

2 monarch   

n.帝王，君主，最高统治者

参考例句：

• The monarch's role is purely ceremonial.君主纯粹是个礼仪职位。
• I think myself happier now than the greatest monarch upon earth.我觉得这个时候比世界上什么帝王都快乐。

3 steered   

v.驾驶( steer的过去式和过去分词 )；操纵；控制；引导

参考例句：

• He steered the boat into the harbour. 他把船开进港。
• The freighter steered out of Santiago Bay that evening. 那天晚上货轮驶出了圣地亚哥湾。 来自《简明英汉词典》

4 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

5 monarchs   

君主，帝王( monarch的名词复数 )

参考例句：

• Monarchs ruled England for centuries. 世袭君主统治英格兰有许多世纪。
• Serving six monarchs of his native Great Britain, he has served all men's freedom and dignity. 他在大不列颠本国为六位君王服务，也为全人类的自由和尊严服务。 来自演讲部分