Uncovering Cicada Killer Wasps: Unsung Heroes in the Garden

In this episode of the Sunshine Gardening podcast, Dr. Ric Bessin, an entomologist from the University of Kentucky, explains the beneficial nature of Cicada Killer Wasps. These wasps control cicada populations, are generally non-aggressive, and should not cause undue concern. He also highlights their positive environmental contributions and encourages minimizing pesticide use.

Episode Transcript

(00:00):
Welcome to the Sunshine Gardening podcast
where we delve into the fascinating world of
Kentucky gardening.
I'm your host, Kristen Hildebrand,
and today we're exploring a particularly
intriguing creature,
the cicada killer wasp.
Often misunderstood
and sometimes feared due to their large size

(00:20):
and stinger,
these impressive insects play a crucial role in
our ecosystem.
To discuss the cicada killer wasp in more
detail,
we invited doctor Rick Besson, our University of
Kentucky Extension entomologist
with a rich background in studying insects,
particularly within Kentucky's ecosystem, to chat with us

(00:41):
on the podcast.
Together, we will uncover the cicada killer wasp
life cycle,
habits, and benefits
and learn why they might just be the
unsung heroes of your Kentucky garden.
So grab your gardening gloves and trials, and
let's dig in.
Welcome to the Sunshine Gardening podcast.

(01:03):
This gardening show will equip and inspire avid
gardeners with tips and tricks to help them
navigate the gardening world. The show will also
highlight specific growing requirements for seasonal plants so
the sun will shine brighter over their Kentucky
garden.
And now, here's that ray of sunshine,
garden enthusiast and horticulture

(01:23):
extension agent, Kristen Hildebrand, with the University of
Kentucky Cooperative Extension Service.
Welcome back to the sunshine gardening podcast. And
joining with us today is doctor Rick Besson.
How are you doctor Besson?
I'm doing
great. I am so glad that you were
able to come on the podcast today because

(01:45):
we have been getting some office calls
and even visits here recently.
I know we're recording here, a little bit
after August, August 5th.
But it's about a particular insect that I
think is raising some concern for a lot
of homeowners when they're out and about in
their lawn and landscape,
and that is the cicada killer wasp.

(02:07):
And I was hoping that you could come
on and provide some of your expertise in
this area as our UK entomologist
and just kind of explain a little bit
more about the cicada
killer wasp and why is it kind of
mistaken for, a bad insect.
Okay. Well, you got a lot wrapped up
in those questions.
Let me go ahead and get started. So

(02:27):
the the cicada killer, when they come out,
that's a sure sign
you're in the, the midsummer.
I mean, this is truly a mid
summer
insect that emerges. We're getting lots of calls
about them. You know, people get concerned about
them. They're not sure what they are. They're
threatened by them and things like that. They
mistake them for other insects. We'll address that

(02:49):
too.
You know, cicada killers are called cicada killers
because they go out and they hunt cicadas.
And the particular
cicada
they hunt is called the dog day cicada.
And so that tells me we're in the
dog days of of summer. We're in the
heat of summer right now, and the cicada
killers are out. So they're out and patrolling

(03:11):
and doing their things.
Now a lot of people get concerned because
they hear about things in the media.
You know, they see the cicada. This is
a large
imposing
wasp. They can be anywhere from
3 quarters of an inch to, you know,
2 inches in length. You know, and a
2 inch flying insect

(03:32):
is huge. You know, it's it's the Godzilla
among,
wasps out there.
And so, you know, people get alarmed when
they see it, and
they think it may be some other things.
And so they they may think it's a
hornet. And we do have a few hornets
in Kentucky. We have
the bald faced hornet, which is black and

(03:52):
white, and that's easy to tell it's different.
But we also have
the European hornet, which is similar in coloration
to the cicada killer. And I think that
those 2 get confused
a lot with people that don't see these
very often. But, you know, there's some things
that make the cicada killer a little bit
different

(04:13):
than the European hornet. One is the cicada
killer has more reddish eyes.
The European hornet has black eyes.
I would describe
the European hornet as yellow
with some black markings.
Whereas the cicada killer would be more black
with some yellow markings. So they're sort of

(04:35):
mirror opposites. See, although they're both yellow and
black, they're they're a little bit different. And
then the cicada killer is a little bit
bigger,
and it it tends to be more pointed.
It has a a pointy tip on the
abdomen that that it's more of a a
blunter tip on the European hornet.
The other one that people sometimes get very

(04:56):
upset about in the last couple years they
have,
thinking that the cicada killers
were what people are calling this murder hornet.
We try and call it the Asian hornet,
but they were thinking it was the murder
hornet. And we do not have murder hornets
in Kentucky. We don't have them
within, you know, more than a 1000 miles
from this they just do not occur here.

