The bug that poops candy - George Zaidan

翻译人员: Harry SONG 校对人员: Meng Ren

This is Mabel.

这是 Mabel。

Mabel is an aphid, a small insect in the same order as cicadas, stink bugs,

Mabel 是一种蚜虫， 它是一种小型昆虫，

与蝉、椿象，和床虱 同属于半翅目。

and bed bugs.

All these bugs pierce their prey and suck out vital fluids.

它们都会刺破猎物 并吸取对其十分重要的汁液。

Aphids’ prey are plants.

蚜虫的猎物是植物。

And what aphids are after is buried within the plant,

它们吸食的物质存在于植物内部，

flowing in tubes made from single cells strung end-to-end.

这些物质在串联的 单细胞管道内来回流动。

These are called sieve tubes and together they form the plumbing system

这些管道被称为筛管， 它们共同构成了植物的管道系统，

for a plant’s most valuable resource: sap.

运输植物中最重要的资源：树液。

Sap is mostly water and sugar.

树液主要包含水和糖分。

Some species’ sap has as much sugar per liter as a can of soda.

有些种类的树液每升的含糖量 堪比一罐可乐。

Photosynthesis is constantly producing sugar.

光合作用会一直产生糖分。

You can think of it as a chemical “pump” which generates incredibly high pressure—

你可以把它看成一个化学“泵”， 会产生难以置信的高压——

up to 9 times that of a car tire— in the sieve tubes.

筛管中的压力最高可达 汽车胎压的 9 倍。

To feed, Mabel uses her stylet, which is a long, flexible needle.

Mabel 用它长长的、柔韧的 针管状口器来进食。

She slowly worms it into the tissue, between the plant’s cells,

它慢慢地将口器探进 植物细胞间的组织中去，

until she pierces one of those sieve tubes.

直到它刺穿一个筛管。

Because the sap is under so much pressure,

因为树液有很高的液压，

Mabel doesn’t even have to suck it out of the plant.

Mabel 甚至不需要费劲地吮吸树液。

She just opens a valve in her head and lets the pressure push the sap

它只需要打开头部的阀门， 然后液压会把树液

through her digestive system.

推入消化系统。

We’ll come back to what comes out of her butt, but for now,

我们待会儿再说它从屁股里 排出了什么，但是现在，

you should know that plants don’t want to be punctured and sipped.

你应该知道植物并不想被刺破 然后被吸食树液。

So they try to defend themselves.

所以它们会尝试保护自己。

One defense is the sap itself.

一种保护方式是利用树液本身。

To see how that works, let’s hypothetically hook up

要想了解其工作原理， 我们先假设性地让

some other insect’s digestive tract to a steady stream of sap.

树液稳定地流过 别的昆虫的消化道。

When that sap touches the insect’s cells, its high sugar content

当树液接触到昆虫的细胞时， 它的高糖成分

encourages the water in the cells to come out by osmosis…

会促使水分通过渗透作用 从细胞中流失......

exactly like salt encourages water to come out of a slug.

就像盐促使水分从蛞蝓中流失一样。

The more sap that passes through the insect, the more water it loses.

越多的树液流过昆虫的身体， 昆虫就会损失越多的水分。

Eventually, it shrivels up and dies.

最终，它会脱水而死。

Mabel’s gut, however, is packed with an enzyme called sucrase,

然而，Mabel 的肠子里 充满了蔗糖酶。

which takes two molecules of sucrose and converts them into one molecule

它会把两个蔗糖分子 转化为一个果糖分子

of fructose and one of… this three-unit sugar.

和一个三分子糖。

Mabel burns the fructose for energy, leaving the three-unit-sugar behind.

Mabel 把果糖作为能量消耗掉， 留下这个三分子糖。

Now, how does that help her?

那么，这是怎么帮助蚜虫的呢？

The more molecules of sugar that are dissolved in the sap,

越多的糖分子溶解在树液中，

the more water it can suck out of Mabel’s cells.

越多的水分就会 从 Mabel 的细胞中被吸出。

By reducing the number of molecules of sugar in the sap,

通过减少树液中的糖分子数，

Mabel reduces its ability to suck water out of her cells.

Mabel 就减轻了树液 吸取自身水分的能力。

Plant sap neutralized.

植物的树液失效了。

Now that means Mabel can feed for days, getting all the energy

这意味着 Mabel 可以连续进食多日，

she needs to reproduce.

得到繁殖所需要的所有能量。

Some aphid species have an incredible life cycle.

一些蚜虫有着难以置信的生命周期。

For example, the green peach aphid.

比如，桃蚜。

During the fall, males and females mate, and the females lay eggs.

秋天，雌雄交合，雌性产卵。

But in the spring, when the eggs hatch, all the nymphs that emerge are female.

到了春天，当卵被孵化， 所有生出来的若虫都是雌性。

When those females reach maturity, they don’t lay eggs.

当这些雌虫成熟后， 它们不会产卵，

Instead, they give birth to live young… that are clones of themselves…

而是直接克隆自己产生后代......

and already pregnant… with their own clones.

而这些克隆的后代也是 已经怀孕的.......怀着自己的克隆体。

So, these female aphids have two generations of baby aphid clones

所以，这些雌性蚜虫的体内

同时孕育着两代蚜虫克隆体。

forming inside themselves at the same time.

Scientists call this telescopic development.

科学家称之为重代。

That means that aphids can make more of themselves fast—

它意味着蚜虫能更快地繁殖后代——

there can be 20 generations within a single season—

一个季节可以有 20 代蚜虫出生——

and that means lots of aphid poop.

而这也意味着大量的蚜虫粪便。

Mabel can poop her entire body weight every two hours,

Mabel 每两个小时可以排出 相当于自身重量的粪便，

making her one of the most prolific poopers on the planet.

是这个星球上排便最多的生物之一。

Some aphid populations can produce hundreds of kilograms of poop per acre.

一些种群的排便量甚至高达 每英亩几百公斤。

Now, aphid poop is not like your poop.

不过，蚜虫的粪便可不像你的粪便。

Chemically, it’s not all that different from sap;

从化学组成上说， 它和树液也差不多。

it’s a clear and colorless sweet, syrupy liquid.

它是纯净的无色糖浆。

You might already know it by a different name: honeydew.

你可能已经知晓 它的另一个名字：蜜露。

Other species love honeydew.

有些生物很爱蜜露。

Some species of ants love it so much they sort of

一些蚂蚁是如此地喜爱蜜露，

herd and defend entire aphid colonies.

它们甚至会在某种程度上 聚集并捍卫整个蚜虫群。

In return, the ants get a steady supply of sweet honeydew,

作为回报，蚂蚁得到了 稳定的蜜露供应，

which they can drink directly from the aphids’ butts.

它们可以直接从蚜虫屁股里喝蜜露。

Bottom’s up!

喝光！

Humans love honeydew, too.

人类也爱蜜露。

Several Native American tribes used to harvest it from tall reeds

一些美洲原始部落 从高高的芦苇上采集蜜露，

and make it into cake.

然后做成蛋糕。

And some species of bee make honey from honeydew,

一些种类的蜜蜂采集蜜露 来酿造蜂蜜，

which humans then harvest and eat.

然后人类采集蜂蜜并吃掉。

So plants make the sap, which is eaten and pooped out by aphids,

所以植物产生树液， 蚜虫吸食树液，排出蜜露，

regurgitated by bees, harvested by humans,

蜜蜂采集蜜露，酿成蜂蜜 人类采集蜂蜜，

and dolloped into a cup of Earl Grey tea.

挖出一勺，调入了一杯伯爵茶。