Citrus Psyllids Bribe Ants With Strings Of Candy Poop | Deep Look

Asian citrus psyllids transmit a disease that can ruin your oranges. Even worse, Argentine ants protect them in exchange for the psyllids' delicate ribbons of sugary poop, called honeydew. So, researchers are helping orange growers fight back with invisible lasers, ghastly wasps and more trickery.

DEEP LOOK is a ultra-HD (4K) short video series created by KQED San Francisco and presented by PBS Digital Studios. See the unseen at the very edge of our visible world. Explore big scientific mysteries by going incredibly small.

---

A tiny insect called the Asian citrus psyllid is threatening your oranges, lemons and limes.
Smaller than a grain of rice, the agricultural pest sucks the sap from citrus trees and in doing so spreads a disease that ruins the fruit and eventually kills the citrus trees.

“It's pretty straightforward to tell if you have an Asian citrus psyllid infestation in your citrus,” says Mark Hoddle, who leads a laboratory at UC Riverside that studies the pest and how to beat it. “Just check the tender young green leaves at the tips of the branches. If you see the white curly cues, the insect poop dripping off of those leaves, that's almost certainly a characteristic symptom of an Asian citrus psyllid infestation.”

Hoddle’s team is studying novel ways to keep psyllids out of citrus orchards, but that task is complicated by the psyllid’s relationship with another insect, the Argentine ant.

“Their relationship is rather sinister,” says Hoddle. “The Argentine ants harvest the honey dew that the Asian citrus psyllid nymphs excrete because it's nice and sugary and the ants love eating sugar. In return for providing that sweet delicacy, the ants protect the Asian citrus psyllids from their natural enemies like the predators and the parasitic wasps that we have introduced from Pakistan.”

“The psyllids need protection from the ants because they lack defense systems,” says Hoddle. “They have recruited mercenaries to protect them.”

So to protect the valuable citrus industry, Hoddle and his team are going after the psyllids’ ant bodyguards.

--

--- What is the Asian citrus psyllid?
The Asian citrus psyllid (Diaphorina citri) is a tiny insect, smaller than a grain of rice, that can spread a plant disease called citrus greening. The agricultural pest sucks the sap of citrus trees and produces strings of sugary poop.

---What is citrus greening?
Also called huánglóngbìng or HLB, citrus greening is a disease caused by a bacterial infection that causes green bitter fruit and eventually kills citrus trees. Asian citrus psyllids transmit the disease when they feed on citrus trees.

--- What does citrus greening look like?
Citrus greening often causes patches of leaves to turn a blotchy yellow and fruit that is green and bitter. These yellow patches are typically asymmetric, which helps tell it apart from other issues like nutrient deficiencies. Trees eventually lose their leaves, stop producing fruit and die.

---+ Find additional resources and a transcript on KQED Science:

---+ For more information:

---+ Shoutout!

🏆Congratulations🏆 to these fans on our Community Tab for tackling our GIF challenge!

All 3 answers:「Formula Zero EX」

2 out of 3:

Hyperion
Muhammad Haziq Hilmi 1012
Preet Budhwani
hussain e
IncoherentBabbler

---+ Thank you to our Top Patreon Supporters ($10+ per month)!

Burt Humburg
Karen Reynolds
Companion Cube
Allison & Maka Masuda
Daisuke Goto
David Deshpande
Chris B Emrick
Tianxing Wang
Wade Tregaskis
Mark Jobes
Blanca Vides
Kevin Judge
Laurel Przybylski
monoirre
Supernovabetty
Roberta K Wright
Titania Juang
Syniurge
El Samuels
KW
Carrie Mukaida
Nicky Orino
Jellyman
Cristen Rasmussen
Mehdi
Kelly Hong
Cindy McGill
SueEllen McCann
Shelley Pearson Cranshaw
Laurel Przybylski
Nicolette Ray
Noreen Herrington
Louis O'Neill
Caitlin McDonough
Elizabeth Ann Ditz
Jeremiah Sullivan
Delphine Tseng
Levi Cai
TierZoo

---+ Follow Deep Look and KQED Science on social:


---+ About KQED

KQED, an NPR and PBS affiliate in San Francisco, CA, serves Northern California and beyond with a public-supported alternative to commercial TV, Radio and web media.