(05:19):
They don't they're not getting here. They're not
on their way.
So these are cicada killers.
Yes. Well and I had a particular instance.
It was an older gentleman. He brought it
into the office, the actual insect, and he
said, I just wanted to make sure that
this was actually the murder hornet that I
was killing because he was concerned about it
taking away the bees. And like you said,

(05:41):
we had that in the media, and it
really did alarm folks. But it's good to
know that we have not seen it in
Kentucky, so rest assured
that's always good information.
But like you said, people are seeing it
more right now, and they're just, you know,
kinda concerned again that it might be another
hornet too. And you mentioned a little bit
about some of the differences.

(06:02):
Is there any other distinctive features that the
cicada killer wasp
can you know, people can have to correctly
identify it. I know I've seen some literature
that it talks about females may have more
of the stinger,
and I believe the males do not. Is
that correct?
Correct. And so one thing that's true with

(06:23):
all the bees and wasps and ants
is that only females
can sting
because it's actually a modified egg layer
is the stinger.
So males,
male bees, male wasps, male ants do not
have stingers, cannot sting. That's just there's no
exceptions to that. It's it's only females in

(06:45):
that group.
Now one other distinctive feature between the European
hornet
and the cicada killer is particularly with the
females.
A lot of times you can see that
tip of that stinger. And it's a very
impressive stinger
sticking out the tip of the abdomen. And
you just don't see that with the European

(07:05):
hornet. It's a retractable. Both of them are
retractable, but the European
hornet retracts it all the way into the
abdomen
most of the time. And so you don't
see it. And it's a it's a thinner,
more needle like stinger than than the, cicada
killer, which has a very prominent,
bear very strong
stinger, on the back.

(07:27):
There's also some differences in how likely you
are to get stung by these insects. You
know, one huge difference is
the European hornet
is very defensive
around their colonies. You know, you mess with
a hornet's nest, you are gonna lose that
battle. They're gonna come pouring out, and they're
gonna they're gonna sting you because they defend

(07:50):
their nest. And their nest is made up
of many individual, dozens and dozens of hornets
in that nest.
The cicada killer
does not defend its nest.
And so if you if you run over
a a ground nest, they nest in the
ground. Let's say it's in your lawn and
you run over with a lawnmower. They may
fly out, but they're not gonna attack you.

(08:11):
They don't defend their nest. It's not not
in their nature.
The other thing is
each nest only has a single wasp in
it. So you're not gonna get dozens that
pour out of a ground nest because no,
they're they're solitary.
It's just
one nest,
one female wasp.
Now there may be multiple nests in the

(08:32):
area, each with their own wasp, but they're
the each nest is just a solitary wasp
that makes it and they don't defend their
nest.
So
people are more prone to get stung,
much more prone to get stung by a
European hornet than they ever would from a
cicada killer wasp. So that that's really good
news. They're the cicada killers can be common.

(08:54):
They they can be alarming to people when
they see them,
but the risk
is extremely small. Now if you if you
if you pick one up and you hold
it in your hand or you you step
on 1 with bare feet, yeah, you can
get stung.
But it it it feels
very mild. It's a very mild sting, feels
more like a pinprick.

(09:15):
It's not that very painful sting you'd get
with, say, a a honeybee or a a
hornet or something like that that more of
a a burning, very, very painful sting.
Right. Right. And I'm glad that you talked
about a little bit some more about the
differences
because those hornets, I mean, they are very,
very aggressive.
And it's good to know that the cicada

(09:35):
killer is a little bit different in the
fact that it's not gonna defend its nest.
I was curious when you talked about nest,
I was hoping that you could elaborate
a little bit more about the cicada killer's
life cycle
and a little bit more about its habitat.
Because like you said, we're in the dog
days of summer, so we're seeing more of
them right now. But can you walk us
through what that looks like?

