Why are cockroaches so hard to kill? - Ameya Gondhalekar

譯者: Leigh Yapp 審譯者: Bruce Sung

In the Egyptian Book of the Dead, there’s a banishment spell that declares,

在古埃及的《亡靈書》中 有一段驅逐咒是這麼說的

“Be far from me, O vile cockroach.”

「卑鄙的蟑螂啊！離我遠一點。」

More than 3,000 years later, we’re still trying to oust these insects.

三千多年過後，我們仍舊 嘗試著要趕走這些昆蟲

But from poison traps to hastily brandished slippers,

只是，從毒餌陷阱到 揮舞中的拖鞋

cockroaches seem to weather just about everything we throw at them.

蟑螂似乎能夠經受起 我們對牠們做出的一切

So what makes cockroaches so hard to kill?

那麼，是什麼原因 讓蟑螂這麼難被殺死？

There are nearly 5,000 cockroach species.

世界上有將近五千種 蟑螂的品種

99% of them live in a range of habitats where they play important ecological roles

99% 的品種在一系列的棲息地中 發揮了重要的生態作用

by recycling dead or decaying organic matter

牠們回收死亡或腐爛的有機物

and nourishing other animals.

滋養了其他的動物

But a couple dozen species adapted to live in close association with humans.

但有幾十個物種已經適應了 與人類密切相關的生活

German and American cockroaches are among the most common.

德國蟑螂和美國蟑螂就包含在 最常見的這幾個品種當中

And they owe their resilience to a combination

牠們的復原能力歸功於一個組合

of physical and chemical adaptations.

是關於物理上和化學上的適應性

When it comes to old-fashioned removal methods,

用過時的方法來防治蟑螂

they're troublingly tenacious.

牠們頑強對抗的程度可是令人擔憂

An American cockroach’s sensory hairs or structures pick up subtle air currents

美國蟑螂可以利用感覺毛或是 感覺結構去捕捉細微的氣流

and rapidly send signals to its central nervous system.

然後迅速發出訊號 給體內的中樞神經系統

The roach can then turn and sprint away within a few milliseconds.

蟑螂可以在幾毫秒內轉身 然後飛奔離開

And it’s among the fastest invertebrates ever recorded,

牠們是有紀錄以來 速度最快的無脊椎動物之一

reaching speeds of up to 50 body lengths per second.

移動速度高達 每秒五十倍體長的距離

This would be the human equivalent of running more than 300 kilometers per hour.

相當於人類每小時跑超過三百公里

And finding a hiding place is no problem.

牠們要找到藏身之處是易如反掌

With its flattened, flexible body,

牠們的身體又扁薄又靈活

an American cockroach can squeeze into spaces less than a quarter of its height.

一隻美國蟑螂可以擠進一個 不及其身高四分之一的空間裡

即使我們真的要打蟑螂，牠也能 承受自身重量九百倍的壓縮力

Even if we do land a hit, it can withstand compressive forces

of up to 900 times its own weight by distributing the impact along its body.

因為牠會把這股力量 分散到全身各處

And the cockroach’s toughness doesn’t end there.

蟑螂的韌性還不只如此

Cockroaches can eat a variety of organic matter,

蟑螂能吃各式各類的有機物

including hair, dead skin, adhesives, and paper.

包括頭髮、皮屑、黏著劑，以及紙張

This is made possible by an expansive set of digestive enzymes.

牠們能以這些東西為食，是因為 一組廣泛的消化酵素的關係

Cockroaches are able to thrive even in nutrient-poor environments.

蟑螂即便待在營養匱乏的環境中 一樣可以活得好好的

Roaches often eat decaying foods that are low in nitrogen—

蟑螂通常是吃腐爛的食物 其氮元素的含量很低

an essential component of DNA and proteins.

氮對於 DNA 和蛋白質來說 是不可或缺的元素

But they survive by storing nitrogen-containing wastes in their bodies

蟑螂藉著在體內儲存 含有氮的廢物來生存

and having a resident group of bacteria recycle the nitrogen

並且讓體內的常駐菌群

將氮回收轉化為有益的分子

into useful molecules for them.

