Parasite tales: The jewel wasp's zombie slave - Carl Zimmer

寄生的故事：金小蜂的僵屍奴隸 - Carl Zimmer

Transcriber: Andrea McDonough Reviewer: Bedirhan Cinar

譯者: Jephian Lin 審譯者: Coco Shen

I would like to introduce you to my favorite parasite.

我要向你介紹我最喜歡的寄生生物。

There are millions that I could choose from

這世上有上百萬種寄生生物，

and this is it:

而我要講的就是牠：

it's called the jewel wasp.

牠叫做金小蜂。

You can find it in parts of Africa and Asia.

你可以在某些非洲及亞洲地區找到牠。

It's a little under an inch long,

牠身長比一英寸短一些，

and it is a beautiful looking parasite.

是一種美麗的寄生生物。

Now, you may be saying to yourself,

現在，你可能心裡會想：

"This is not a parasite.

「這不是寄生生物吧？

It's not a tapeworm,

牠不是絛蟲、

it's not a virus,

how could a wasp be a parasite?"

也不是病毒，

胡蜂怎麼會是寄生蟲呢？」

You are probably thinking about regular wasps,

你可能想的是一般的胡蜂，

you know, the ones that build paper nests as their house.

就是那些築巢為家的生物。

Well, the thing is that the jewel wasp

重點在於，這金小蜂

makes its house inside a living cockroach.

會把活體蟑螂的身體 當作牠的家。

Here's how it happens.

過程是這樣的。

A jewel wasp is flying around, looking for a cockroach.

一隻金小蜂在四處亂飛， 在找尋蟑螂。

When it sees one, it lands and bites on its wing.

當牠找到的時候， 牠會降落在蟑螂身上然後咬牠的翅膀。

So, I'll be the cockroach.

所以，當作我是蟑螂。

Be-wha! Bewha!

噢！噢！

And the cockroach starts shaking it off,

然後蟑螂會想要把牠搖下來，像是：

"Get away from me!"

「不要碰我！」

The wasp very quickly starts stinging the cockroach.

於是金小蜂很快地螫了蟑螂一針。

All of a sudden, the cockroach can't move,

忽然之間

for about a minute.

蟑螂大約有一分鐘都不能動。

And then it recovers

接著牠復原了，

and stands up.

然後站起來。

It could run away now,

牠現在可以逃走，

but it doesn't.

但是牠沒有這麼做。

It just doesn't want to.

牠就是不想走。

It just stays there.

牠只是停在那。

It's become a zombie slave.

變成一個僵屍奴隸。

Again, I'm not making this up.

強調一下，這不是我編造的。

The wasp goes off,

這隻金小蜂會離開，

it walks away and finds a hole

牠會先去找一個孔洞，

and digs it out, makes it into a burrow.

把它挖深，變成一個洞穴。

It walks back.

牠爬回來。

This can take up to half an hour.

這可以花上半小時。

The cockroach is still there.

但蟑螂還在那。

What do we do now?

接著呢？

The wasps grabs onto one of the antenna,

這金小蜂會抓著一根蟑螂的觸角，

bites down on it,

咬緊它，

of the cockroach,

咬緊它，

and pulls the cockroach.

然後拉著蟑螂。

And the cockroach says, "Alright,"

然後蟑螂會說「好啦」，

and walks like a dog on a leash.

然後像鍊條上的狗 那樣往前走。

The wasp takes it all the way down into the burrow.

金小蜂牽著牠一路走到洞穴裡去。

The cockroach says, "Nice place."

然後蟑螂說：「這地方不錯。」

The wasp takes care of some business

金小蜂處理一些事情以後，

and then goes and leaves the burrow

就離開這個洞穴

and seals it shut,

並把牠封起來，

leaving the cockroach entombed in darkness, still alive.

把那隻還活著的蟑螂關在黑暗之中，

The cockroach says, "Alright, I'll stay here if you want."