(09:57):
Okay. And let me just focus in on
the cicada killer wasp. And so there's males
and there's females.
The female makes her nest in the ground.
The she likes well drained soil, so she
doesn't like wet soil.
She likes it a little bit open. You
know, a really thick lawn
does not promote cicada killers. But, you know,

(10:17):
if you have thinner patches in your lawn
or or maybe you have patches where where
shrubs overhang the lawn and there's a shaded
area where it's a little thinner, Those are
potential habitats that, you know, a cicada killer
could pick to to make her nest.
Over her lifespan, she may makes several of
these nests. Now underground, she's gonna make the

(10:38):
nest during the summer.
And there may be several burrows in there.
Each e well, several,
I should say, chambers in a burrow.
And each of those, she's gonna provision
with cicadas.
So she goes out and she finds the
cicadas. When she finds one,
she stings it. She immobilizes it. She puts

(11:00):
it under her body. She holds on to
it with her legs,
and she carries it back to her burrow.
And that sounds
like a plan. But, you know, not all
plans work out.
That's right. That's right. But, you know, it's
like she is a hunter for these cicadas.
And sometimes,
she's such a good hunter. She catches something

(11:22):
she can't lift.
And so, you know, even though the plan
is she's gonna carry it back to her
burrow and sometimes, well, that doesn't work out.
And so she has a plan b.
And her plan b is to put that
underneath her legs and she carries it. And
she may climb a tree holding onto that
cicada. She'll get to the top of the
tree
and she'll sort of fly slash glide as

(11:45):
far as she can.
Then she'll find another tree and she'll go
up. She'll fly and glide until she gets
all the way back to her burrow.
Sometimes when there's at a tree with there's
no tree, you may see cicada killers actually
dragging the cicada over the ground,
getting back to her burrow. But she'll do
this. And then she'll lay an egg. Once

(12:06):
she buries it in the chamber, she lays
an egg on the cicada,
and that that egg hatches and that cicada
larva
will feed on that cicada,
and it it will use that cicada as
its food source. And the next year, you'll
get a cicada killer wasp that that came
from that, that larva.

(12:26):
Now with the males, male cicada killers are
a little bit smaller than the females.
That's because the female usually
only captures 1 male or 1 cicada
for a male. They don't need as much
energy as as the female. Whereas a female,
where she's gonna lay a a female egg,

(12:46):
she may provide 2 or 3 cicadas
for it to feed on, and you get
a much larger
female cicada.
So a little bit different.
Now one other thing that's a little bit
different is that the female goes out and
hunts for cicadas. The male does not.
Really, the male is patrolling for females.

(13:07):
I mean, that's what it does.
And, you know, particularly where people have some
of these burrows in their lawns or or
in their their gardens and they get concerned
about them, they'll see the females and they
usually fly very quickly away from their their
nest and they they come back very quickly.
They don't bother anything. But the males sorta
hover around

(13:29):
these nesting areas.
And if someone walks over there, the male,
it will threaten other male cicada killer wasps.
And it also may, you know, act like
a threat to people too. But keep in
mind, the male has no stinger.
It's just all bluster
with the male. And so they do act
a little bit more aggressive

(13:49):
and and they do react to people. The
female really doesn't. But
all in all, the cicada killers, I think
they they provide an important service. You know,
they're helping to control
cicada populations.
They're not aggressive.
Yes, it's possible to get stung, but it's
very rare. And even when someone does get
stung,
it's

(14:10):
generally not a health issue at all. It's
important to recognize what's out there
and what the relative risks are.
Yeah. And like for the cicadas,
a lot of times they can do some
damage for younger trees in the landscape.
So it's like you said, it's like mother
nature's way of helping us with the cicada

(14:31):
population.
Yes. Yeah. And,
I was in the woods this weekend,
and I I was sitting in the woods
trying to listen and hear birds in the
woods.
And, unfortunately, I couldn't hear them over the
cicada calls.
So I was actually hoping for more cicada
killer wasps to reduce the noise from the
cicadas. Yeah. And you brought up a really

(14:52):
good fact there. Do these cicada killer wasps,
do they have any kind of noise about
them when they're kinda patrolling or, like you
said, looking for cicadas at all? No. I've
I've never heard any any noise. And,
you know, the the males around the nest,
you hear a little bit of buzzing just
as they're flying around. But, you know, the
the the, cicada killer wasp, if they were

(15:13):
hunting for cicadas in your yard, they would
be up in the trees, and you would
probably never notice it. You know, they're they're
not gonna be in spots where where they
really interact with us. The only place you
really interact with a cicada killer not wasp
is where you have those burrows in the
ground.
And
some people do get a little bit upset

(15:34):
with the burrowing activity of the cicada killers
just because the the hole is about a
half inch in size and it can be
almost a foot down in the ground, so
they bring up a lot of dirt material.
And sometimes you see that coming up on
the lawns where you have a lot of
nests or you may see that spilling onto
sidewalks. And so it can be a little
bit unsightly with that.

