Ep. 230 From alien wasps to zombie ants, parasites are all around | #GoodGrowing - Good Growing

Episode Transcript
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Chris Enroth (00:04):
Welcome to the Good Growing podcast. I am Chris
Imra, vorticulture educator withUniversity of Illinois Extension
coming at you from Macomb,Illinois. Now today, it is the
spooky episode, and you notice Isound a little bit different. I
also look a little bitdifferent. That's because I, if

(00:26):
you're listening, am a bearssuper fan.
I've got my bears gear on. I gotmy my bears hat on, and I am,
saluting as always to the, the,you know, almost patron saint,
Ditka. He's almost there. Heneeds one more miracle. He's
gonna get there, though.
So alright. And today, we aretalking parasites. Now

(00:50):
parasites, that's gonna be somuch fun. We're gonna be
speaking with doctor KacieAthey, but this is beyond me. So
I definitely need help todaybecause all I can do is maintain
this very poor Chicago accent.
So I am joined as always everysingle week by horticulture
educator Ken Johnson inJacksonville. Oh my gosh. Hello,

(01:14):
Ken. I may the force not be withyou. You're the bad one.
Go ahead, Ken.

Ken Johnson (01:20):
Hello, Chris. I'm not gonna I'm not gonna try the
voice because I can't I can'ttop you. So

You're not gonna do the voice? I wish Darth Vader
had a giant orange beard pokingout 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 onYouTube and see it here, folks.
Darth Vader with a beard. I lovethis.

Yeah. I'm not sure how long this mask is gonna stay
on because my glasses arealready 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, areare 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 alsoyou know, I have my mug of of of
of cold draft here, which istechnically just, apple juice,
but, you know, gotta haveappearances. I also have my
Polish sausage. Let me get thisthing ready.
I will be eating and drinkingthroughout this event here that

(02:36):
we have going on. So we hadbetter we had better get
started. Right, Ken?

Exactly.

Alright. Excellent. Well, I am so happy
to welcome all the way from theChampaign Of Urbana. Welcome,
doctor Kacie Athey, to the GoodGrowing podcast broadcast here
in in Illinois. Hey, doctorAthey.
How are doing?

Kacie Athey (03:02):
I'm good. Thank you. Thanks for having me.

Now,can you explain your costume to us,
please? Because this is I I lovethis costume. It is a very good
one.

Yes. So it is not emperor Palpatine, even though
it kinda looks that way. I amthe mothman or mothwoman, I
suppose, in this particularcase. And you can't see all of
it, but but, yes, I'm themothman, which seemed
appropriate since I'm anentomologist.

It it is an excellent urban legend, Mothman.
I don't know. Well, I have toask you. Do you believe in the
Mothman?

I don't know. Okay. I'm not sure that I believe
encrypted so much as I justreally like the stories, and I
promise not to haunt bridges ormake them fall down.

Of the few things I know about Mothman, it is from
the movie, The Mothman. And thenthe I remember bridges being a
pivotal role in that movie. It'slike all bridges.

Yes. For some reason, the Mothman really wants
to get rid of bridges. Yeah. I'msure people who are really into
cryptids probably have a muchbetter explanation than I do.

Because space space moth, you know, maybe
something like that. I don'tknow. They just anti bridge.
Yes.

Yes.

Mhmm.

Yeah.

Well, Kacie, we are so happy to have you on
today, and we're talkingparasites. And so I guess we
should dive into this. Ken,would you mind kicking us off,
please, before my my Polishsausage 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 howare they different than
diseases, or are they basicallythe same?

Well, so, yeah, parasites kind of you could
separate parasites and diseasesfrom each other a little bit. So
a parasite would cause adisease, right, in a person. But
parasites live on or in a hostorganism, and they feed off of
them, which is a little bitdifferent than bacteria and
viruses that aren't reallyfeeding off of the the host

(05:22):
organism. And generallyspeaking, the other thing about
parasites is we tend to think ofthem as not really killing their
host so much, although,certainly, that happens a fair
amount. And and, obviously,bacteria and viruses don't

(05:43):
always kill their host, but sortof a a hallmark of parasites
when we think about that istrying to keep the host alive
because they're actively feedingoff of that host.

That that's a really good distinction. I we as
we're doing a little researchfor 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 youexplain it. Because, like, yeah,
I guess a virus, it kindahijacks. It, like, takes over
stuff.
Yep. The parasite is is isliterally, 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 manyparasites out and around us. And
so, I don't know. It what wouldyou say would be the most common
parasite out there? Is there acommon parasite that humans
typically encounter?

