This orchard is swarming with Argentine ants,  but they’re not here for the juicy oranges.

They’ve found something way better.

They’re obsessed with these  delicate candy ribbons … … which happen to be coming out of the butts  of these tiny insects: Asian citrus psyllids.

They suck sap from citrus trees.

And produce the prettiest  of poops, called honeydew.

The ants ranch the psyllids like cattle,   putting their lives on the line to  protect their herd from predators.

This ladybug larva is easily deterred.

But this hoverfly larva takes more convincing.

Even more dangerous to psyllids  is this tiny parasitoid wasp.

It’s looking for a host for its eggs.

But the ants are having none of that.

The psyllids and their ant allies  have an even bigger threat.

Citrus growers who are desperate to  keep the pests out of their orchards.

That’s because psyllids can spread bacteria   in their saliva that causes a  disease called citrus greening.

The disease turns leaves yellow  and makes fruit green and bitter.

Citrus growers can spray pesticides,  but those kill the helpful insects too … … leaving the trees undefended when the  psyllids inevitably find their way back.

Plus spraying only gets at some of the ants,  since most are safely underground at any one time.

So let’s recap: it’s psyllids  and their ant bodyguards vs.   citrus growers, predators and parasites.

Still with me?

Because psyllids are so tough to get at,   citrus growers decided to take  out their ant accomplices instead.

By studying the ants’ behavior, researchers  at the University of California, Riverside,   found a weakness they could exploit.

Ants follow the easiest path from tree to tree.

They’re all about efficiency.

They turn the orchard’s irrigation  pipes into mini highways.

Researchers set up sensors on the pipes that use   invisible infrared beams to measure  how many ants go marching through.

In the most trafficked areas, researchers  spread these tiny biodegradable balls.

They’re soaked in sugar water laced  with a slow- acting insecticide.

The ants slurp up the poison and bring  it back to share with the colony.

This targeted technique uses just a fraction  of the pesticide that spraying would.

With fewer of their bodyguards around, the  psyllids are more exposed to their enemies.

The parasitoid wasp moves right on in.

And lays an egg on the psyllid’s soft underside.

That wasp egg hatches and the larva  right here burrows into the psyllid,   devouring it from the inside.

When the wasp is all grown up, it chews its way  out, right through the top of the dead psyllid.

Glad they’re on our side, huh?

It’s a story of unlikely allies, fighting an  ongoing battle, for the sweetest of rewards.