The Vine That ‘Loves’ Parasitic Wasps to Death

[♩INTRO] “The love vine” seems like a strange nickname
for a parasitic plant especially one that can be so demanding of
its hosts that they die. But it’s counterintuitive name isn’t what
makes it unique. Instead, it’s special because it’s the
only organism we know of that sucks the life out of plants and their insect parasites
simultaneously. Seems…kind of… straight out of a horror
movie. In nature, certain wasps, flies, and other
parasitic insects manipulate plants into producing galls, tumor-like growths full of tasty, nutritious
plant material. To do it, females lay their eggs on or in
the plant in question, along with a special chemical cocktail that triggers the
plant to start forming a gall. The size, shape, and content of the growths
is chemically controlled by the parasites, so they can force their host to
make perfect little nurseries. And the gall’s exterior is both tough and
loaded with noxious chemicals, so not many animals are able to break through
to the vulnerable larva inside. But Cassytha filiformis is no animal. It’s a vine. It’s so common in tropical environments
worldwide that people from many cultures have used it medicinally and mystically
for centuries. That’s actually where its common name “the
love vine” comes from its supposed utility is as an aphrodisiac. For a while, this vine was thought to prey
solely on other plants for physical support, water, and nutrients. Then, researchers saw something weird. In 2018, scientists studying gall-forming
wasps in Florida discovered love vines wrapped around nearly 60 of the galls of one
wasp species they’d collected. Nearly half of those galls contained dead,
mummified adult wasps, while only 2% of vine-less galls did. That strongly suggests that the vines steal
from the insects as well as the tree. Now, it does make sense that the vines would
feed on galls they’re basically juicy, starchy cancers. They’re perfect snack even without a protein-packed
larva inside. And unlike with most animal predators, the outer gall casing is no obstacle for the
love vine. It already steals from its host using haustoria, which are kind of like specialized roots. They can tunnel through thick bark to find
a tree’s juiciest tissues, so they have no trouble worming their way
through the tough shells of galls. But the fact that they also nom on the wasps
was a little more unusual. And once the team started looking, they found
the vine sucking the life from several other species of gall-forming parasites,
too. Through other observations, they even realized
the vines weren’t stumbling upon the galls by accident. But that’s not the weirdest part. The parasitized galls were also 35% larger. So either the vines selectively target large
galls… or they somehow make the galls they’re feeding
from grow. They could be tricking the insects into tricking
the trees into making bigger galls. As unlikely as that sounds, the fact that
the dead wasps inside vine-attacked galls were adults could actually
support the idea. If nothing else, that shows the vines take
their time to let the insects develop before sucking
them dry. So far, the love vine is the only parasite
we know of that attacks its hosts’ parasites in this way. But there are thousands of parasitic plants and tens of thousands of gall-forming insects. If it took this long to notice this vine’s
thirst for flesh, there could be dozens or even hundreds of parasitic plants just waiting
for their carnivory to be revealed. Thanks for watching this episode of SciShow! If you’d like to learn another bizarre fast
fact, you can watch our episode about this baller rat that kicks rattlesnakes in
the face! Or you can go to to subscribe. [♩OUTRO]

100 Replies to “The Vine That ‘Loves’ Parasitic Wasps to Death”

  1. Well, it took us long enough to work out that a lot of traditional herbivores will munch down on cadavers or baby birds if given the chance XD

  2. We should love them. I can imagine someone trying to engineer them to attack only the parasites, and then it all goes horribly…

  3. I read the title as "the vine that loves PLASTIC WRAPS" and only realized I was wrong when the video was over and I re-read the title 🤦🏻‍♂️

  4. Could you guys maybe make a video about the Gates foundation's reinvent-the-toilet-challenge winners? they seem so interesting and important and I would love to understand how they work 🙂

  5. sometimes I make things up for my stories and they seem too far-fetched.

    Then I hear about these things actually existing in nature and I resolve never to doubt myself again.

  6. "This vine's thirst for flesh" ok that legit made me curious: does insects (like the wasp) counts as "having flesh"? If there's a video about this or something similar already someone let me know

  7. Why do some people just not bruise unless there is severe trauma? For myself I havent had a bruise since the last time i had surgery and before that I had to get hit by a car to get a bruise.

  8. I can't imagine a less dignified way to die than getting eaten by a plant.

    Edit: well actually, there's autoerotic asphyxiation. But I can't think of 2.

  9. Could thees vines be used to kill the beetles that are killing the forests off in the west coast ,keeping the insects from spreading.

  10. Yo dawg I heard you like parasites so we put a parasite on your parasite so it can be a parasite to the parasite

  11. Is that in any way related to the fig? Because figs do actually break down their pollinating wasps that get trapped inside

  12. yep, love vines are an annoying weed here in Jamaica. if you don't like someone, throw a few pieces in there yard

  13. I'm about 90% sure I've seen this vine growing in New England, but it all seems to have died off as soon as the weather started turning colder, while the host plants were still green.

  14. can this wasp grow on mistletoe? also, can love vine grow on mistletoe? if they can, imagine parasite living on another parasite and eaten by anotehr parasite…

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