Welcome to the Good Growing podcast.

I am Chris Imra, vorticulture educator with University of Illinois Extension coming at you from Macomb, Illinois.

Now today, it is the spooky episode, and you notice I sound a little bit different.

I also look a little bit different.

That's because I, if you're listening, am a bears super fan.

I've got my bears gear on.

I got my my bears hat on, and I am, saluting as always to the, the, you know, almost patron saint, Ditka.

He's almost there.

He needs one more miracle.

He's gonna get there, though.

So alright.

And today, we are talking parasites.

Now parasites, that's gonna be so much fun.

We're gonna be speaking with doctor Kacie Athey, but this is beyond me.

So I definitely need help today because all I can do is maintain this very poor Chicago accent.

So I am joined as always every single week by horticulture educator Ken Johnson in Jacksonville.

Oh my gosh.

Hello, Ken.

I may the force not be with you.

You're the bad one.

Go ahead, Ken.

Hello, Chris.

I'm not gonna I'm not gonna try the voice because I can't I can't top you.

So

You're not gonna do the voice?

I wish Darth Vader had a giant orange beard poking out from his mask.

I did wear my Darth Vader shirt.

Oh my gosh.

What are we missing with Vader has a beard?

You can tune in on YouTube and see it here, folks.

Darth Vader with a beard.

I love this.

Yeah.

I'm not sure how long this mask is gonna stay on because my glasses are already fogged up, I can barely see.

So

And and you do sound like you're talking into a tin can,so.

Oh my gosh.

Ken, are are you ready for the spooky episode today?

I am.

I I am excited for it.

Well, excellent.

Well, I I I you I know you have been excited for this.

I I also you know, I have my mug of of of of cold draft here, which is technically just, apple juice, but, you know, gotta have appearances.

I also have my Polish sausage.

Let me get this thing ready.

I will be eating and drinking throughout this event here that we have going on.

So we had better we had better get started.

Right, Ken?

Exactly.

Alright.

Excellent.

Well, I am so happy to welcome all the way from the Champaign Of Urbana.

Welcome, doctor Kacie Athey, to the Good Growing podcast broadcast here in in Illinois.

Hey, doctor Athey.

How are doing?

I'm good.

Thank you.

Thanks for having me.

Now,can you explain your costume to us, please?

Because this is I I love this costume.

It is a very good one.

Yes.

So it is not emperor Palpatine, even though it kinda looks that way.

I am the mothman or mothwoman, I suppose, in this particular case.

And you can't see all of it, but but, yes, I'm the mothman, which seemed appropriate since I'm an entomologist.

It it is an excellent urban legend, Mothman.

I don't know.

Well, I have to ask you.

Do you believe in the Mothman?

I don't know.

Okay.

I'm not sure that I believe encrypted so much as I just really like the stories, and I promise not to haunt bridges or make them fall down.

Of the few things I know about Mothman, it is from the movie, The Mothman.

And then the I remember bridges being a pivotal role in that movie.

It's like all bridges.

Yes.

For some reason, the Mothman really wants to get rid of bridges.

Yeah.

I'm sure people who are really into cryptids probably have a much better explanation than I do.

Because space space moth, you know, maybe something like that.

I don't know.

They just anti bridge.

Yes.

Yes.

Mhmm.

Yeah.

Well, Kacie, we are so happy to have you on today, and we're talking parasites.

And so I guess we should dive into this.

Ken, would you mind kicking us off, please, before my my Polish sausage here gets too cold?

I can do that.

So I guess first question is kinda setting the table for all this.

What exactly are parasites?

And then a follow-up to that is how are they different than diseases, or are they basically the same?

Well, so, yeah, parasites kind of you could separate parasites and diseases from each other a little bit.

So a parasite would cause a disease, right, in a person.

But parasites live on or in a host organism, and they feed off of them, which is a little bit different than bacteria and viruses that aren't really feeding off of the the host organism.

And generally speaking, the other thing about parasites is we tend to think of them as not really killing their host so much, although, certainly, that happens a fair amount.

And and, obviously, bacteria and viruses don't always kill their host, but sort of a a hallmark of parasites when we think about that is trying to keep the host alive because they're actively feeding off of that host.

That that's a really good distinction.

I we as we're doing a little research for the show, Ken and I were talking, and, and we were like, oh, well, how is a virus not a parasite?

But I like how you explain it.

Because, like, yeah, I guess a virus, it kinda hijacks.

It, like, takes over stuff.

Yep.

The parasite is is is literally, like, siphoning energy off of

Yes.

Yes.

That other host.

So Yep.

Yeah.

It it has opened up.

It is so clear now.

Thank We we we have so many parasites out and around us.

And so, I don't know.

It what would you say would be the most common parasite out there?

Is there a common parasite that humans typically encounter?

Well so I suppose that's a hard question, but I suppose we can think about sort of, like, the parasite that is scare scariest for humans or had the most impact on humans writ large.

And so, of course, the the most common one is malaria.

If you think about malaria, malaria is a parasite, and it the fact that malaria exists actually makes mosquitoes the most dangerous animal on the planet because they vector malaria.

And so let's see.

In 2023, I looked this up before this.