Funding for Deep Look is provided in part by PBS Digital Studios. Deep Look is a project of KQED Science, the largest science and environment reporting unit in California. KQED Science is supported by the Dirk and Charlene Kabcenell Foundation, Campaign 21 and the members of KQED.
#citruspsyllid

[Temarah]

😂😂 the ant really casually strolled past and kicked the wasp off

[octapusxft]

The Psyllids and Ant relationship puts the term "sugar daddy" in a different perspective

[SergTTL]

I'm so repulsed by insects. But I'm basically forced to watch them on this channel, because of the superb production quality of these videos. Everything is just perfect - the filming, the script, the presentation. So I'm watching these with a sour face and with admiration.

[junrymalagsic]

Hope Laura narrates all of deep look videos. Her voice really suits every episode. Great work as always!

[Leeleeify]

Why did I die of laughter when the ant knocked out the wasp 😂

[reionj]

It's sad that pesticides harm other important insect species, at least they found an alternative way. I am glad to see that, thanks for sharing that with us deep look, 💯😌

[renatocann]

Love this stuff. I remember reading years ago about similar situations where some trees upon "noticing" that their leaves were being eaten (by I want to say caterpillars) were believed to release a sort of chemical signal that actually attracts those parasitoid wasps. Rather than stringy poop the caterpillars happened to produce a glob of some sweet secretion on their back that attracted ants and led to the ants protecting them from the wasps. Blew my mind, like we all know about parasites and symbiosis and whatnot but I had no idea how complex it could be!

[patrickpelletier]

I usually give these videos a thumbs up even before watching them. Because I know it’s going to be fantastic. This one was no exception it was fantastic thank you so much!

[ChilledfishStick]

I've just seen a video by Tom Scott about a parasitoid wasp, Perhaps this one (probably not), that are grown by the US government, and given to farmers, to combat stinkbugs.
It's very cool to see more wasps fighting the good fight. Amazing video!

[Bigbbs_umchileanywaysso]

1:37 the ant literally flicked that wasp off💀✋🏽

[tuckerricklefs]

I think it's worth noting that both Argentine ants and Asian citrus psyllids are invasive in the US, as there names would suggest. While specifically targeting the ants might seem cruel, it is a lot more ecologically sustainable than spraying pesticide, which would do the exact same thing, but to local insects as well.

[killermakd]

You guys have beat Animal Planet when it comes to the visuals and commentary. Kudos!! (With all respect to Sir David Attenborough). I would be very grateful if you also make a few videos on our insect friends that inhabit our homes. Ways to safely warn them away, or possibly remove them. Locusts, mites, etc. anything really. A bit more on their technicalities.

[GreySchezwan]

Amazing informative content in your videos as always, can't believe it's free to enjoy.

[MrGamerCaptain]

glad to see the videos are connected to each other. lot's of research material to be had from a single area.

[shortsparks]

Sometimes when life sucks, I look at this video and feel better knowing I wasn’t born a Citrus Psyllid.

[ultraameise]

Thank you now I know more about these insects and even learned what the ladybug larvas look like :)

[justinjyeung]

This was a really cool part-2 follow-up to the last video! Especially since it covered this 2-pronged approach to dealing with the psylids, both by planting alyssum to attract hoverflies and by using honeydew-pesticides to thin down the ant population! Just goes to show how different components of an ecosystem interact in unique ways :)

[shegosilver]

I like how humans are learning to play chess with the ecosystem.

[GrandTheftDiamonds]

1:39 "But the ants are having none of that."
*yeets wasp into oblivion*

[greened_kaboomer]

1:40 bro kicked the wasp off and then minded its own business