Well so I suppose that's a hard question, but I
suppose we can think about sortof, like, the parasite that is
scare scariest for humans or hadthe most impact on humans writ
large. And so, of course, thethe most common one is malaria.
If you think about malaria,malaria is a parasite, and it

(06:57):
the fact that malaria existsactually makes mosquitoes the
most dangerous animal on theplanet because they vector
malaria. And so let's see. In2023, I looked this up before
this.
There were two hundred and sixtythree million cases of malaria
worldwide, and almost sixhundred thousand people died

(07:18):
from malaria in 2023. And sothat is you know, we think of
malaria as a disease because itis, but it is caused by a
parasite that is then, you know,feeding off of the host, us, and
then also its other host, whichis mosquitoes. And the other
thing to keep in mind, I think,when we think about parasites is

(07:39):
that their life cycles can bereally complex. If you think
about a bacteria, a bacteria isgoing to infect someone, and it
doesn't need to move somewhereelse to complete its life cycle.
Like, it can enter a body and doall of its things right there,
nothing else necessary.
A lot of parasites, that's notthe case. So malaria, as an

(08:01):
example, needs a mosquito, andit needs a vertebrate of some
sort. And, of course, in thecase of the malaria that we talk
about, it's humans. But itcannot complete its life cycle
if it doesn't have both of thosethings. And so I think the
interest for me with parasiteshas always been that they are

(08:22):
complicated, that thinking aboutlife cycles like this and
thinking about how they persistand why, I suppose, was always
really interesting, especiallywith internal parasites.
We get that a little less withthings that are feeding on the
outside of an animal. So if youthink about, like, lice, right,
they don't have complex lifecycles. They can feed on the

(08:45):
same vertebrate, reproduce, doall their things. Really, a lot
of the complex ones are the onesthat end up inside bodies.

It's true. Well, speaking of the more external,
just yesterday, we were had amaster naturalist training, and
we are October yesterday wasOctober 23. We had dipped right
into to the freezing point, andI pulled a a black legged tick
off of me after the class. Sothere's they're still out. Yeah.

(09:14):
Yes. Even though it's coldoutside now.

Yes. Yeah. Yeah. And, I mean, we could talk for a
long time about ticks and thefact that there are more of them
and the fact that their rangesare expanding. You know?
So it's not as if externalparasitoids aren't also or
parasites aren't alsointeresting or, you know, to be
paid attention to. Mhmm. They'rejust their life cycles just tend

(09:38):
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 touncover 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. Youknow, say things. So the first
ones were kinda the theparasites we may encounter in
our garden for better or forworse, I guess. So or the

(10:17):
parasitoid wasps, the first onewe 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 inparasitoid wasps. I I worked in
a lab that we did naming of newspecies, classifying. And in
fact, fun fact, there is a waspthat is named after me.

(10:47):
A parasitoid wasp, which is fun.No. I don't know what it
parasitizes because it's basedon 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 thinkit'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 dolook like Palpatine if I'm not
careful. So I gotta gotta dosomething different. We can just
focus on the necklace that looksa little moth man y. So, yes,
I'm very interested inparasitoids.
And I should mention thatparasitoids are it's a different

(11:45):
word than parasite. Right? Andsort of the distinction here and
kind of the thing we generallytalk about is that parasitoids
always, pretty much always, killtheir hosts. There's no
surviving unless the host mountsa immune attack or some other
thing. If the parasitoid is a issuccessful and it gets to

(12:08):
adulthood, its host is gonnadie.
And so that's, you know, thereason why we're not just saying
parasite wasps because you don'tif you're attacked by a
parasitoid, you're not gonnasurvive that. And I also I'm
going to talk about wasps, but Ishould mention that parasitoids,
there are kind of a bunch ofgroups that contain them. So

(12:32):
there's lots of parasitoidflies, and those are going be
ones you're going to encounterin your garden as well. There
are parasitoid moths. There's athere's a whole family of of
moths that attack leafhoppersand things like that.
And then there's other sort ofweirdos and other families. So
parasitoid moths. There'ssomething called twisted wing

(12:54):
parasites, but those trend moretowards actually parasites.
Caddisflies, if any of theaudience knows what a caddisfly
is, there's a few of those thatare parasitoids. And then things
related to lacewings.
So members of Neuropterans,there's some parasitoids in
there, and there's parasitoidbeetles too. So the group itself

(13:17):
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'slots of cool other stuff in the
other groups. And I would arguethey're some of the coolest

(13:39):
animals for a variety ofreasons.
They go after all kinds ofdifferent 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.

