- The next speaker is Christelle Guedot.
She is the fruit crop entomologist
and extension specialist at UW Madison,
and she's going to talk about pest management in apple.
- Good morning, everybody.
This is going to be a little tricky because I got to look
at my slides back, so we'll try to make it work.
So I was asked,
I kind of asked the apple board what they wanted me
to talk about because I wasn't sure
what you guys were interested in.
I had a couple requests, and I focused on apple maggots.
So I'm going to tell you about
the basic biology of apple maggot and then
about a study from 2012 that can be applicable to you,
and then I'll talk to you about brown marmorated stink bug
after that.
So, okay.
So apple maggot, I hope you guys all know
what they look like.
They're in the family Tephritidae,
so they would be our fruit flies, right?
A lot of people call fruit flies those Drosophila.
Those are vinegar flies.
And apple maggot is part of the real fruit flies.
So they're flies.
On the left-hand side, you have the female
and some of the characteristics.
It has four white bands.
And the male is shorter with a more rounded abdomen
and only three bands on the abdomen.
I'm not going over everything
because I'm assuming you guys know a lot about it,
but they are a pest that you'll see in end of June,
early July.
And they will emerge from the soil
and it's at about 900 growing degrees day with a base 50,
but there's two different models you can use.
And the problem with apple maggot
is that they are very much linked to temperature
and humidity, so the models are not as clear cut
as you would for like, say, codling moth.
So they're a little bit different,
they don't work as well compared to those kind of moths.
Peak emergence is between 1400 and 1700 growing degree day.
You actually only have one generation.
Once they start, it's continuous emergence
throughout the summer, and it's very much linked
to temperature and humidity
and soil moisture.
And what's very interesting with apple maggot
is that during the pre-oviposition period,
so before they start laying eggs,
when they first come out of the soil,
the adults are only interested in feeding on pollen,
honeydew, bird feces.
They're looking for protein to develop their ovaries
to be able to mate and lay eggs.
So that period is very critical,
and we'll talk about that for monitoring and management.
And then eight to 10 days later,
the females are then ready to mate,
and they're ready to lay their eggs.
So that's the oviposition period,
and that has implications too.
So if you'll look at the oviposition scars,
they're very, very small.
They're hard to see.
The female will just puncture the skin,
lay its eggs underneath the skin of the fruit.
They lay one egg at a time.
And they can start laying eggs again
after that pre-oviposition period.
So eight to 10 days after emergence.
They can lay up to 300 or 500 eggs per female.
And if you look at this slide,
this slide has a lot of oviposition scars.
And so if you look here, you have this sunken area,
but it's kind of hard to tell,
especially when you have those lenticels
to see where the oviposition scar is,
where the egg was laid.
And so if you look up closely,
this is actually where the oviposition scar is.
So what happens is as the female lay its eggs
underneath the skin of the fruit,
the flesh of the fruit near that where the larva
will start feeding doesn't develop
with the rest of the fruit.
So you have the scarring that will occur.
And so if you cut,
if you do a lateral cut of the fruit,
this is what you'll see.
You have those very brown, faint brown trails in there.
The larvae are very small and tiny.
They're hard to find.
That's why they are called the railroad worm,
in part of it, because of those trails that they make.
But then, as the larva continues feeding on the fruit,
that's when you definitely can see the damage.
It's much easier to see as the larva gets bigger
and it gets substantially rotted.
And what happens is that the fruit will then
drop to the ground, which is perfect because the larvae
tend to go out of the fruit and go pupate
under the leaf litter.
So it's perfect for them.
And they'll pupate in two up to three inches of the soil.
So when it comes to monitoring the flies,
you want to be doing,
so you can do visual inspection.
Those flies are pretty conspicuous,
and I didn't put up the slide where you have
the wing patterns, but it's kind of that W
or kind of F pattern that you can see on the wings.
They have the black pattern.
And so you can look for the flies,
but then you can hang traps, right?
So towards the last week of June,
you have two types of traps that you can hang.
So if we go back to that biology,
that oviposition period,
it's very important to think about that.
If you do a yellow, those yellow sticky cards,
and I'll show you pictures of that after,
and you can bait them with a feeding attractant,
it's an ammonium lure.
These, the yellow sticky card,
the idea is that
for insects, they look the same in foliage.
They have the same color that the insects see foliage.
So they will attract those
pre-oviposition females.
And the feeding attractant lure attracts them
when they're looking for that food, that protein,
to develop the ovaries before they are mating.
Then, after that, when we're done
with that pre-oviposition period,
what they're looking for is a place to oviposit,
to lay their eggs in.