There were two hundred and sixty three million cases of malaria worldwide, and almost six hundred thousand people died from malaria in 2023.

And so that is you know, we think of malaria as a disease because it is, but it is caused by a parasite that is then, you know, feeding off of the host, us, and then also its other host, which is mosquitoes.

And the other thing to keep in mind, I think, when we think about parasites is that their life cycles can be really complex.

If you think about a bacteria, a bacteria is going to infect someone, and it doesn't need to move somewhere else to complete its life cycle.

Like, it can enter a body and do all of its things right there, nothing else necessary.

A lot of parasites, that's not the case.

So malaria, as an example, needs a mosquito, and it needs a vertebrate of some sort.

And, of course, in the case of the malaria that we talk about, it's humans.

But it cannot complete its life cycle if it doesn't have both of those things.

And so I think the interest for me with parasites has always been that they are complicated, that thinking about life cycles like this and thinking about how they persist and why, I suppose, was always really interesting, especially with internal parasites.

We get that a little less with things that are feeding on the outside of an animal.

So if you think about, like, lice, right, they don't have complex life cycles.

They can feed on the same vertebrate, reproduce, do all their things.

Really, a lot of the complex ones are the ones that end up inside bodies.

It's true.

Well, speaking of the more external, just yesterday, we were had a master naturalist training, and we are October yesterday was October 23.

We had dipped right into to the freezing point, and I pulled a a black legged tick off of me after the class.

So there's they're still out.

Yeah.

Yes.

Even though it's cold outside now.

Yes.

Yeah.

Yeah.

And, I mean, we could talk for a long time about ticks and the fact that there are more of them and the fact that their ranges are expanding.

You know?

So it's not as if external parasitoids aren't also or parasites aren't also interesting or, you know, to be paid attention to.

Mhmm.

They're just their life cycles just tend to be less complex.

Yeah.

And this should become a very long podcast.

Oh, it could.

Oh, it could.

Let me get the book out, and it's, like, this big.

Yeah.

There's a lot to uncover here.

So, yeah, we're dipping our toes today.

Yes.

So I think that we had some came up with some things to talk about.

You know, say things.

So the first ones were kinda the the parasites we may encounter in our garden for better or for worse, I guess.

So or the parasitoid wasps, the first one we wanna talk about, and some of the Mhmm.

Unique stuff about them.

Yeah.

Yeah.

So I should mention that one of my degrees is basically in parasitoid wasps.

I I worked in a lab that we did naming of new species, classifying.

And in fact, fun fact, there is a wasp that is named after me.

A parasitoid wasp, which is fun.

No.

I don't know what it parasitizes because it's based on a specimen.

But, anyway, parasitoid

wasp Can

you name drop can you name drop this wasp?

Is Oh,

that's a good question.

So it's the the specific epithet on it, I think it's Alabagrus kaciejoae is what it is, I think.

That's cool.

If I remember correctly.

Alright.

Sorry to interrupt.

I was just like, oh, no.

No.

No.

It's curious.

I wanna know.

I

gotta take my I gotta take this hood off.

It keeps falling down, and I do look like Palpatine if I'm not careful.

So I gotta gotta do something different.

We can just focus on the necklace that looks a little moth man y.

So, yes, I'm very interested in parasitoids.

And I should mention that parasitoids are it's a different word than parasite.

Right?

And sort of the distinction here and kind of the thing we generally talk about is that parasitoids always, pretty much always, kill their hosts.

There's no surviving unless the host mounts a immune attack or some other thing.

If the parasitoid is a is successful and it gets to adulthood, its host is gonna die.

And so that's, you know, the reason why we're not just saying parasite wasps because you don't if you're attacked by a parasitoid, you're not gonna survive that.

And I also I'm going to talk about wasps, but I should mention that parasitoids, there are kind of a bunch of groups that contain them.

So there's lots of parasitoid flies, and those are going be ones you're going to encounter in your garden as well.

There are parasitoid moths.

There's a there's a whole family of of moths that attack leafhoppers and things like that.

And then there's other sort of weirdos and other families.

So parasitoid moths.

There's something called twisted wing parasites, but those trend more towards actually parasites.

Caddisflies, if any of the audience knows what a caddisfly is, there's a few of those that are parasitoids.

And then things related to lacewings.

So members of Neuropterans, there's some parasitoids in there, and there's parasitoid beetles too.

So the group itself is really diverse, if you will, but the majority of them are wasps.

The diversity is wasps.

That's, you know, generally what we focus on even though there's lots of cool other stuff in the other groups.

And I would argue they're some of the coolest animals for a variety of reasons.

They go after all kinds of different hosts.

Sometimes their life cycles are really simple.

So you might have something that just here's a caterpillar.

Parasitoid lays its eggs in caterpillar, develops, pops out.

Simple.

Some are not so simple, and some are implausible, if you will.

And so I also wanna mention something.

This is a Halloween episode.

So something that entomologists talk about a lot is that these are chest burster from alien.

Right?

Everybody knows what that is.

That's a parasitoid.

That's what that is.

It's not a parasite because you're not gonna live through it.

And the when the the alien pops out, that is not all that different from a parasitoid emerging from a thing that it's not supposed to be in.

And the other thing that in my experience with parasitoids, there's a lot of people who are butterfly collectors.