(14:00):
Some are not so simple, and someare implausible, if you will.
And so I also wanna mentionsomething. This is a Halloween
episode. So something thatentomologists talk about a lot
is that these are chest bursterfrom alien. Right?
Everybody knows what that is.That's a parasitoid. That's what

(14:23):
that is. It's not a parasitebecause you're not gonna live
through it. And the when the thealien pops out, that is not all
that different from a parasitoidemerging from a thing that it's
not supposed to be in.
And the other thing that in myexperience with parasitoids,

(14:48):
there's a lot of people who arebutterfly collectors. And the
absolute worst thing thathappens to these people, they've
got their caterpillars andthey're rearing them. They're
feeding them leaves, hoping toget some special butterfly out,
and then they either get a flyor a wasp. And I got to give a
talk to a group of these peopleonce, and my talk was all about
parasitoids, and I think Ihorrified them. They were not

(15:11):
amused.
They did not like it because Iwas like, look at all these cool
caterpillars, and look at allthe cool wasps that came out.
They were not having a goodtime. I was. And so, you know,
sort of bursts all their hopeswhen it's like, here's a cool
wasp that popped out, not thebutterfly 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 itshould have been for me, to be
honest. I'm sorry, KentuckyLepidopter Society.

I I I've been there. I've reared a few monarch
caterpillars with my kids, andthen all of a sudden from the as
it forms its chrysalis, it turnsnot the right color, very dark,
gooey looking color. And thenthese little maggoty looking
things start dropping like, youknow, special forces from a

(16:11):
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 ofpeople of course, people want
their monarchs. But one thing tothink about is if you have a
parasitoid that specializes onmonarchs, although we all think
monarchs are really, really coolbecause they are, that
specialist parasitoid is also aunique animal that, you know,

(16:47):
needs the monarch to survive.And so without monarchs, we also
wouldn't have that weirdo that'scoming out of your monarchs. So,
you know, I like to think of itthat, generally speaking, if you
have, you know, nativeparasitoids and native hosts,
you're generally not gonna haveso many of them that the

(17:08):
parasitoid is gonna wipe out thehost because then the
parasitoid, if it's aspecialist, doesn't have
anywhere else to go.
So it behooves them not to dothat. And I kind of thought that
the next place to go when I'mtalking about parasitoids is to

(17:29):
talk about a parasitoid thatprobably everybody has seen
before, whether or not you knowthat's what it is. So let's
think about our gardens. And forpeople who grow tomatoes
especially, you'll think aboutthe giant giant caterpillar with

(17:50):
the hornworm on the the horn onthe back that is gonna be eating
your tomatoes a little bit everyyear. And at some point in the
year, at least one of those onyour tomatoes is going to sprout
a bunch of white things out ofthe back of it.
I've heard people say that theseare eggs. I've heard a lot of
different interpretations ofthat. Those are parasitoid

(18:11):
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 aroundabout the time that those

(18:32):
caterpillars are about halfwaythe size that they're going to
be, although they can attack atdifferent times.
And she'll go around. And a lotof parasitoids actually aren't
attracted to their hosts. Soit's not the caterpillar that
the parasitoid is, like, cluingin on. It's actually the plant.

(18:56):
So as the caterpillar chomps onthe plant, it's releasing
chemicals that the parasitoid isactually queuing in on first.
And then the parasitoid will goand find its host as a result of
that. So she's gonna get there,and she's gonna lay eggs inside
that caterpillar. Someparasitoids lay one egg inside
each host. So we have a lot ofparasitoids of eggs, squash bug

(19:21):
eggs, stink bug eggs. They'regonna lay one egg inside of that
egg because it can't handleanything else.
A tobacco hornworm can handle awhole lot more than that. So any
given female is gonna lay just abunch of eggs inside that
caterpillar. The caterpillardoes have some defenses. So a
caterpillar can move around alot. They can vomit in the

(19:46):
general direction of theparasitoid.
They can poop in the generaldirection of the parasitoid. So
a lot of times, the parasitoidswill actually attack, like,
behind their head because it'sthe hardest place for them to
get to. So then she lays hereggs, and they'll hatch in
there, and they'll start feedingon that caterpillar inside. Now

(20:07):
I found a thing that wasactually really, really
interesting. There was one Ifound a study, and there was one
tobacco hornworm that had 816 ofthese Cotesia larvae inside of
it, inside of one, which I can'teven fathom how that works.
816. Now that wouldn't have beenfrom one female. Right? So a

(20:31):
wasp comes and does it. Maybeanother wasp comes on and is
like, looks like a goodcaterpillar.
I'll lay my eggs in that too.The maximum number that could
actually come out was 200. Sothink about a tobacco hornworm
with those little white cocoonson the outside, and think about
one being covered in 200 of themand those things surviving. And