(15:55):
But, you know, that's more of a nuisance
than you know, it's it's really not degrading
the lawn or or other things. It it's
more just a visual
nuisance. Now in in terms of homeowners that
don't want that, you know, there's some things
that they can do to reduce the attractiveness
for nests.
Cicadas really don't like wet ground, so

(16:17):
deep watering of those areas
makes it less favorable for for cicadas.
You know, if you have a a thicker
lawn, you know, higher mowing height, that type
of thing, That's good for your lawn. It's
also good at, you know, reducing the number
of cicada killer wasps.
You know, if they're a lot underneath some
bushes and and shrubs in the garden, you

(16:39):
know, a layer of mulch
there can,
can help reduce those things. So there's some
simple things we can do
rather than, you know, grabbing the pesticide off
off the shelf to, solve the problem.
Yeah. And that seems to be, like, instinct
of ours. You know, we wanna take care
of ourselves
and our environment around us. And does the

(17:00):
cicada killer wasp, does it kinda harm any
pets that might be outdoors?
Well, that depends
because
not all pests act the same. And so,
you know, if if you happen to have
a dog or cat that likes you know,
I've I've seen dogs that they chase bumblebees
and they try and eat bumblebees

(17:20):
and things like that.
You know, if they try and eat a
female cicada killer wasp, I don't know what's
gonna happen. All bets are off. But generally,
for pets that tend to leave things alone,
there's no problem at all. But, you know,
the not all of our pets are that
way. Some some are more,
adventurous.
Exactly. Exactly. So I guess it just like

(17:43):
you said, it depends on the case and
your pet too. But I was curious about
that, you know, because they are outside in
that area where the cicada killer wasp can
be. So I wanted to ask you that.
You know, as far as, like, knowing a
little bit more about these particular
wasp and things like that, is there any
other thing that we need to probably realize,

(18:05):
especially, like, I know they take care of
the cicadas that build up. But are they
doing any other,
like, particular
role in for our environment besides that? Yeah.
Yeah. Well, let let let's talk about someone's
lawn. It's like Mhmm. I talked about the
negative aspect
that, you know, their the tailings from their
tunneling
that being an issue in the lawn. But

(18:27):
at the same time,
they're creating aeration by tunneling into the lawn.
They're dropping
cicadas in there. And, you know, one of
those burrows
can have
many dozen
cicadas in there.
And, yeah, the the cicada killer wasp larvae
eat some of it. They don't eat all
of it, and you actually get some nutrients

(18:49):
deposited
in your lawn. So, you know, it it
helps to feed your lawn midsummer when you
may not have a lot of food for
your lawn out there. And so a lot
of times we tend to focus on the
negatives, but there's also positives.
And I think having a low number of
cicada killer wasps, you know, in and around
your home, it can be a very good

(19:10):
thing.
I have seen some situations where you just
have too many, you know, where where where
you may have
50 to a 100
boroughs and the wasp. And it's like, no.
You you probably need to do that. You
may may need to rethink,
you know, your landscaping.
So so it's not not a a hotel
for,
cicada killer wasps.

(19:31):
But, yeah, they they provide an important role.
Controlling cicadas, they tend to be specialists. They're
not after
stink bugs or grasshoppers
or anything like that. They are after
cicadas.
Now if we happen to have a year
where the
periodical
cicada comes out a little bit late,

(19:52):
some of those actually may be attacked by
the cicada killer wasp, the very early emergers.
Usually, they're they're separate, but they're not always
separate.
And so they can help out a little
bit with the periodical cicada.
And by the way, if if someone happened
to miss out on the cicadas,
the periodical cicada this year, well, next year

(20:14):
is gonna be your year because that that's
when we're gonna get the periodical cicada across
the state of Kentucky.
So So we may see a little bit
more cicada killer wasp out and about just
because of that. Correct?
Yes. Yeah. And another
question I get occasionally
is, well, I'm seeing a lot of cicada
killer wasps out this year. Is that because

(20:35):
there's a lot of cicadas out this year?
Mhmm. And the question really is,
cicadas out this year?
Mhmm. And the question really is or the
answer really is, it depends upon
what the cicadas were last year because the
wasps you see this year
were produced last year from last year's cicadas.
And so if we have a boom year
for cicada killer wasps this year, probably meant

(20:56):
we had a boom year for cicadas last
year. So this year is gonna affect what
we see next year. Yes. Yes. And the
ones that I have seen so far from
pictures and then that one gentleman that brought
in that sample, it was fairly large. So
I knew he had been around for or
she had been around. One was a female.
I think the other one was a male.
But I really appreciate you talking about this