And the absolute worst thing that happens to these people, they've got their caterpillars and they're rearing them.

They're feeding them leaves, hoping to get some special butterfly out, and then they either get a fly or a wasp.

And I got to give a talk to a group of these people once, and my talk was all about parasitoids, and I think I horrified them.

They were not amused.

They did not like it because I was like, look at all these cool caterpillars, and look at all the cool wasps that came out.

They were not having a good time.

I was.

And so, you know, sort of bursts all their hopes when it's like, here's a cool wasp that popped out, not the butterfly you were hoping for.

Burst their hopes like an alien out of a chest.

Yes.

That is exactly right.

Exactly right.

Yeah.

It was it was more fun than it should have been for me, to be honest.

I'm sorry, Kentucky Lepidopter Society.

I I I've been there.

I've reared a few monarch caterpillars with my kids, and then all of a sudden from the as it forms its chrysalis, it turns not the right color, very dark, gooey looking color.

And then these little maggoty looking things start dropping like, you know, special forces from a helicopter.

They just, like, drop down, and they, like, drop down on the bottom of our cage.

I'm like, woah.

What is that?

My kids are like, you know, so yeah.

Terrifying if you're a child.

Yes.

Yes.

Circle of life.

That's right.

And, of course, for me, I'd be like, that's super cool.

But, yeah, a lot a lot of people of course, people want their monarchs.

But one thing to think about is if you have a parasitoid that specializes on monarchs, although we all think monarchs are really, really cool because they are, that specialist parasitoid is also a unique animal that, you know, needs the monarch to survive.

And so without monarchs, we also wouldn't have that weirdo that's coming out of your monarchs.

So, you know, I like to think of it that, generally speaking, if you have, you know, native parasitoids and native hosts, you're generally not gonna have so many of them that the parasitoid is gonna wipe out the host because then the parasitoid, if it's a specialist, doesn't have anywhere else to go.

So it behooves them not to do that.

And I kind of thought that the next place to go when I'm talking about parasitoids is to talk about a parasitoid that probably everybody has seen before, whether or not you know that's what it is.

So let's think about our gardens.

And for people who grow tomatoes especially, you'll think about the giant giant caterpillar with the hornworm on the the horn on the back that is gonna be eating your tomatoes a little bit every year.

And at some point in the year, at least one of those on your tomatoes is going to sprout a bunch of white things out of the back of it.

I've heard people say that these are eggs.

I've heard a lot of different interpretations of that.

Those are parasitoid wasps.

So I'm gonna go through, you know, a little bit about the tobacco hornworm and its very, very prominent parasitoid.

So the wasps are flying around about the time that those caterpillars are about halfway the size that they're going to be, although they can attack at different times.

And she'll go around.

And a lot of parasitoids actually aren't attracted to their hosts.

So it's not the caterpillar that the parasitoid is, like, cluing in on.

It's actually the plant.

So as the caterpillar chomps on the plant, it's releasing chemicals that the parasitoid is actually queuing in on first.

And then the parasitoid will go and find its host as a result of that.

So she's gonna get there, and she's gonna lay eggs inside that caterpillar.

Some parasitoids lay one egg inside each host.

So we have a lot of parasitoids of eggs, squash bug eggs, stink bug eggs.

They're gonna lay one egg inside of that egg because it can't handle anything else.

A tobacco hornworm can handle a whole lot more than that.

So any given female is gonna lay just a bunch of eggs inside that caterpillar.

The caterpillar does have some defenses.

So a caterpillar can move around a lot.

They can vomit in the general direction of the parasitoid.

They can poop in the general direction of the parasitoid.

So a lot of times, the parasitoids will actually attack, like, behind their head because it's the hardest place for them to get to.

So then she lays her eggs, and they'll hatch in there, and they'll start feeding on that caterpillar inside.

Now I found a thing that was actually really, really interesting.

There was one I found a study, and there was one tobacco hornworm that had 816 of these Cotesia larvae inside of it, inside of one, which I can't even fathom how that works.

816.

Now that wouldn't have been from one female.

Right?

So a wasp comes and does it.

Maybe another wasp comes on and is like, looks like a good caterpillar.

I'll lay my eggs in that too.

The maximum number that could actually come out was 200.

So think about a tobacco hornworm with those little white cocoons on the outside, and think about one being covered in 200 of them and those things surviving.

And so large numbers here with these caterpillars.

And it's I think it's really impressive that they had enough to eat at all to survive for 200 of them to come out.

And so one other thing is with these parasitoids, they don't actually affect what the hormone does for most of the time that they're in there.

So some parasitoids can make a caterpillar or their host eat more, can make it eat less, can make it behave a little bit differently depending on what will be beneficial to them.

In the case of the tobacco hornworm, those Cotesia wasps inside there aren't making it do anything.

It's just eaten.

It's doing its thing.

They do stop it eating once they spin those cocoons and come out.

So when you see that hornworm in your garden and it's got all those cocoons on its back, all of the white things, it's no longer eating because the parasitoids have stopped it from doing that at this point.

And I don't think there's a concrete reason for that, but there's some evidence that unparasitized tobacco hornworms will eat Cotesia cocoons.