蟑螂會說：「好吧， 如果你希望這樣的話，我會待在這。」

Now, I mentioned that the cockroach took care,

而，我剛提到蟑螂會處理一些……

ah, the wasp took care of a little business

呃，金小蜂會處理一些小事，

before it left the burrow.

在離開之前。

The business was laying an egg

這件事就是產卵、

on the underside of the cockroach.

在蟑螂腹部產卵。

The egg hatches.

卵會孵化。

Out comes a wasp larva.

跑出金小蜂幼蟲。

It looks kind of like a maggot with big, nasty jaws.

牠看起來像是蛆， 長著又大又噁心的下顎。

It chews a hole into the cockroach

牠在蟑螂身上啃出一個洞，

and starts to feed from the outside.

然後從外面開始餵食。

It gets bigger, like you can see over here.

牠會漸漸長大，就像這裡你看到的這樣。

And then when it gets big enough,

接著當牠長到夠大的時候，

it decides to crawl into the hole,

牠會爬進那個洞，

into the cockroach.

爬進蟑螂內部。

So now it's inside the still-living cockroach

所以牠會待在活體蟑螂的內部，

and the cockroach doesn't mind much.

而蟑螂並不太在意。

This goes on for about a month.

這會持續大約一個月。

The larva grows and grows and grows,

幼蟲會不斷長大、不斷長大，

then makes a pupa, kind of like a cocoon.

然後變成蛹、有點像是蠶繭那樣。

Inside there it grows eyes,

在裡面它長出了眼睛、

it grows wings,

長出了翅膀、

it grows legs,

長出腳，

the cockroach is still alive, still waiting.

而蟑螂則還活著、 還在原地等待。

Finally the wasp is ready to leave,

最後金小蜂準備要離開了，

and that's when the cockroach finally dies

這才是蟑螂最後死掉的時候，

because the fullly-formed adult wasp

因為金小蜂的成蟲

crawls out of the cockroach's dying body.

會爬出蟑螂的將死亡的軀體。

The wasp shakes itself off,

金小蜂會把身體甩乾淨，

climbs out of the burrow,

然後爬出洞穴，

goes and finds another wasp to mate with

去找另一隻可以交配的對象，

to start this whole, crazy cycle again.

然後重新開始這一整個瘋狂的循環。

So, this is not science fiction,

這並不是科幻小說，

this happens every day, all over the world.

在這整個世界上天天發生。

And scientists are totally fascinated by this.

科學家對此非常迷戀。

They're just starting to figure out how all this happens.

他們正開始要了解這一切是怎麼發生的。

And, when you really start to look at the science of it,

而，當你真的開始去探索其科學意涵，

you start to kind of respect this very creepy wasp.

你會有點開始尊敬這隻 毛骨悚然的胡蜂。

You see, the thing is that when it attacks the cockroach,

你可以看到，關鍵在於 當牠攻擊蟑螂的時候，

it's not just stinging wildly,

牠並不是隨便找地方螫，

it delivers two precise stings.

而是用了兩次精準的毒針。

It knows this cockroach's nervous system

這是蟑螂的神經系統，

like you know the back of your hand.

我們對它瞭若指掌。

The first sting goes to that spot there,

第一根針會螫在那裡，

called the "walking rhythm generators,"

這地方叫作「行走節律產生器」 （walking rhythm generators），

and, as you can guess,

而你可以猜到，

those are the neurons that send signals

這些就是傳送訊號

to the legs to move.

讓腳走動的神經元。

It blocks the channels that the neurons use

它會堵住這些

to send these signals.

So the cockroach wants to go, it wants to run away,

神經元用來傳送訊息的神經通道。

所以蟑螂想要跑，牠想要逃跑，

but it can't because it can't move its legs.

但就是做不到， 因為牠的腳沒辦法移動。

And that lasted for about a minute.

這會持續大約一分鐘。

This is really sophisticated pharmacology.