(20:53):
so large numbers here with thesecaterpillars. And it's I think
it's really impressive that theyhad enough to eat at all to
survive for 200 of them to comeout.
And so one other thing is withthese parasitoids, they don't

(21:15):
actually affect what the hormonedoes for most of the time that
they're in there. So someparasitoids can make a
caterpillar or their host eatmore, can make it eat less, can
make it behave a little bitdifferently depending on what
will be beneficial to them. Inthe case of the tobacco
hornworm, those Cotesia waspsinside there aren't making it do

(21:39):
anything. It's just eaten. It'sdoing its thing.
They do stop it eating once theyspin those cocoons and come out.
So when you see that hornworm inyour garden and it's got all
those cocoons on its back, allof the white things, it's no
longer eating because theparasitoids have stopped it from
doing that at this point. And Idon't think there's a concrete

(22:01):
reason for that, but there'ssome evidence that unparasitized
tobacco hornworms will eatCotesia cocoons. And so there's
some thought that maybe theparasitoid stops them from
eating so the caterpillardoesn't go, hey. What are these?

(22:21):
I could eat these. So it's notgonna eat at all, So then it
isn't gonna eat the cocoons allover its body, possibly. That's
a hypothesis anyway. But we theydo know it has been observed
that the unparasitized ones willgo around and eat. Like, if they
fall off, sometimes they'll falloff and the caterpillars will
eat them.

Interesting.

Yeah. One thing one little digression with insects
is we often talk about thingsthat are like caterpillars or
herbivores. Right? You know, allcaterpillars. Well, most.
But if there's something easy toeat that's full of protein,
things are gonna chomp thatdown, whether it's like a pupa
in front of you that's easy toeat or an egg or something like

(23:04):
that. So that's not out of therealm of of possibilities as my
aside. So that's kind of thatkinda wraps up those guys as far
as what you will normally seepretty predominantly in your

(23:26):
gardens for parasitoids. I willmention one more garden
parasitoid. If you have aphidsin your garden, you probably
have parasitoids.
So aphids, if you ever see themwhere they look like they're
kind of now made of paper andthey're ballooned up, that's
evidence of a wasp that got inthere and attacked them. And so

(23:50):
when you're in your garden, ifyou're just paying a little bit
more attention, you can actuallysee evidence of parasitoids
probably every year, at leastthose two for sure. If not some
other interesting things, butthose are the most predominant
ones, I would say, in the gardenparasitized wise. A

fun one is just to look at milkweed or I have some
tulip poplars also. They alwayshave aphids on them. And just
look under the leaves, look onthem, and you see you could use,
like, a hand lens or somethinggoing real close. That wasp cuts
a tiny little hole out the theback end of that aphid, and it

(24:34):
just bursts out just like justlike an alien. So Yep.
Yeah.

And it does look like somebody blew up the aphid
like a balloon and then made itout of paper mache. Mhmm. It
it's it's really it's reallywild. And fun fact, that's not
just, like, one species. Itseems like things that
parasitize aphids, which are notvery closely related, the the
two groups that do it, they allmake the aphids do that even

(25:02):
though they're not related toeach other, which is kind of
interesting.
There's not a different way ofparasitizing, even though
they're very un two veryunrelated 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 aboutis technically probably in
gardens. It's probably mostplaces. It's just not very

(25:52):
commonly encountered or thoughtabout, I would say.
And the reason I wanted to talkabout it is because its life
cycles are so implausible. Sowhereas the tobacco hornworm,
that, again, that wasp justneeds to find a tobacco
hornworm. And she can lay hereggs directly in there, and she

(26:13):
can walk away, and she can feellike, yep. I got it. I've I've
done my job.
My babies are where they'resupposed to be, giving them the
best chance. And sometimesthat's not how it works. So
sometimes it's complicated thatsimple, I'm just gonna lay my

(26:35):
eggs inside this thing, bestchance to exist. Sometimes it's
complicated because of somethingcalled hyperparasitoids. So
hyperparasitoids are parasitoidsof parasitoids.
So if I'm gonna go back to thetobacco wormworm example, when
those cocoons come out, there'sanother wasp that comes out and

(26:56):
goes, Now that's my host, andgoes and legs her lays her egg
inside that cocoon. So theninstead of getting Cotesia out
of there, you get somethingelse. Some other wasp pops out
because its host is not thetobacco hornworm. Its host is
actually Cotesia. So that's morecomplicated.
Now that one would be easier forwasp mom. Right? Because wasp

(27:19):
mom can literally see those.What if she's going after a the
Cotesia that's inside? So nowshe has to find a hornworm
that's not outside visiblyparasitized, but she's gotta get
her eggs inside of there, andthen her babies have to find
their host inside thecaterpillar.