And so there's some thought that maybe the parasitoid stops them from eating so the caterpillar doesn't go, hey.

What are these?

I could eat these.

So it's not gonna eat at all, So then it isn't gonna eat the cocoons all over its body, possibly.

That's a hypothesis anyway.

But we they do know it has been observed that the unparasitized ones will go around and eat.

Like, if they fall off, sometimes they'll fall off and the caterpillars will eat them.

Interesting.

Yeah.

One thing one little digression with insects is we often talk about things that are like caterpillars or herbivores.

Right?

You know, all caterpillars.

Well, most.

But if there's something easy to eat that's full of protein, things are gonna chomp that down, whether it's like a pupa in front of you that's easy to eat or an egg or something like that.

So that's not out of the realm of of possibilities as my aside.

So that's kind of that kinda wraps up those guys as far as what you will normally see pretty predominantly in your gardens for parasitoids.

I will mention one more garden parasitoid.

If you have aphids in your garden, you probably have parasitoids.

So aphids, if you ever see them where they look like they're kind of now made of paper and they're ballooned up, that's evidence of a wasp that got in there and attacked them.

And so when you're in your garden, if you're just paying a little bit more attention, you can actually see evidence of parasitoids probably every year, at least those two for sure.

If not some other interesting things, but those are the most predominant ones, I would say, in the garden parasitized wise.

A

fun one is just to look at milkweed or I have some tulip poplars also.

They always have aphids on them.

And just look under the leaves, look on them, and you see you could use, like, a hand lens or something going real close.

That wasp cuts a tiny little hole out the the back end of that aphid, and it just bursts out just like just like an alien.

So Yep.

Yeah.

And it does look like somebody blew up the aphid like a balloon and then made it out of paper mache.

Mhmm.

It it's it's really it's really wild.

And fun fact, that's not just, like, one species.

It seems like things that parasitize aphids, which are not very closely related, the the two groups that do it, they all make the aphids do that even though they're not related to each other, which is kind of interesting.

There's not a different way of parasitizing, even though they're very un two very unrelated groups of parasite parasitoids.

You you can pop popcorn many different ways, I suppose, fire, in a microwave, on a stove.

In the end.

So you can pop an aphid.

There you go.

Popping aphids.

That's my new band, Popping Aphids.

Yep.

Beautiful.

Beautiful.

So the the next group that I wanna kind of talk about is technically probably in gardens.

It's probably most places.

It's just not very commonly encountered or thought about, I would say.

And the reason I wanted to talk about it is because its life cycles are so implausible.

So whereas the tobacco hornworm, that, again, that wasp just needs to find a tobacco hornworm.

And she can lay her eggs directly in there, and she can walk away, and she can feel like, yep.

I got it.

I've I've done my job.

My babies are where they're supposed to be, giving them the best chance.

And sometimes that's not how it works.

So sometimes it's complicated that simple, I'm just gonna lay my eggs inside this thing, best chance to exist.

Sometimes it's complicated because of something called hyperparasitoids.

So hyperparasitoids are parasitoids of parasitoids.

So if I'm gonna go back to the tobacco wormworm example, when those cocoons come out, there's another wasp that comes out and goes, Now that's my host, and goes and legs her lays her egg inside that cocoon.

So then instead of getting Cotesia out of there, you get something else.

Some other wasp pops out because its host is not the tobacco hornworm.

Its host is actually Cotesia.

So that's more complicated.

Now that one would be easier for wasp mom.

Right?

Because wasp mom can literally see those.

What if she's going after a the Cotesia that's inside?

So now she has to find a hornworm that's not outside visibly parasitized, but she's gotta get her eggs inside of there, and then her babies have to find their host inside the caterpillar.

Little more complicated.

Although with Cotesia and the hornworms, there are cues again that the plants giving off the tobacco hornworm actually has cues she can pick up on that she knows that is parasitized.

So she's not she's not going in blind.

She's not just laying her eggs in a thing and hoping that the host is actually in there.

And so it's cool.

It's complicated, but it actually sounds pretty plausible.

Again, it's just using cues with the environment, knowing that that's inside of there.

A lot of parasitoids attack things that are hidden, things in wood, and so the mom has to do something to know that her host is in fact in there, get her babies inside of that.

All kinds of ways they do that.

I can understand that.

Seems pretty straightforward.

That brings me to trigonalids, which do not have a common name, so I'm just gonna keep saying trigonalids this whole time.

It's a family of wasps.

And I swear the wasp mom does not want her babies to live.

Not true, but it seems like that.

So, again, these probably are at times in your gardens, near your houses, but they are definitely found more commonly in forest systems or, like, more wild systems, I think, when we actually find them.

So I I actually have two examples for trigonalids, both complicated in different ways.

But I want to start with I've been talking about how parasites generally are laying their eggs directly on their host or in their host.

Right?

Easiest way to do it.

Trigonads do not do that.

They lay their eggs on leaves, and they lay thousands of them on leaves.

And they lay them pretty much wherever they want, irrespective of whether there's a potential host anywhere near.

They are not the only ones that do this.

So a lot of the the parasitoid flies will lay their eggs on leaves because they have to be eaten.

That's how they have to get in the body of their host.

But the tachinid mom will lay her eggs near a host.