Meanwhile, German cockroaches will eat their own poop, vomit,

德國蟑螂會吃下自己的大便和嘔吐物 還有那些死亡的，或垂死的同伴

and dead or dying colony members without hesitation.

一點兒都不會猶豫

An American cockroach will frolic in sewers,

美國蟑螂會在地下水道尋樂 大快朵頤排泄物

consuming excrement and toting microbes like Staphylococcus aureus and E.coli.

身上還攜帶著像是金黃色葡萄球菌 或是大腸桿菌的病原

But they’ll rarely suffer any consequences.

但牠們鮮少出現不良的後果

This is because they’re equipped with genes that provide immunity

這是因為他們有免疫能力的基因組

against numerous pathogens.

可以對抗多種病原體

These genes are often duplicated many times over.

這些基因組通常會被複製好幾次

So when infected, the cockroach’s immune system efficiently unleashes

所以當蟑螂受感染時

牠們的免疫系統就會釋放出 許多抗微生物的分子

many antimicrobial molecules.

Cockroaches also have a slew of defenses against pesticides.

蟑螂也有一連串可以 對抗殺蟲劑的防禦措施

When a non-resistant roach walks on a surface that’s been sprayed

例如，一隻無抗藥性的蟑螂走過一片

被噴灑了類除蟲菊精 殺蟲劑的表面時

with a pyrethroid insecticide, for example,

the results will likely be fatal.

可能會有致命的結果

Once absorbed, the chemical binds to sodium channel proteins,

一旦殺蟲劑被吸收，其化學物質 就會與鈉離子通道蛋白結合

which help propagate nerve impulses.

進而傳播神經衝動

The pyrethroid keeps the sodium channels open,

類除蟲菊精可以 讓鈉離子通道保持開通

so the nerves fire repeatedly.

所以神經會重複一直發射

And soon, the cockroach dies.

不用多久，蟑螂就會死了

But if a resistant roach is exposed to pyrethroids, it’ll be just fine.

但若是有抗藥性的蟑螂接觸到 類除蟲菊精，牠們會毫髮無傷

Genetic mutations have given them sodium channels

基因突變使得牠們有了 另外一種鈉離子通道

that the pyrethroids can’t bind to.

讓類除蟲菊精無法和通道蛋白結合

The cockroach also produces more detoxification enzymes,

牠們還產生了更多的解毒酵素

which render the pesticide harmless,

使得殺蟲劑對牠們不具作用

and the cockroach simply excretes it as a waste.

牠們只是把殺蟲劑 當成廢物一樣排出體外

Because German cockroaches reproduce especially quickly,

因為德國蟑螂繁衍的速度特別快

populations may evolve resistance to a new pesticide within months.

各群體可能在幾個月內 就會對新的殺蟲劑產生抗藥性

So far, they're already resistant to 43 different chemicals.

至今，牠們已經對四十三種 不同的化學物質產生抗藥性

But contrary to popular belief,

但，與大眾看法相反的是

cockroaches would probably not survive a nuclear apocalypse.

蟑螂可能無法在核災中倖存下來

Compared with other insects,

相較於其他昆蟲

cockroaches are only mildly tolerant to radiation.

蟑螂對核輻射的耐受性很低

They would die near the sites of nuclear explosions

牠們會死在核爆地點的周圍

and would still be severely compromised miles away.

並且在數英里之外 依然還會受到嚴重的損害

Moreover, disasters that threaten humanity

此外，威脅到人類的災難

also jeopardize the habitats and buffets we provide roaches.

也會危及到我們供給蟑螂的 棲息地和食物來源

Perhaps the only way to beat them is through our mutual destruction.

也許唯一能戰勝牠們的方法 是透過我們互相毀滅

Or maybe cockroaches would find even more surprising ways to thrive

又或是，蟑螂會自己找到 令人驚奇的活路

long after we’re gone.

就在人類消失了很長一段時間之後