(27:39):
Little more complicated.Although with Cotesia and the
hornworms, there are cues againthat the plants giving off the
tobacco hornworm actually hascues she can pick up on that she
knows that is parasitized. Soshe's not she's not going in
blind. She's not just laying hereggs in a thing and hoping that

(28:00):
the host is actually in there.And so it's cool.
It's complicated, but itactually sounds pretty
plausible. Again, it's justusing cues with the environment,
knowing that that's inside ofthere. A lot of parasitoids
attack things that are hidden,things in wood, and so the mom
has to do something to know thather host is in fact in there,

(28:20):
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 wanther babies to live. Not true,

(28:45):
but it seems like that.
So, again, these probably are attimes in your gardens, near your
houses, but they are definitelyfound more commonly in forest
systems or, like, more wildsystems, I think, when we
actually find them. So I Iactually have two examples for

(29:07):
trigonalids, both complicated indifferent ways. But I want to
start with I've been talkingabout how parasites generally
are laying their eggs directlyon their host or in their host.
Right? Easiest way to do it.
Trigonads do not do that. Theylay their eggs on leaves, and
they lay thousands of them onleaves. And they lay them pretty

(29:30):
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 theparasitoid flies will lay their
eggs on leaves because they haveto be eaten.
That's how they have to get inthe body of their host. But the
tachinid mom will lay her eggsnear a host. She'll be like,

(29:53):
well, the eggs should go herebecause the host is right here,
so it's tricky and old momsdon't do that. They're just
like, well, this is a leaf. Thiswill be fine.
I'll just throw some over there.And truly, there's never been
any evidence that they lay themanywhere near potential hosts.
They don't do that. They justlay them. So I I like to think,

(30:15):
you know, it's sort of willynilly.
They just lay some, go to thenext 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'rejust there. And by chance, a
caterpillar or a soft fly needsto eat them. So okay.
Sure. That's actually, again,not that complicated. Cool. And
it does it does seem simple atthis point, except that's not

(30:50):
the host. That's not the hostfor the trigonalid.
Not yet, anyway. Their host is aichneumonid wasp or a tachinid
fly, depending on the species,that's already inside of that
caterpillar or sawfly. Andremember, it's willy nilly. So
it's not like the mom put itnear a parasitized already

(31:11):
parasitized thing. That thingcould have nothing in it.
So the trigonalidae could end upinside of the proper
caterpillar, but there's noEchneumonid in there, so game
over. Now if it is, then theyyay. They get to go feed off of
that ichneumonid or tachinid.Okay. Great.

(31:33):
So that part has happened. Thenwhen that thing pupates inside
well, now they actually do haveto eat the sawfly or the
caterpillar. So then they haveto go out of the sawfly or the
caterpillar and then feed on theoutside of that and consume
that. So they can't just eatwhat we thought was their
primary host. They then have toeat the secondary host, and then

(31:56):
that's how that one ends.
Complicated and seeminglyimplausible, especially if
they're more specific, you know,if it has to be a certain
species. Now, of course, thefact that she lays thousands of
eggs is probably the reason whywe've ever heard of these
animals at all. But that one'sactually less complicated, I

(32:18):
think. So the other one is thesame. So it's all the same.
Just willy nilly eggs.Caterpillar or softly has to eat
it, and then something like apaper wasp has to come along and
take that softly or thatcaterpillar to feed its babies
with that softly or thecaterpillar. Because the actual
host for the trigonalid is thebaby paper wasp, not the softly

(32:44):
or the caterpillar. So then sothen 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 thenest, and it can either get in
by being eaten by the baby paperwasp and then exiting the gut

(33:05):
there and then you know?
Or if the the the paper wasp momchews up the caterpillar and
baby birds it, it can also do itthat way. It can also get in but
it has to get into the paperwasp larva because that is its
host. And so then it can, youknow, do its thing and feed on

(33:28):
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 thecaterpillar, but if a paper wasp
or something doesn't come andtake you and take you to its
baby, you then don't surviveeither.
So just implausible life cyclesthat just do not make any sense

(33:53):
but have persisted, again,because all she does is lay so
many eggs in the environmentthat by chance, a couple of
those are gonna become adultsagain. So just the wildest life
cycle and one of my favoritestories.

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 aa few things you could cut out
there and and be more efficientin your energy. And, yeah, it I
feel like there's may maybe it'sin the process of
specialization.
I don't know.