She'll be like, well, the eggs should go here because the host is right here, so it's tricky and old moms don't do that.

They're just like, well, this is a leaf.

This will be fine.

I'll just throw some over there.

And truly, there's never been any evidence that they lay them anywhere near potential hosts.

They don't do that.

They just lay them.

So I I like to think, you know, it's sort of willy nilly.

They just lay some, go to the next plant, lay it willy nilly.

So it's like, good luck, children.

May the odds be ever in your favor.

It's a hunger wasp hunger games.

A little bit.

So now now the eggs are just hanging out on a plant.

They're just there.

And by chance, a caterpillar or a soft fly needs to eat them.

So okay.

Sure.

That's actually, again, not that complicated.

Cool.

And it does it does seem simple at this point, except that's not the host.

That's not the host for the trigonalid.

Not yet, anyway.

Their host is a ichneumonid wasp or a tachinid fly, depending on the species, that's already inside of that caterpillar or sawfly.

And remember, it's willy nilly.

So it's not like the mom put it near a parasitized already parasitized thing.

That thing could have nothing in it.

So the trigonalidae could end up inside of the proper caterpillar, but there's no Echneumonid in there, so game over.

Now if it is, then they yay.

They get to go feed off of that ichneumonid or tachinid.

Okay.

Great.

So that part has happened.

Then when that thing pupates inside well, now they actually do have to eat the sawfly or the caterpillar.

So then they have to go out of the sawfly or the caterpillar and then feed on the outside of that and consume that.

So they can't just eat what we thought was their primary host.

They then have to eat the secondary host, and then that's how that one ends.

Complicated and seemingly implausible, especially if they're more specific, you know, if it has to be a certain species.

Now, of course, the fact that she lays thousands of eggs is probably the reason why we've ever heard of these animals at all.

But that one's actually less complicated, I think.

So the other one is the same.

So it's all the same.

Just willy nilly eggs.

Caterpillar or softly has to eat it, and then something like a paper wasp has to come along and take that softly or that caterpillar to feed its babies with that softly or the caterpillar.

Because the actual host for the trigonalid is the baby paper wasp, not the softly or the caterpillar.

So then so then that thing has to be taken to and it can be other vespids, but I'm using paper wasp as an example.

Has to be taken to the nest, and it can either get in by being eaten by the baby paper wasp and then exiting the gut there and then you know?

Or if the the the paper wasp mom chews up the caterpillar and baby birds it, it can also do it that way.

It can also get in but it has to get into the paper wasp larva because that is its host.

And so then it can, you know, do its thing and feed on the host and then, you know, become an adult.

But that one is the one that gets me every time.

Because even if you again, you end up in the soft fly or the caterpillar, but if a paper wasp or something doesn't come and take you and take you to its baby, you then don't survive either.

So just implausible life cycles that just do not make any sense but have persisted, again, because all she does is lay so many eggs in the environment that by chance, a couple of those are gonna become adults again.

So just the wildest life cycle and one of my favorite stories.

It makes you wonder how that something like that either even evolved.

Yeah.

Like

Agreed.

Is it still evolving maybe?

I don't know.

That sounds like there's a a few things you could cut out there and and be more efficient in your energy.

And, yeah, it I feel like there's may maybe it's in the process of specialization.

I don't know.

Well and if you think about some things, so like I mentioned with tobacco hornworms, the parasitoids trying to attack those directly, often there is antagonistic interactions.

Right?

Because these hosts aren't just helpless.

They have ways of fighting back.

And so if you're going directly after something, you stand the chance of being injured, you stand the chance of a variety of things.

If you are just throwing eggs into the environment, you yourself don't don't have those antagonistic interactions.

And so maybe there's something to that as well where it's a different type of strategy.

Like, well, I'll just put instead of putting my energy into fighting this thing, I'm gonna put my energy into producing absurd amounts of eggs and Yeah.

Hoping for the best.

Do

you know or or is it known, like, the one that has to get into the wasp?

Does that alter the caterpillar or sow fly's behavior to, like, make them go into the open more where they're found easier?

Or Yeah.

I didn't see that when I was reading papers, and I'm not sure if that is known.

It probably is.

I just you know, a lot of the papers that I was looking at and what I was doing would focus so much on the weird life cycle part that they don't talk as much about, like, the actual behavior of, like, the soft lye or the caterpillar as far as, yeah, whether it's putting itself out in the open so it gets taken away by a paper wasp or things like that, which it absolutely could be.

I mean, the behavioral manipulation, again, even with the hornworm, it's so much as, like, we're just not gonna eat.

There there there's definitely that possibility that it does something like that.

I I highly recommend everyone whenever you come across something like this, spend time to observe it.

Because I I did find a a hornworm this year that had all of the the cocoons on it, And I saw now now after hearing you, Kacie, I saw all these tiny wasps on there.

But I I remember watching a video many years ago, like, when when the hornworm parasitoid, when that comes out, it cuts a little hole in the top of the cocoon.

I remember saying, I didn't see any holes in the tops of the cocoons, but there's a little tiny wasp on the cocoons.

I'm thinking, well, maybe this is just mom coming back to lay more eggs.

I didn't know.

I didn't know.

Yeah.

