True Facts Parasitoid Wasps: Educational Edition

Added: 2026-06-03

[00:00:01]This right here is Nancy. She's the cockroach. And you'll notice that Nancy is in a bit of a kurfuffle with this jewel wasp. Got it right on the noggin.

[00:00:10]Now, normally, I'd say there's two sides to any argument. But in this case, I think NY is very much in the right. And here's why. You know, that's not a wasp that came across a dead cockroach and said, "Come on, I'll climb inside. You take a picture. It'll be hilarious." No, that's a wasp that just finished eating its way out of the cockroach's body. So, if it seems like Nancy is overreacting a bit, she's not, cuz that wasp wants to lay an egg in her body. And this isn't some isolated case either. Look at this one trying to sneak up on Gary the fruitfly. He's not having it. Sus. It turns out that the majority of wasps do some things that, well, wouldn't be considered polite. And it's not because they're bad. They just think parenting sucks. I know what you're going to say.

[00:00:51]What about the ones that build the yurts with the little hexagon cubbies? Come on. They're good parents. They feed their babies, keep them warm until they're ready to hatch. Well, it turns out that those sorts of wasps are very much in the minority. For most wasps, the idea of feeding a baby is ridiculous. It's a lot easier to just put your baby where the food is, like inside this mealie bug, and then go off and live your best wasp life. I'm telling you, the lengths they go to avoid parenting. I mean, they get creative. Like, take these gall wasps for example. You might have come across a gall before, maybe hanging off a leaf.

[00:01:24]Well, if you look inside some of these galls, what you're going to find is a wasp baby. And that's because when a gall wasp lays its eggs, it slips in a little cocktail that manipulates the plant into growing these little structures. I mean, while the rest of us are building houses out of wood, the gall wasp is like, "Well, wood comes from trees. Have the tree build the house." And what's even better is the babies are vegetarians, hippies. So, they can live in the house and eat it with no parenting. It's brilliant.

[00:01:50]However, there's another sort of wasp that saw this whole gall forming situation and thought, "This is something I can work with." Now, what these wasps do is they lay their eggs inside the gall so that they're very non-vegetarian babies can eat the gall wasp larvy. It's devious. Now, the reason that they can drill into these galls is because they have some good equipment. On the back of this wasp, you can see that black thing sticking out.

[00:02:15]It looks like a stinger, but it's not.

[00:02:17]It's an ovapositor or baby insertion tube. These oapositors are often coiled inside the body or kept inside of a protective sheath when they're not being used. Oh, did you see that? That's like an epic major flinch. What? Yeah, thought so. When it's baby laying time, that sheath will retract, revealing that skinny little needle-like thing there.

[00:02:38]And you can see that the sheath is sometimes used as a guide to give it a little extra stability. But of course, you need something more than an ordinary needle to penetrate wood. If you look close, it's not one long skinny thing, but most often three. And these three parts are held together with a sort of tongue and groove situation. And that means that the parts can slide and move independently of one another. At their tippy tips, these parts of the oipositor can look like little saws with serrated edges. And that's because they are. Here you can see them slide back and forth.

[00:03:09]Looks like the hands of a villain who's about to be greedy.

[00:03:13]By changing which edge of their little saw leads the push, they can either go straight like a knife through butter or take a little turn. Sometimes metals like zinc are incorporated into these little tips to give them a little extra oomph. Look at this little one. Name's Rosemary. You know what she just went and did? She drilled right through the plastic of a petri dish. And there it is. See that little glob? That's an egg she had to squeeze through that skinny tube. But of course, these wasps are trying to lay their egg on a host larvae that they can't see and is inside wood.

[00:03:44]But they can do it because their oapositors seem to have sensory organs on them. You can see this one bending up when it senses carbon dioxide, which is something that a larva is going to give off. And listen, you need yourself a good probe like that. Take Maddie here.

[00:03:58]Sorry, Meline. She hates it when I call her Maddie. When she finds a beetle larva, the first thing she does is inject it with a paralyzing venom. But then before she lays her eggs, she does a good amount of probing. What she's doing is sniffing around to make sure that no one else got here first. I mean, you want your baby to eat that baby in peace. I mean, she might not be the best parent, but she still doesn't want her parasitic larve being parasetized. For one, it's freaking embarrassing. Here comes the egg. It's crazy. It's a freaking miracle is what it is. A passing of kidney stone the size of a bowling ball. Looks like a birthday clown blowing up the long balloon. But even after the egg laying process, wasps have some pretty creative ways of protecting their babies. For example, this caterpillar here is basically babysitting a bunch of wasp pupy. Let me explain. Some wasps are into caterpillars, literally. But I get it.