Well and if you think about some things, so like
I mentioned with tobaccohornworms, the parasitoids
trying to attack those directly,often there is antagonistic
interactions. Right? Becausethese hosts aren't just
helpless. They have ways offighting back. And so if you're
going directly after something,you stand the chance of being

(34:51):
injured, you stand the chance ofa variety of things.
If you are just throwing eggsinto the environment, you
yourself don't don't have thoseantagonistic interactions. And
so maybe there's something tothat as well where it's a
different type of strategy.Like, well, I'll just put
instead of putting my energyinto fighting this thing, I'm
gonna put my energy intoproducing absurd amounts of eggs

(35:14):
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 thatalter the caterpillar or sow
fly's behavior to, like, makethem 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 thatis known. It probably is. I just
you know, a lot of the papersthat I was looking at and what I
was doing would focus so much onthe weird life cycle part that
they don't talk as much about,like, the actual behavior of,

(35:49):
like, the soft lye or thecaterpillar as far as, yeah,
whether it's putting itself outin the open so it gets taken
away by a paper wasp or thingslike that, which it absolutely
could be. I mean, the behavioralmanipulation, again, even with
the hornworm, it's so much as,like, we're just not gonna eat.
There there there's definitelythat possibility that it does

(36:14):
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 ahornworm this year that had all
of the the cocoons on it, And Isaw now now after hearing you,
Kacie, I saw all these tinywasps on there. But I I remember
watching a video many years ago,like, when when the hornworm

(36:40):
parasitoid, when that comes out,it cuts a little hole in the top
of the cocoon. I remembersaying, I didn't see any holes
in the tops of the cocoons, butthere'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 afteris usually smaller. And so if
you see something really littleon 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 Ifeel like there are a few, like,
hyperparastoids ofhyperparasitoids as well.

(37:23):
But, you know, that that's

The Russian nesting doll situation here. I I
think what about there there'sanother, though. I don't know,
Ken. Can you wanna ask thisquestion? Because I'll probably
get it wrong because all I canthink of is The Last of Us Right
now. And you you mentioned thewhole, like, does the does the

(37:49):
parasitoid trick the sawfly orthe caterpillar into making
itself more well known?
I don't know, Ken. What what doyou what question? I know
there's a burning question onthe on the tip of your helmet,
Vader.

I say yes. Speaking of the, I guess, behavior
manipulation. Mhmm. The theCordyceps, your your last of us,
and and all that.

Yep. Yep. That that's a great example.
Obviously, I could talk aboutparasitoids for several hours.
We could just make parasitoidpodcasts, and I'd never stop
talking.
But let's not do that. So I thethe cordyceps, we're still
living in the insect world asfar as what is being

(38:33):
manipulated. But we are firmlyleaving it because, of course,
the cordyceps group, if youwill, are fungi. And, you know,
I often think about fungus asbeing really alien. Right?
Like, so many different types offungi, so many like, what they
look like just looks alien andnot of this world often. And so

(38:59):
what I'm actually gonna talkabout is it's not Cordyceps
group. And obviously, as Kenmentioned, you know, the last of
us people think about that word.The one that I'm gonna talk
about is actuallyOphiocordyceps. So it's a
different genus.
And that is the fungus thatcauses zombie ants, for lack of

(39:23):
a better way to describe that.And I think it's kind of a
perfect way to describe it. AndI should mention that, you know,
we think about zombie ants, andthat's the thing that comes to
mind. But, of course, lots ofinsects fall prey to things
within the cordyceps group,crickets, grasshoppers, a bunch
of true bugs, different thingsthat fall prey to this. But the

(39:45):
ants are sort of the ones thathave, like, the striking
behavioral changes.
And one thing that the bigexample that I found is what's
called a death grip. So the antsin this case will after, you

(40:09):
know, they go about their normallife, but right before they die,
the ophiocordyceps will makethem go to a certain spot and
death grip on something. Sothey're stuck there. And
depending on the species of antsand the species of the fungus,
this can be leaves, bark, twigs,stems, but it's very specific.

(40:33):
So a a specific fungus will makea specific ant do it's not gonna
be like, well, maybe it'll makeit go on the leaf this time and
the twig this time.
No. No. No. Really specific. Andthe one that I wanted to use,
the case that I think is reallyinteresting is Camponotus ants
and Ophiocordyceps unilateralis.