這真的是很先進的藥學。

We actually use the same method,

事實上，我們也有用同樣的方法，

a drug called Ivermectin,

用一種叫做伊維菌素（lvermectin）的藥，

to cure river blindness,

來治療河盲症 （river blindness），

which is caused by a parasitic worm

這是由一種叫蟠尾絲蟲的生物

that gets into your eye.

跑到眼睛裡所造成的。

If you take Ivermectin, you paralyze the worm

如果使用伊維菌素治療，

using the same strategy.

你就可以用同樣的方法 癱瘓這隻蠕蟲。

Now, we discovered this in the 1970s,

我們在 1970 年代發現這藥物，

the wasp has been doing this for millions of years.

而金小蜂已經用它幾百萬年了。

Then comes the second sting.

接下來就是第二針。

Now the second sting actually hits two places along the way.

這第二針實際上攻擊了兩個地方。

And to try to imagine how this can happen,

試著想看看一下這怎麼發生的，

I want you to picture yourself with a friend

我想要你想像一下 你身旁有一個朋友，

who's got a very long, very, very scary looking needle.

他拿著看起來非常、非常可怕的針。

And your friend,

而你的朋友，

or at least you thought he was your friend,

嗯……至少你覺得他是你的朋友，

sticks it in your neck,

把針從你的頸部

goes into your skull,

一路插進你的頭顱內，

stops off at one part of your brain

在你大腦的一個地方停下來 （注射聲）

and injects some drugs,

然後注射一些藥劑，

then keeps going in your brain

接著繼續插進你腦部 （注射聲）

and injects some more.

再注射另一些。

These are two particular spots,

這就是那兩個特別的地方，

marked here, "SEG",

標記在這裡：「SEG」、

and you can see the tip of it in the brain, marked "Br".

還有你可以看到在大腦裡針的末稍， 標記為「Br」。

Now, we can do this, but it's really hard for us.

這個我們也做得到，但是非常難。

It's called stereotactic drug delivery.

這叫做立體定位藥物傳輸 （stereotactic drug delivery）。

You have to put a patient in a big metal frame

你必須把病人放在 一個大的金屬框架上

to hold them still,

來固定他，

you need CAT Scans to know where you're going,

你還須要斷層掃描 來了解現在的位置，

so you look at the picture and say,

所以你會看著影像 然後說：

"Are we going the right way?"

「我們的方向對嗎？」

The jewel wasp has sensors on its stinger

在金小蜂的針上有一個感應器，

and scientists think that it can actually feel its way

科學家們認為它可以感應它在

through the cockroach's brain until it gets

蟑螂大腦裡的位置，

to the exact, right place,

直到它找到那精準的位置，

and then penetrates an individual neuron

然後刺穿某一個神經元

and then delivers the goods.

最後注射毒素。

So, this is quite amazing stuff,

這是一件很神奇的事情，

and what seems to happen then

它的過程似乎是

is that the wasp is taking away the control

金小蜂奪走了

that the cockroach has over its own body.

蟑螂對自己的身體控制權。

It's taking away the cockroach's free will.

奪走了蟑螂的自由意志。

We didn't really appreciate that cockroaches

若不是金小蜂這麼做，

have free will until this wasp showed us.

我們實在不會相信蟑螂會有自由意志。

And, we have no idea how it's doing this,

而我們對這過程還是沒什麼想法，

we don't know yet what the venom has in it

我們還不知道那毒液裡有什麼、

and we don't know which circuits

也不知道它攻擊的是 蟑螂大腦裡的哪個神經迴路，

it's hitting in the cockroach's brain,

也不知道它攻擊的是 蟑螂大腦裡的哪個神經迴路，

and I think that's why this is,

而我想，這就是為什麼

most of all, my favorite parasite

這是全部裡面 我最喜歡的寄生生物了，

because we have so much left to learn from it.

因為在這之中 我們還有許多可以學習。

Thank you very much.

謝謝各位。