(21:18):
particular
wasp because it is so important to kinda
know the differences,
and I know that you've helped a lot
of people out just by talking about some
of the identifiers with this particular insect too.
Is there any way that the public can
help conserve
these wasp? I know you kinda mentioned if
they have a big population, but maybe there's
some things that we can do to help

(21:40):
them as well.
Yeah. I mean, there are some things that
that that people can do. And and really,
one of the things that that I I
really recommend is limiting some of the insecticides
they may use,
you know, in their lawn and landscape. Now
I'm not
completely anti pesticide,
but I do feel strongly we should only

(22:01):
use them when they're actually needed.
And there's a lot of times, you know,
people say, well, you know,
it's the 5th August. I I need to
go out and use an insecticide on my
lawn. That's not a good reason to use
an insecticide.
You know, it's because I have a particular
problem
or or there's
indications that this problem is about to hit
and that now is the time to treat

(22:22):
it. And so I I would
in terms of preserving
the cicada killer wasp,
limiting the insecticide
applications
that people make. Another
thing I didn't bring up with the cicada
killer
is that some people that are concerned, they're
seeing their wasps like, how long is it
gonna be,
you know, in, in my garden? How long

(22:43):
am I gonna have to put up with
this?
And that they're not active that long. You
know, it's gonna be 6,
maybe 8 weeks
maximum that you see this activity. So they're
gonna come out at the end of July.
It's really sometime in in September
that their activity diminishes. We only see 1

(23:04):
generation per year, so there's only one emergence
of the cicada killers. And they're not gonna
come out again till
next July in 2025.
And it seems like it's been an earlier
or I should say, it's been warmer this
year. I think it's gotten warmer
gradually. You know? But I know that we've
probably seen a little bit earlier activity this

(23:26):
year versus some other years. So I appreciate
you kinda talking to us about that too.
Now I know that there's a lot of
things that we've covered particularly in this podcast
episode about this, Kayda killer wasp.
Is there any other information that you could
recommend in written form if people wanted to
go back and check this out? Yes. Thank
you for,
asking me that because we have a fact

(23:48):
sheet. It's available
online
at the UK Entomology
website.
So if you search on UK
Entomology,
cicada killer wasp, it will bring up the
fact sheet. They're they're free of charge. It's
it's the latest information.
And I have to say we tailor that
towards Kentucky.

(24:08):
So it's really meant for, you know, Kentucky
residents. And,
you know, if you're listening to this podcast
from another state, your state may also have
some fact sheets or other materials available.
The one thing I'm very biased in what
I recommend online, but
when you look for information, I always recommend
that, you look to see if it's from

(24:29):
a site
Internet site that ends in dot edu.
And that means it's from an educational
organization.
They don't have any vested interests. They're not
trying to sell you something.
But, you know, if you're in Kentucky, I
recommend that you come to our website and
check out our our fact sheet for more
information.
If you're in another state, see what your
state has available.

(24:50):
Yeah. Yeah. And if anybody does have questions
about identifying
the cicada killer wasp, you can always send
it in to us at the extension office.
I certainly appreciate you mentioning the entomology fact
sheet. You all do a great job of
passing that information to us from the university
so that way we can pass it on
to the clients. So thanks for all that
you do, doctor Besson. Thank you for coming

(25:12):
on the show today with us too, and
we'll definitely have to have you back again
next time.
Okay. Well, thank you, Kristen.
Thank you for listening to the Sunshine Gardening
podcast.
We thank doctor Rick Besson for sharing his
valuable insights as our guest in this episode.
We hope you found the discussion about the
cicada killer wasp and its vital role in

(25:33):
maintaining garden ecosystems
informative.
It's essential to recognize that not all insects
are pests.
Some, like the cicada killer wasp, are beneficial
allies in our gardening efforts
and we should value their contributions.
To access the publication mentioned by Doctor. Rick
Besson in today's episode,

(25:54):
please refer to the show notes for episode
36
over on the blog at warrencountyagriculture.com.
Now if you enjoyed today's episode,
we would be incredibly grateful if you could
leave a review on your preferred podcast platform.
Your reviews help us connect with more people
and provide valuable feedback for improvement.

(26:17):
Also, feel free to reach out with any
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Remember to subscribe to the Sunshine Gardening podcast
for more gardening insights,
and join us next time as we explore
new ways to cultivate the garden of your
dreams. Until then,
happy gardening.

(26:38):
Thanks for listening to the Sunshine Gardening podcast
with Kristen Hildebrand.
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Gardeners keep on digging and learning more about
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(27:00):
Hildebrand is a production of the University of
Kentucky Cooperative Extension Service.