(40:56):
I won't say that again, butthat's the species. So the
fungus actually manipulates themnot just going on the leaves. So
it's not just like, oh, I'mgonna go on the leaves anywhere.
It's specifically underside ofleaves, northern side of
saplings, about 25 centimetersabove the ground. The reason it

(41:18):
does this is because that rightthere is the ideal conditions
for that that fungus to grow.
So the fungus not onlymanipulates 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 thenorth side. You need to be 25
centimeters up. And whenexperimental manipulation has
moved it, the fungus doesn'tgrow as well. So and if you let

(41:43):
it be, it will make them go tothese spots all over the forest
floor.
And so, of course, the ant wouldlook normal at this point as its
death gripped onto the leaf. Andthen, of course, after it dies,
then that spore dispersalstructure, which isn't always a
mushroom, that's a specific wordfor fungus, but, you know, you

(42:07):
can sort of think of it thatway, pops out from behind the
ant's head. And it has to be inthis spot. And I think the
spores coming out and thevarious insects that are
infected by all these things inthis cordyceps group, this is
what people think about. Oneother fun fact on cordyceps is
apparently in areas where peopleeat cicadas a lot more than we

(42:30):
do, not just in these seventeenyear cicadas, but people who
will dig up cicadas and eat themregularly, A bunch of people
were getting sick because peoplewere digging up the cicadas, and
they had you could actually seeit above the ground.
You could see those sporeproducing things popping out.
They dig up the cicadas, andthey were like, well, I don't

(42:51):
wanna eat that. I don't knowwhat that is. So they take the
outside part off and then eatthe cicada, and then they were
getting sick from corceptsbecause you they that species,
humans can't eat it. It willmake us sick.
And so it's essentially likeeating a poison mushroom, only
it was a poison cicada. And Ibelieve these were occurring in
China. That's not here. But ifyou're gonna eat your cicadas, I

(43:14):
don't think we have that onehere. If you're gonna go to
China and eat cicadas, be verycareful that they don't have
fungus growing out of

That's good to know. Ken, you did, preselect
our cicadas, didn't you, that weate 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'sin China. We don't even have I
don't think we even have thosecorocept species here at all.
And those are those were, youknow, their yearly cicadas.
Obviously, they don't haveperiodicals. But I thought it
was really interesting that, youknow, this is something that can

(44:03):
affect humans only so much as itwill 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 likeyou have food poisoning but from
eating bad cicadas. And I I didwant to mention just, again, we

(44:28):
could talk about behavioralmanipulation forever too, but
there's just a couple more tinyexamples, not of cordyceps, but
of other parasites. So one isthere's something called a
hairworm. And when they infectcrickets, they'll cause the
crickets to go into the water sothat the hairworm can then get

(44:49):
to its next host. Obviously,crickets are not swimmers, and
they are not aquatic animals.
And then the other one that Ithought was really interesting
is there's little amphipods,which is little like shrimp like
creatures in ponds. And whenthey're infested with
acanthocephalans, which are aparasitic worm, they live on

(45:11):
sort of the bottom of the pond,and the worm will manipulate
them into light seekingbehavior. 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 upinto where it's scary and
they're gonna get eaten, andthen they get eaten by ducks.

(45:31):
And so then the worm can carryon 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 hostsfor parasitoids or for
parasites. Absolutely.
Yep. Yep. I actually worked witha parasitologist in undergrad,
and he studied turtle bloodflukes, worms that live in
turtle blood, and theirintermediate host was snails. So

(46:04):
we'd have to go out to ponds andcollect snails. We put them in
little cups and wait for them toshed the cercaria, which was the
the life stage that was in thesnails 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 allkinds 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. Justdon'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 probablydon'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 intosome crazy, like, parasite,
parasitoid lifestyles andactivities. I I don't think

(48:12):
people are gonna be able to lookat 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 theworld differently, not, like, in
terror, but just that there'scrazy cool life cycles all
around you you maybe weren'taware of. Because, again, these
things that we've been talkingabout primarily are not gonna
attack attack humans at all.They're just really bad for the

(48:37):
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 ahemiparasite, and that'd
mistletoe. We did was that ayear or two ago?
When do we do that? We did havea 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 thethe show notes if you really
wanna do a deep dive. I don'tknow about a deep dive, but
learn more. It's probablysurface 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. Birdswill do what birds do and
deposit them all over the place.So mistletoe was was dung on a
stick.
Mhmm. It was old English orwould actually come from Saxon

(50:10):
or or whatever. But that's thethe translation of it. It be
dung on a twig. So the theplants the the seeds are
deposited on on branches andtrees and stuff.
The the seeds will germinate,will grow into the the branches
of the trees, and they will takeup water, sugars, stuff. But the
the plants are still producingleaves. They're still
photosynthesizing, so they'renot getting all of their their

(50:33):
energy and stuff from theplants. They're they're they're
hemiparasite because they canstill photosynthesize on their
own. One that is a a trueparasite is gonna be Dotter.
And if you're not familiar withDotter, it looks like somebody
just threw a bunch of spaghettion a plant. It's just kind of
these long, thin, yellow strandsof stuff. And it's not I don't

