If you've ever tried to grow tomatoes outdoors, you've probably encountered a hornworm.

These fleshy green caterpillars can devour a tomato plant overnight, leaving nothing behind but the stems and their signature large green frass, a fancy word for insect droppings.

They blend in perfectly with the green of tomato plants, making it hard to spot them before they've done their damage, although there is a secret trick to picking them out.

But gardeners have a tiny partner in their battle against this voracious caterpillar.

Enter brackenid wasps.

I found several tobacco hornworms in my garden, and I was really excited to see that these guys were infested with brackenid wasp larvae.

See those tiny little white cocoons?

Oh, I just saw another one.

Oh, very good.

My friend, Dr. Adrian Smith, is really skilled at high-speed photography, and he uses it to document insect movement.

So I collected these parasitized caterpillars and brought them into his lab to see if he could capture the tiny wasps emerging.

You know, totally normal friend things.

Adrian ended up photographing them over many days until the magic moment happened and several brackenid wasps emerged from their cocoons.

(upbeat music) From the caterpillar's perspective, this might seem pretty brutal, but it's a natural cycle that can repeat itself in your garden as a form of natural pest control if you leave parasitized caterpillars alone so the wasps can hatch out and continue the cycle.

If you want to look for hornworm caterpillars more effectively before they demolish your plants, get yourself a UV flashlight and take a nighttime stroll amongst your tomato plants.

Look at those guys.

You can really see them.

Holy moly.

Hornworms glow or fluoresce under ultraviolet light due to pigments in their skin.

There he is.

Wow.

Nice try, guys.

So much for blending in.

[whimsical music]