Maybe it was the parasitoids.

Oh my gosh.

Yeah.

I bet it was.

Yeah.

Yeah.

And often hypoparitoids are smaller because what they're going after is usually smaller.

And so if you see something really little on there, that might be what it is.

And that's not always true, but there's sort of a trend for that.

But yeah.

And I think I I feel like there are a few, like, hyperparastoids of hyperparasitoids as well.

But, you know, that that's

The Russian nesting doll situation here.

I I think what about there there's another, though.

I don't know, Ken.

Can you wanna ask this question?

Because I'll probably get it wrong because all I can think of is The Last of Us Right now.

And you you mentioned the whole, like, does the does the parasitoid trick the sawfly or the caterpillar into making itself more well known?

I don't know, Ken.

What what do you what question?

I know there's a burning question on the on the tip of your helmet, Vader.

I say yes.

Speaking of the, I guess, behavior manipulation.

Mhmm.

The the Cordyceps, your your last of us, and and all that.

Yep.

Yep.

That that's a great example.

Obviously, I could talk about parasitoids for several hours.

We could just make parasitoid podcasts, and I'd never stop talking.

But let's not do that.

So I the the cordyceps, we're still living in the insect world as far as what is being manipulated.

But we are firmly leaving it because, of course, the cordyceps group, if you will, are fungi.

And, you know, I often think about fungus as being really alien.

Right?

Like, so many different types of fungi, so many like, what they look like just looks alien and not of this world often.

And so what I'm actually gonna talk about is it's not Cordyceps group.

And obviously, as Ken mentioned, you know, the last of us people think about that word.

The one that I'm gonna talk about is actually Ophiocordyceps.

So it's a different genus.

And that is the fungus that causes zombie ants, for lack of a better way to describe that.

And I think it's kind of a perfect way to describe it.

And I should mention that, you know, we think about zombie ants, and that's the thing that comes to mind.

But, of course, lots of insects fall prey to things within the cordyceps group, crickets, grasshoppers, a bunch of true bugs, different things that fall prey to this.

But the ants are sort of the ones that have, like, the striking behavioral changes.

And one thing that the big example that I found is what's called a death grip.

So the ants in this case will after, you know, they go about their normal life, but right before they die, the ophiocordyceps will make them go to a certain spot and death grip on something.

So they're stuck there.

And depending on the species of ants and the species of the fungus, this can be leaves, bark, twigs, stems, but it's very specific.

So a a specific fungus will make a specific ant do it's not gonna be like, well, maybe it'll make it go on the leaf this time and the twig this time.

No.

No.

No.

Really specific.

And the one that I wanted to use, the case that I think is really interesting is Camponotus ants and Ophiocordyceps unilateralis.

I won't say that again, but that's the species.

So the fungus actually manipulates them not just going on the leaves.

So it's not just like, oh, I'm gonna go on the leaves anywhere.

It's specifically underside of leaves, northern side of saplings, about 25 centimeters above the ground.

The reason it does this is because that right there is the ideal conditions for that that fungus to grow.

So the fungus not only manipulates it to death grip on a leaf, but it's like, well, you're gonna death grip on a leaf.

You need to be on the north side.

You need to be 25 centimeters up.

And when experimental manipulation has moved it, the fungus doesn't grow as well.

So and if you let it be, it will make them go to these spots all over the forest floor.

And so, of course, the ant would look normal at this point as its death gripped onto the leaf.

And then, of course, after it dies, then that spore dispersal structure, which isn't always a mushroom, that's a specific word for fungus, but, you know, you can sort of think of it that way, pops out from behind the ant's head.

And it has to be in this spot.

And I think the spores coming out and the various insects that are infected by all these things in this cordyceps group, this is what people think about.

One other fun fact on cordyceps is apparently in areas where people eat cicadas a lot more than we do, not just in these seventeen year cicadas, but people who will dig up cicadas and eat them regularly, A bunch of people were getting sick because people were digging up the cicadas, and they had you could actually see it above the ground.

You could see those spore producing things popping out.

They dig up the cicadas, and they were like, well, I don't wanna eat that.

I don't know what that is.

So they take the outside part off and then eat the cicada, and then they were getting sick from corcepts because you they that species, humans can't eat it.

It will make us sick.

And so it's essentially like eating a poison mushroom, only it was a poison cicada.

And I believe these were occurring in China.

That's not here.

But if you're gonna eat your cicadas, I don't think we have that one here.

If you're gonna go to China and eat cicadas, be very careful that they don't have fungus growing out of

That's good to know.

Ken, you did, preselect our cicadas, didn't you, that we ate last year?

None of

us got cordyceps.

We're all fine.

Yay.

You promise none of us

are gonna turn into we haven't yet.

So I don't know.

Feel like it would be to climb a tree.

Though.

No?

Yes?

No.

I just have this urge to go somewhere.

I need a death grip on a leaf.

No.

We don't have those here.

Like I said, that's in China.

We don't even have I don't think we even have those corocept species here at all.

And those are those were, you know, their yearly cicadas.

Obviously, they don't have periodicals.

But I thought it was really interesting that, you know, this is something that can affect humans only so much as it will make us sick, not so much as it's like, we're not a host.

It's not like the last of us.

