The bug that poops candy - George Zaidan
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0:07 - 0:09This is Mabel.
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0:09 - 0:15Mabel is an aphid, a small insect
in the same order as cicadas, stink bugs, -
0:15 - 0:17and bed bugs.
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0:17 - 0:21All these bugs pierce their prey
and suck out vital fluids. -
0:21 - 0:23Aphids’ prey are plants.
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0:23 - 0:26And what aphids are after
is buried within the plant, -
0:26 - 0:30flowing in tubes made from single cells
strung end-to-end. -
0:30 - 0:34These are called sieve tubes and together
they form the plumbing system -
0:34 - 0:38for a plant’s most valuable resource: sap.
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0:38 - 0:40Sap is mostly water and sugar.
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0:40 - 0:43Some species’ sap has as much sugar
per liter as a can of soda. -
0:43 - 0:46Photosynthesis is constantly
producing sugar. -
0:46 - 0:50You can think of it as a chemical “pump”
which generates incredibly high pressure— -
0:50 - 0:54up to 9 times that of a car tire—
in the sieve tubes. -
0:54 - 0:58To feed, Mabel uses her stylet,
which is a long, flexible needle. -
0:58 - 1:02She slowly worms it into the tissue,
between the plant’s cells, -
1:02 - 1:05until she pierces
one of those sieve tubes. -
1:05 - 1:08Because the sap
is under so much pressure, -
1:08 - 1:10Mabel doesn’t even have to suck it out
of the plant. -
1:10 - 1:15She just opens a valve in her head
and lets the pressure push the sap -
1:15 - 1:17through her digestive system.
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1:17 - 1:20We’ll come back to what comes out
of her butt, but for now, -
1:20 - 1:23you should know that plants don’t want
to be punctured and sipped. -
1:23 - 1:25So they try to defend themselves.
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1:25 - 1:27One defense is the sap itself.
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1:27 - 1:30To see how that works, let’s
hypothetically hook up -
1:30 - 1:35some other insect’s digestive tract
to a steady stream of sap. -
1:35 - 1:38When that sap touches the insect’s cells,
its high sugar content -
1:38 - 1:42encourages the water in the cells
to come out by osmosis… -
1:42 - 1:46exactly like salt encourages water
to come out of a slug. -
1:46 - 1:50The more sap that passes through
the insect, the more water it loses. -
1:50 - 1:53Eventually, it shrivels up and dies.
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1:53 - 1:56Mabel’s gut, however, is packed
with an enzyme called sucrase, -
1:56 - 2:00which takes two molecules of sucrose
and converts them into one molecule -
2:00 - 2:04of fructose and one of…
this three-unit sugar. -
2:04 - 2:09Mabel burns the fructose for energy,
leaving the three-unit-sugar behind. -
2:09 - 2:11Now, how does that help her?
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2:11 - 2:14The more molecules of sugar
that are dissolved in the sap, -
2:14 - 2:17the more water it can suck out
of Mabel’s cells. -
2:17 - 2:20By reducing the number of molecules
of sugar in the sap, -
2:20 - 2:23Mabel reduces its ability to suck water
out of her cells. -
2:23 - 2:25Plant sap neutralized.
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2:25 - 2:29Now that means Mabel can feed for days,
getting all the energy -
2:29 - 2:32she needs to reproduce.
-
2:32 - 2:35Some aphid species
have an incredible life cycle. -
2:35 - 2:37For example, the green peach aphid.
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2:37 - 2:41During the fall, males and females mate,
and the females lay eggs. -
2:41 - 2:47But in the spring, when the eggs hatch,
all the nymphs that emerge are female. -
2:47 - 2:51When those females reach maturity,
they don’t lay eggs. -
2:51 - 2:56Instead, they give birth to live young…
that are clones of themselves… -
2:56 - 3:01and already pregnant…
with their own clones. -
3:01 - 3:06So, these female aphids have
two generations of baby aphid clones -
3:06 - 3:09forming inside themselves
at the same time. -
3:09 - 3:12Scientists call this
telescopic development. -
3:12 - 3:15That means that aphids can make
more of themselves fast— -
3:15 - 3:18there can be 20 generations
within a single season— -
3:18 - 3:21and that means lots of aphid poop.
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3:21 - 3:25Mabel can poop her entire body weight
every two hours, -
3:25 - 3:28making her one of the most prolific
poopers on the planet. -
3:28 - 3:33Some aphid populations can produce
hundreds of kilograms of poop per acre. -
3:33 - 3:36Now, aphid poop is not like your poop.
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3:36 - 3:38Chemically, it’s not all that different
from sap; -
3:38 - 3:41it’s a clear and colorless sweet,
syrupy liquid. -
3:41 - 3:45You might already know it
by a different name: honeydew. -
3:45 - 3:47Other species love honeydew.
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3:47 - 3:49Some species of ants love it so much
they sort of -
3:49 - 3:53herd and defend entire aphid colonies.
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3:53 - 3:56In return, the ants get a steady supply
of sweet honeydew, -
3:56 - 3:59which they can drink directly
from the aphids’ butts. -
3:59 - 4:00Bottom’s up!
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4:00 - 4:02Humans love honeydew, too.
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4:02 - 4:05Several Native American tribes
used to harvest it from tall reeds -
4:05 - 4:06and make it into cake.
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4:06 - 4:09And some species of bee make honey
from honeydew, -
4:09 - 4:12which humans then harvest and eat.
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4:12 - 4:15So plants make the sap,
which is eaten and pooped out by aphids, -
4:15 - 4:18regurgitated by bees,
harvested by humans, -
4:18 - 4:21and dolloped into a cup of Earl Grey tea.
- Title:
- The bug that poops candy - George Zaidan
- Speaker:
- George Zaidan
- Description:
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View full lesson: https://ed.ted.com/lessons/the-bug-that-poops-candy-george-zaidan
Aphids can reproduce incredibly fast: they can make 20 new generations within a single season. And that means lots of poop. Some aphid populations can produce hundreds of kilograms of poop per acre— making them some of the most prolific poopers on the planet. We know this poop as the sweet, syrupy liquid called honeydew. George Zaidan explores the wonderfully weird life of an aphid.
Lesson by George Zaidan, directed by Hype CG.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 04:23
Elise Haadsma approved English subtitles for The bug that poops candy | ||
Elise Haadsma accepted English subtitles for The bug that poops candy | ||
lauren mcalpine edited English subtitles for The bug that poops candy |