Name: 糖果拉屎的蟲子--喬治-扎伊丹。 (The bug that poops candy - George Zaidan)
Uploaded: 2021-01-14T10:51:29.000Z
Duration: 4 min 47 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。學這些英文用法：TED-Ed

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

梅柏爾是蚜蟲，是和蟬、臭蟲、 床蝨同一目的小蟲子。

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

這類小蟲會刺穿牠們的獵物，吸出重要的液體。

And what aphids are after is buried within the plant, flowing in tubes made from single cells strung end-to-end.

蚜蟲的目標就埋藏在植物內部，在單一細胞連結而成的管道中流動。

These are called sieve tubes and together they form the plumbing system for a plant's most valuable resource: sap.

這些管道叫做篩管， 合起來便形成了管道系統， 運送植物最有價值的資源：液汁。

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

有些物種的液汁每公升含糖量等同於一罐汽水。

Photosynthesis is constantly producing sugar.

You can think of it as a chemical “pump” which generates incredibly high pressure — up to 9 times that of a car tire —  in the sieve tubes.

可以把它想像成化學「幫浦」， 它會在篩管中產生出—非常高的壓力—高達汽車胎壓的九倍。

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

梅柏爾用牠又長又有彈性的針狀口器來進食。

She slowly worms it into the tissue, between the plant's cells, until she pierces one of those sieve tubes.

牠緩慢地將口器鑽入組織中，穿過植物的細胞之間，直到刺入其中一條篩管。

Because the sap is under so much pressure, Mabel doesn't even have to suck it out of the plant.

因為液汁受到的壓力很大，梅柏爾甚至不需要將它吸出植物。

She just opens a valve in her head and lets the pressure push the sap through her digestive system.

牠只要打開牠頭部內的瓣膜，讓壓力將液汁打進牠的消化系統中。

We'll come back to what comes out of her butt, but for now, you should know that plants don't want to be punctured and sipped.

我們等下再談牠的屁股會排出什麼，但現在你應該知道植物並不喜歡被穿刺和啜飲。

其中一種防禦措施是液汁本身。

To see how that works, let's hypothetically hook up some other insect's digestive tract to a steady stream of sap.

為了說明它如何運作，那我們就假設性地將其他昆蟲的消化道連接上穩定的液汁供應流。

Now, when that sap touches the insect's cells, its high sugar content encourages the water in the cells to come out by osmosis, exactly like salt encourages water to come out of a slug.

當液汁接觸到昆蟲的細胞，有很高的糖含量的液汁就會促使細胞中的水分經由滲透作用跑出來…… 就像是鹽巴會促使水分從蛞蝓體內逼出來一樣。

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

通過昆蟲體內的液汁越多，牠的水分就會流失地越多。

Mabel's gut, however, is packed with an enzyme called sucrase, which takes two molecules of sucrose and converts them into one molecule of fructose and one of this three-unit sugar.

然而，梅柏爾的腸子中滿是一種叫做蔗糖酶的酵素，它能將兩個蔗糖分子轉換成為一個果糖分子， 以及一個這種三單位的糖。

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

梅柏爾將果糖燃燒產生能量，不管那三單位的糖。

The more molecules of sugar that are dissolved in the sap, the more water it can suck out of Mabel's cells.

越多糖分子被液汁溶解，就會有越多水分被吸出梅柏爾的細胞。

By reducing the number of molecules of sugar in the sap, Mabel reduces its ability to suck water out of her cells.

透過減少液汁中糖的分子數，梅伯爾就能降低它將水分從牠的細胞中吸出的能力。

Now that means Mabel can feed for days, getting all the energy she needs to reproduce.

那就表示，梅伯爾可以進食數天，取得牠繁殖所必要的所有能量。

Some aphid species have an incredible life cycle.

有些蚜蟲物種具有很不可思議的生命循環。

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

雄蟲和雌蟲會在秋天交配，由雌蟲產卵。

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

但在春天，當卵孵化時，所有的蛹幼都是雌的。

And when those females reach maturity, they don't lay eggs.

那些雌蟲長大成熟後並不會產卵。

Instead, they give birth to live young that are clones of themselves and already pregnant with their own clones.

反之，牠們會直接生出活的幼蟲…… 是牠們自己的複製品…… 且是已懷有身孕的複製品。

So, these female aphids have two generations of baby aphid clones forming inside themselves at the same time.

所以，這些雌蚜蟲有兩個世代的蚜蟲寶寶複製品同時在牠們體內成形。

Scientists call this telescopic development.

That means that aphids can make more of themselves fast — there can be 20 generations within a single season — and that means lots of aphid poop.

那就表示，蚜蟲可以很快速地複製自己，單一季就可以產生出 二十個世代，也表示會有大量的蚜蟲排泄物。

Mabel can poop her entire body weight every two hours, making her one of the most prolific poopers on the planet.

每兩小時，梅柏爾就會排出 和牠體重相等的排泄物，讓牠成為地球上 最會排泄的生物之一。

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

有些蚜蟲群可以製造出每英畝數百公斤的排泄物。

蚜蟲的排泄物和你的排泄物不同。

Chemically, it's not all that different from sap; it's a clear and colorless sweet, syrupy liquid.

化學上，它和液汁 沒有太大的不同；它是種清澈、無色、 有甜味、糖漿狀的液體。

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

你可能聽過它的另一個名字：甘露。

Some species of ants love it so much they sort of herd and defend entire aphid colonies.

有幾種螞蟻愛甘露愛到會聚集起來，保衛整群蚜蟲。

In return, the ants get a steady supply of sweet honeydew, which they can drink directly from the aphids' butts.

這些螞蟻得到的回報就是 穩定的甜甘露供應， 牠們可以直接從蚜蟲的屁股飲用甘露。

Several Native American tribes used to harvest it from tall reeds and make it into cake.

以前一些美國原住民部落會從高蘆葦上採甘露，製成蛋糕。

And some species of bee make honey from honeydew, which humans then harvest and eat.

有幾種蜜蜂會用甘露來做蜂蜜，而人類會採集蜂蜜來食用。

So plants make the sap, which is eaten and pooped out by aphids, regurgitated by bees, harvested by humans, and dolloped into a cup of Earl Grey tea.

所以，植物會產生液汁，蚜蟲會吃它再排泄出來，再由蜜蜂反芻，由人類採集，再加到一杯格雷伯爵茶裡。