It can't go into our brains.

But it can make you sick like you have food poisoning but from eating bad cicadas.

And I I did want to mention just, again, we could talk about behavioral manipulation forever too, but there's just a couple more tiny examples, not of cordyceps, but of other parasites.

So one is there's something called a hairworm.

And when they infect crickets, they'll cause the crickets to go into the water so that the hairworm can then get to its next host.

Obviously, crickets are not swimmers, and they are not aquatic animals.

And then the other one that I thought was really interesting is there's little amphipods, which is little like shrimp like creatures in ponds.

And when they're infested with acanthocephalans, which are a parasitic worm, they live on sort of the bottom of the pond, and the worm will manipulate them into light seeking behavior.

So then they'll go up.

So they can be eaten by a duck, which is the next host for that particular worm.

So it goes up into where it's scary and they're gonna get eaten, and then they get eaten by ducks.

And so then the worm can carry on its life cycle to the detriment of the amphipod.

The snails are a big one too, aren't they?

They're huge ones.

Oh, yeah.

Yeah.

Lots and lots of snails are intermediate hosts for parasitoids or for parasites.

Absolutely.

Yep.

Yep.

I actually worked with a parasitologist in undergrad, and he studied turtle blood flukes, worms that live in turtle blood, and their intermediate host was snails.

So we'd have to go out to ponds and collect snails.

We put them in little cups and wait for them to shed the cercaria, which was the the life stage that was in the snails so then we could do, you know, stuff with them.

Not actually infecting turtles, as it turns out.

We weren't actually doing that part of it.

Oh, Ken, what a delightful topic.

Oh, yeah.

It really is.

I don't I don't know if I I thought snails were kinda cute.

Yeah.

Oh, they are, but they can shed cercaria and then, you know, go into turtles or all kinds of other things.

Don't don't eat them.

Fish.

No more escargot.

Yeah.

Yeah.

Maybe that's alright.

Maybe that's alright to give up.

Yeah.

Do your farm desk cargo.

Don't go wild caught.

Yes.

Don't go to a pond and just collect snails and eat them.

Not a good idea.

Just don't do that.

K.

Good to know.

I I do not wanna turn out like the guy on alien with, yeah, the

No.

No.

No.

Yeah.

No.

You don't want blood flukes either.

They won't chest burst, but you probably don't want those either.

Oh, no.

But still, uh-oh, I got a blood fluke.

It's not good.

It

sound it sounds like a whoopsie doopsie kind of like, oh, oopsie.

Yes.

A blood fluke.

Is a very silly name for things that cause so much destruction.

Yes.

Oh my gosh.

Your your your sausage there and your your trichinosis.

Oh my.

Oh.

Well, yeah.

All the way.

And it got a little cold.

I hope I'm alright.

Yeah.

We'll see.

As long as you cooked it before.

Maybe don't eat raw sausage.

Well, well, that that that was that was fun.

That we we have dove headfirst into some crazy, like, parasite, parasitoid lifestyles and activities.

I I don't think people are gonna be able to look at the world the same again after listening to this episode.

I'm okay with that.

I think, you know, you you hopefully, you will look at the world differently, not, like, in terror, but just that there's crazy cool life cycles all around you you maybe weren't aware of.

Because, again, these things that we've been talking about primarily are not gonna attack attack humans at all.

They're just really bad for the bugs.

Well, you know, we we did have some parasitic plants on the docket today, but, I mean, that's like going back to Care Bear Land, I feel like.

So I Ken, you still wanna talk about these?

Well, we need the palate cleanser.

Oh, okay.

Yeah.

We do need a palate cleanser.

Yeah.

So I think we we we put we have two on our notes here, but there Mhmm.

There's many more.

And these are well, I guess one's a a hemiparasite, and that'd mistletoe.

We did was that a year or two ago?

When do we do that?

We did have a whole episode on mistletoe.

Yeah.

We a very in-depth episode on mistletoe.

Yes.

Yeah.

Just, I guess, a quick recap, and we could put a note a link in the the show notes if you really wanna do a deep dive.

I don't know about a deep dive, but learn more.

It's probably surface surface level deep dive

for you.

Five foot five foot pool.

That's right.

Just in the shallow end.

No diving.

No diving.

No.

Dip your toes into it.

So with mistletoe birds so this is growing in, you know, trees.

So sometimes birds are gonna eat the berries.

Birds will do what birds do and deposit them all over the place.

So mistletoe was was dung on a stick.

Mhmm.

It was old English or would actually come from Saxon or or whatever.

But that's the the translation of it.

It be dung on a twig.

So the the plants the the seeds are deposited on on branches and trees and stuff.

The the seeds will germinate, will grow into the the branches of the trees, and they will take up water, sugars, stuff.

But the the plants are still producing leaves.

They're still photosynthesizing, so they're not getting all of their their energy and stuff from the plants.

They're they're they're hemiparasite because they can still photosynthesize on their own.

One that is a a true parasite is gonna be Dotter.

And if you're not familiar with Dotter, it looks like somebody just threw a bunch of spaghetti on a plant.

It's just kind of these long, thin, yellow strands of stuff.

And it's not I don't know if I've ever seen it in Illinois.