(50:57):
know if I've ever seen it inIllinois. 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 commonplant. But this is an annual
plant, so it's gonna produceseeds as well. Those seeds are
gonna be on the ground. They'rereally big, you know, full of
nutrients. So because if theseplants don't attach to a host,
they're gonna die.
So they will attach their toastand they're kinda binding, and

(51:20):
it will wrap around stuff, andthey'll send out, which is
basically the structure they'reusing. They'll get into the the
the camp the vascular system ofthe plants, and they will get
all of their water, theirnutrients, and stuff from those
plants. I I just used somereferences. They may have some,
like, leaf scales, but they'renot photosynthesizing. These are
kinda oranges plants.

(51:41):
Everything is coming from thathost. They will flower, produce
seeds, and then fall off. So ifyou've got, like, a single
daughter plant, you're probablynot gonna see it. It's when you
get a bunch of plants. You getthis tangled mess of spaghetti,
more or less, on your plants.
So they're out there. And, youknow, with these, with daughter
and stuff, they can be croppests. Some areas can reduce the

(52:04):
yield on plants. And and ifyou've got them on, you know,
ornamental plants, it's gonnayou know, they're stealing
nutrients and energy and stufffrom the plants. So you're gonna
have a less vigorous plants, andit'll potentially stress the
plants.
Stressed plants are more proneto attack from diseases and
insects, stuff like that. So andif you have it, you can try

(52:26):
pulling it off. And so I'd Idon't think herbicide wise, I
don't I'm not sure there's muchyou can do there because
whatever you spray on, they'reprobably gonna get into the host
plant too. So and I think someof them can be fairly somewhat
specific. I think there's, like,a clover dotter or something
like that.
There's multiple all kinds ofdifferent species out there. I

(52:48):
did not go down deep enough towrap or the rabbit hole deep
enough to to get into all ofthat, 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 leastI've been sent pictures of this
plant from people that I'mfairly certain in Illinois.
They're they're a masternaturalist that we that I that
is local here. So she had sentpictures like, what is this?
And I like your spaghetti allover the place here. I'm like,
oh, yeah. That looks like aparasitic plant known as

(53:17):
daughter. Yes.

Yeah. So you're probably more likely to run into
it in natural areas than youwould a Mhmm. Managed landscape.

Yeah. Yeah. I think it was in a prairie.
That's where she had hadencountered it.

I have never heard of that, so I learned something
today. I need I need to take myknowledge 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 leastfor Illinois or the this part of
the world sorta. Yeah. Theremight be a few more.

Witchweed straga is another one. I know that's in
Africa, and there's some otherhemiparasites.

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 lotof 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 toget 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 definitelyhave learned that part. Watch
out for cicadas.
You don't wanna eat the oneswith the cordyceps. Or or are
fuzzy butts? Is it like a isthat the one with the that that

(55:01):
sounded wrong. Cut that out,Ken.

No. Leave it in. No. Well, they they have the
they'll have the fruiting bodiescoming out of them.

Okay. Yep.

And so and again, I don't think we have that here.
You go to China, maybe don'tneed to scale.

Oh, man. Alright. Well, the Good Growing podcast
is a production of University ofIllinois Extension, edited this
week by Ken Johnson. My careeris in your hands, Ken. Oh,
doctor Kacie Athey, thank you somuch for being here today.
I we we I think that that was avery good dive and swim through

(55:46):
the world of parasites. So Ireally enjoyed that. Thank you
so much.

Thank you for having me.

Right. And, Ken, thank you for for editing and
being here. Once again, Iappreciate you. Thanks for that.
I I I love the the Mothmancostume.
I love the Darth Vader. So happyHalloween, 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'mnot 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 iscold. And so, yeah, we're we
will get back into thehorticulture 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 topicGuardian topic next week. Well,

(56:50):
listeners, thank you for doingwhat you do best, and that is
listening. Or if you watched uson YouTube, watch it. And as
always, keep on growing.

Flying around about the time that those caterpillars
are, yeah, about halfway theirthe 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. Soit's not the cat

Bears.

Parasitoid is like

Polish sausage. Polish sausage. Polish sausage.
Okay. I don't know if that'sChicago.
If not, just, like, NorthernMinnesota.

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.css-14f5ked{margin:0;word-break:break-word;display:-webkit-box;-webkit-box-orient:vertical;box-orient:vertical;-webkit-line-clamp:2;overflow:hidden;}Ep. 230 From alien wasps to zombie ants, parasites are all around | #GoodGrowing