[00:04:48]They're juicy. I mean, the little ones can be a bit of a challenge. Just stay still. But you go for the big ones, it can be like a full-on rodeo. And some of these caterpillars have defenses like spitting poisonous regurgitant. Look at this wasp stumbling around after an encounter. That's right. You got to wipe it all off. Anyway, when this wasp finally inserts its eggs into the caterpillar's body, it also infects the caterpillar with a virus. It's a virus that has a symbiotic relationship with this sort of wasp. They all have it, but they don't get hurt by it. But once in the caterpillar, it goes to work. The virus slows down the caterpillar's development, which give the wasp babies time to grow. These larae have evolved to eat around the vital stuff which keeps the caterpillar alive even after they emerge from its body and start to spin a cocoon inside which they'll pupate. And that virus seems to modify the caterpillar's behavior to protect those pupy. Here with a different species, you can see that guarding behavior in action. This one's protecting wasp babies that just came out of its body from a hyperaricettoid.

[00:05:49]A wasp that specializes in parasetizing other parasettoid wasps. And yes, if you're wondering, there's a hyper hyperparettoid. And there's other wasps that control the behavior of their hosts. Remember that wasp with the cockroach at the beginning? It injects something right into that cockroach brain, makes it docel like a pet. They just lead back to the layer. Mommy, can we keep it? Oh, don't worry. We're going to keep it. And then remember those gall wasps, the vegetarian ones that eat their way out of the plant tissue? Well, there's another wasp that lays its eggs inside those larae and modifies their behavior. So when it would normally be time to tunnel out of that gall and fly away, they just make this tiny little hole and then block it with their own head. And then I think at this point you know the drill. The parasetid larae eats through the body of the gall wasp and emerges through its head. It's like a horror version of peekaboo. You might have noticed that a lot of these wasps are quite small. The big paricettoids, they get all the attention like the tarantula hawk or the beewolf. I mean they do have the cool names, but look at this one. You know what it's climbing on? That's the leg of a butterfly. But does it have a cool name like butterfly demon? No, it's triagramma. Just rolls off the tongue. Anyway, it's not the butterflies that they're after. They're just hitching a ride. I know what you're thinking, lazy. Use your wings. I mean, many of these micro wasps do have wings, but one of the challenges of being this small is that they experience air almost as if it were a liquid. For them, moving through the air is similar to a bumblebee trying to move through oil.

[00:07:18]Some of the smallest insects in the world are wasps, like really small, like smaller than some amiebas. And they figured out how to scale everything down. Some of their muscles are just a single cell. They got rid of a bunch of nuclei and their neurons. But the parts are pretty much all there. If they have wings at this size, they're basically feather dusters with all these little bristles that increase surface area without adding all the weight. So, if you're a really small wasp and want to cover any distance, hitchhiking on a butterfly is not a bad idea, especially if what you're after are butterfly eggs.

[00:07:51]In this case, it's the cabbage white butterfly, a serious agricultural pest.

[00:07:56]And that's the thing about parasettoid wasps. They're at the front lines of controlling the world's insect population. You might have some issues with how they go about it, but for example, the spotted lantern fly is eating its way through the eastern United States. In part because unlike where they're from, we don't have the species of wasp that targets them.

[00:08:14]There's a wasp for everything. It's crazy. You know those moths that eat through all your clothes in your closet?

[00:08:19]There's a wasp for that. You can buy them and come in packs of like 12,000.

[00:08:24]And once the moth eggs are gone, they're gone, too. Your clothes won't have any holes, but you'll be wearing the tiny dead bodies from a great battle. Well, slaughter really. Can have a nice cashmere peppered with 10,000 dead moth babies. Got a situation with the caterpillar.

[00:08:42]Got a situation with a moth.

[00:08:47]Got a situation with some caterpillar.

[00:08:52]What you need is a WP.

[00:08:56]What you need is a WP.

[00:09:00]What you need is a WP.

[00:09:06]What you need is a w.

[00:09:11]What you need is a W A S P A S A