When I was in Florida, we'd see it every once in while.

But we do have it in the Midwest.

It's not a terribly common plant.

But this is an annual plant, so it's gonna produce seeds as well.

Those seeds are gonna be on the ground.

They're really big, you know, full of nutrients.

So because if these plants don't attach to a host, they're gonna die.

So they will attach their toast and they're kinda binding, and it will wrap around stuff, and they'll send out, which is basically the structure they're using.

They'll get into the the the camp the vascular system of the plants, and they will get all of their water, their nutrients, and stuff from those plants.

I I just used some references.

They may have some, like, leaf scales, but they're not photosynthesizing.

These are kinda oranges plants.

Everything is coming from that host.

They will flower, produce seeds, and then fall off.

So if you've got, like, a single daughter plant, you're probably not gonna see it.

It's when you get a bunch of plants.

You get this tangled mess of spaghetti, more or less, on your plants.

So they're out there.

And, you know, with these, with daughter and stuff, they can be crop pests.

Some areas can reduce the yield on plants.

And and if you've got them on, you know, ornamental plants, it's gonna you know, they're stealing nutrients and energy and stuff from the plants.

So you're gonna have a less vigorous plants, and it'll potentially stress the plants.

Stressed plants are more prone to attack from diseases and insects, stuff like that.

So and if you have it, you can try pulling it off.

And so I'd I don't think herbicide wise, I don't I'm not sure there's much you can do there because whatever you spray on, they're probably gonna get into the host plant too.

So and I think some of them can be fairly somewhat specific.

I think there's, like, a clover dotter or something like that.

There's multiple all kinds of different species out there.

I did not go down deep enough to wrap or the rabbit hole deep enough to to get into all of that, though.

That may be enough of the show for another day.

That's still pretty good.

I I have seen this in Illinois.

I think at least I've been sent pictures of this plant from people that I'm fairly certain in Illinois.

They're they're a master naturalist that we that I that is local here.

So she had sent pictures like, what is this?

And I like your spaghetti all over the place here.

I'm like, oh, yeah.

That looks like a parasitic plant known as daughter.

Yes.

Yeah.

So you're probably more likely to run into it in natural areas than you would a Mhmm.

Managed landscape.

Yeah.

Yeah.

I think it was in a prairie.

That's where she had had encountered it.

I have never heard of that, so I learned something today.

I need I need to take my knowledge of parasites into more into the plant world as well.

I I don't know.

We might have just hit them all.

They're right there, at least for Illinois or the this part of the world sorta.

Yeah.

There might be a few more.

Witchweed straga is another one.

I know that's in Africa, and there's some other hemiparasites.

Yeah.

And just not a lot that are would be considered true, true parasites, I suppose, in the plant world.

Because as you mentioned, a lot of these can photosynthesize at least a little.

Mhmm.

Yeah.

Yeah.

That handy.

Yeah.

Yeah.

Whereas our other parasites, you know, fully rely on their host to to get all their nutrients.

Well,

that was a lot of great information about parasites, parasitoids.

Hopefully, by now, you you know the difference between the two.

I'd rather have a parasite than a parasitoid.

So I definitely have learned that part.

Watch out for cicadas.

You don't wanna eat the ones with the cordyceps.

Or or are fuzzy butts?

Is it like a is that the one with the that that sounded wrong.

Cut that out, Ken.

No.

Leave it in.

No.

Well, they they have the they'll have the fruiting bodies coming out of them.

Okay.

Yep.

And so and again, I don't think we have that here.

You go to China, maybe don't need to scale.

Oh, man.

Alright.

Well, the Good Growing podcast is a production of University of Illinois Extension, edited this week by Ken Johnson.

My career is in your hands, Ken.

Oh, doctor Kacie Athey, thank you so much for being here today.

I we we I think that that was a very good dive and swim through the world of parasites.

So I really enjoyed that.

Thank you so much.

Thank you for having me.

Right.

And, Ken, thank you for for editing and being here.

Once again, I appreciate you.

Thanks for that.

I I I love the the Mothman costume.

I love the Darth Vader.

So happy Halloween, everyone.

Yeah.

Happy Halloween.

I I won't channel my hat on Darth Vader.

I'll I can't do this by myself, so I'm not gonna

I can be Palpatine.

She's influencing you.

And, yes, thank you, Kacie.

And, Chris, let's do this again next week.

Oh, we shall do this again next week.

We're gonna be getting in November, and I don't have a beard anymore.

It's cold.

My face is cold.

And so, yeah, we're we will get back into the horticulture hijinks as the season has, I think, the doors, you know, pretty much shut on us for right now.

So we'll get into a topic Guardian topic next week.

Well, listeners, thank you for doing what you do best, and that is listening.

Or if you watched us on YouTube, watch it.

And as always, keep on growing.

Flying around about the time that those caterpillars are, yeah, about halfway their the size that they're gonna be.

Although they can attack at at

different times.

Itka.

And she'll go around.

Itka.

And a lot of parasitoids Bears.

Aren't attracted to their Bears.

So it's not the cat

Bears.

Parasitoid is like

Polish sausage.

Polish sausage.

Polish sausage.

Okay.

I don't know if that's Chicago.

If not, just, like, Northern Minnesota.