Cicadas: The dormant army beneath your feet - Rose Eveleth

腳下的休眠大軍：蟬 - Rose Eveleth

譯者: Shelly Wang 審譯者: wai ki ng

If you live on the east coast of the United States,

如果你住在美國東岸

用你過去十七年時間

you've spent the last 17 years of your life

walking, eating and sleeping

走路

吃東西

和睡覺

above a dormant army of insects.

在休眠的昆蟲大軍之上

These are the cicadas.

這些昆蟲就是蟬

Every 17 years,

每十七年時間

數十億的蟬，從地表出現

billions of them emerge from the ground to do three things:

來做三件事

脫皮

molt, mate and die.

交配

及死亡

There are 15 different broods of cicadas out there,

當牠們從地表出現時

grouped by when they'll emerge from the ground.

被歸類為十五窩不同的蟬

Some of these broods are on a 13-year cycle,

有些蟬窩的週期為十三年

others are on a 17-year clock.

其它則為十七年

Either way, the cicadas live underground for most of their lives,

不論何種形式，這些蟬大部分時間

都住在地底下

feeding on the juices of plant roots.

食用植物根部的液體

When it's time to emerge,

當該露面的時候

the adults begin to burrow their way out of the ground

成蟬就開始挖掘

離開地底的通道

直到地面

and up to the surface,

牠們只會待上幾個禮拜

where they'll live for just a few weeks.

而這段期間裡

During these weeks, though,

everybody will know the cicadas have arrived.

每個人都知道蟬已到來

There will be billions of them.

其數量高達數十億

And they're loud.

且聲響驚人

Male cicadas band together to call for female mates,

雄蟬會一起行動

邀請雌蟬

and their collective chorus can reach up to 100 decibels --

牠們集體行動的聲響

可達到近一百分貝

as loud as a chain saw.

和鏈鋸聲響一般

In fact, if you happen to be using a chain saw or a lawn mower,

事實上，如果你恰巧用上了鏈鋸

或割草機

male cicadas will flock to you,

成群公蟬就會飛向你

thinking that you're one of them.

認為你是牠們其中一員

如同自然定律

Now, like most things in nature,

the cicadas don't arrive without a posse.

牠們不會單獨行動

There are all sort of awesome and gross predators and parasites

因為有各種可怕又噁心的 掠食者及寄生蟲

that come along with the buzzing bugs.

伴隨牠們而來

Take the fungus Massospora for example.

以寄生菌 massospora 為例

這白色小菌種將自己隱藏

This little white fungus buries itself in the cicada's abdomen

在蟬的下腹中，侵蝕蟬肚

and eats the bug alive,

leaving behind its spores.

並將種子留下

當這些種子破裂時

When those spores rupture,

they burst out of the still-alive cicada,

牠們從仍活著的蟬腹中噴出

turning the bug into a flying saltshaker of death,

讓蟬的下腹如鹽巴揮灑 斷裂開而死亡

raining spores down upon its unsuspecting cicada neighbors.

並將種子灑落

在未加思索的隔壁蟬身上

雖然我們清楚的了解

But while we know pretty precisely

when the cicadas will arrive and fade away,

這些蟬會來到繼而死亡

we're still not totally certain of why.

但仍不完全確定為什麼

There are certain advantages

當然囉！讓整個物種同時出現

有一定的好處

to having your entire species emerge at once, of course.

The sheer number of cicadas coming out of the ground

數量龐大的蟬從地下而來

對掠食者而言聲勢浩大

is so overwhelming to predators, it is essentially guaranteed

實質上能保證的是

少數蟲子能存活、繁衍下一代

that a few bugs will survive and reproduce.

And since cicadas emerge every 13 or 17 years,

由於蟬每十三或十七年才出現

壽命比起很多牠們的掠食者都要長

longer than the lifespan of many of their predators,

the animals that eat them don't learn to depend on their availability.

捕食蟬的動物都

不會依賴牠們的存在

該想想為何是十三和十七年

But why 13 and 17 years,

instead of 16 or 18 or 12?

而不是十六

十八

或十二年

Well, that part no one really knows.

沒有人真正知道答案

It's possible the number just happened by chance,

這個數字很有可能只是碰巧發生了

或許蟬很喜愛質數

or, perhaps, cicadas really love prime numbers.

Eventually, the cicadas will mate and slowly die off,

牠們最後會交配並慢慢死亡

their call fading into the distance.

蟬鳴消逝於遠處

The eggs they lay will begin the cycle again,

牠們下的蛋會再度延續生命

their cicada babies burrowing into the earth, feeding on plant juice,

蟬寶寶在地表洞穴裡

以植物汁液為食

and waiting for their turn to darken the skies

等待牠們的時刻

來染黑天際

並賦予美妙的歌聲

and fill the air with their songs.

牠們用十七年時間準備

In 17 years, they'll be ready.

Will you?

你呢？