So then they're looking for the fruit,
and that's when we start using those red spheres.
Some can be baited. Some are used also unbaited.
And then, at that point,
we're looking at different attractants.
Here it will be ripe fruit lures
that target those females that are mated
and are looking for an oviposition site.
So these are the yellow sticky cards.
Obviously, they attract a lot of insects.
So you have to be very careful in how you identify
your insect, and that's the key to any kind
of integrated pest management,
is obviously knowing what insects you're looking at.
And then these are the red baited sticky sphere.
Here, this one is not baited,
but the idea is that you have this tangle foot,
this sticky material, and if you can have the lure
that you can see up here,
but even without the lure, these still work
because the females are looking for those fruit,
and then the killing agent is that sticky material, right?
So they get stuck on there, and that's how they die.
So, of course, as you can see on the right-hand side,
you're going to have a lot of insects that are glued there
and it's kind of messy business
to deal with those spheres.
So there's different options you can do.
Trap-out has been one that's been suggested
for apple maggot.
So it's best when you have low densities of flies.
And you can use those sticky spheres with the lure.
About one trap per hundred apples.
So that gets very
extensive kind of trapping that you need to do.
But perimeter trap-out seems to work, right?
There's been studies that have shown that, that's working,
if you do it in the perimeter, as a lot of them
are coming from outside your orchard.
And then you want to have interior traps
that will check that your perimeter traps
are actually working and preventing your flies
from establishing in your orchard.
But it's, as I mentioned, labor intensive
when you're talking about one trap per hundred apples.
And you need to clean the trap at least biweekly.
So that's very labor intensive.
So the study I wanted to talk to you about
comes from 2012,
but I haven't talked to you about it,
so I think it's a very interesting study.
And the title of that study is
integration of insecticidal, phagostimulatory,
so that's means it stimulates feeding,
and visual elements of an attract and kill system
for apple maggot fly.
So it stems from,
and you have the information down there
if you want to find that paper.
But it stems from the idea of the red spheres, right?
So that's from the people, the same lab and the people
that started this whole Prokopy,
the person that was starting that for apple maggot.
So the idea is that these spheres are time consuming.
Everything I just mentioned in the previous slide.
And so there had been development from that same lab
in West Virginia, where they looked at,
So this is a black and white picture from that paper,
but this is a red sphere too.
And on top here, you have a cylinder,
and that cylinder, what they did is,
So that's not this paper, right?
I'm just giving you the background here.
They put in that cylinder some sucrose.
So they would attract the flies when they come,
not attract, the flies will come to the red sphere
and get stimulated, that phagostimulatory.
They would get stimulated to feed.
And you can put then an insecticide
on the red sphere and kill them.
That will be your trap-out. As they come in, you kill them.
And so you don't have any more sticky material there.
You're just killing them as they touch the sphere.
So that was,
step one was the red sphere.
Step two was that sphere with that sucrose solution
on top.
But there's limitation with that,
and one of the big limitations to that
is that the cylinder on top is sugar.
The insecticide is on the sphere,
and what they found is a lot of flies would go
onto the sugar part of the trap
and not actually go to the sphere.
So they went the next step further,
and that's what this study is about.
So they were.
They compared this red sphere topped
with the cylindrical cap and then this one.
So it's hard to tell, but there is a cap here
that's embedded onto the sphere, right?
So part of it is visual cues,
looking if the red sphere is best for attracting the flies.
And it actually wasn't a problem with the cylinder,
but they wanted to do that.
And what they did is in this case,
they did two things to improve from the previous design.
The sugar is included in that top cap.
Can you see this part here?
Here?
This half, or not half but
moon-shaped thing.
This has the sugar, and the concentration that you,
20% wax, 80% sucrose
and then they added Entrust.
That would be
organically approved and works really well.
And they put all that on there, right?
So we have both the sucrose
and the toxicant that's on the sphere.
And so the idea with this is that the sugar is on there
but it has to be released, right?
And because of the midwest, northeast,
there's a lot of rain.
So the rain is the one that's going to release the sugar
onto the sphere and get the flies to be stimulated
to feed on those spheres that have then the toxicant,
your insecticide.
Make sense?
So they did some lab assays and then field trials.
So I'm going to start with the lab assays.
And so here, this is,
They looked at it from the standpoint of the sphere
with the cylinder,
and they did different concentration of that spinosad,
so Entrust.
And so on the Y axis,
you have the percent mortality of the flies;
and on the X axis, it's the amount of rainfall
to see how much they can take of rain
before it's just not working anymore,
and how is the efficacy acting with the rainfall,
which is very important for us in areas
where we have a lot of rain.
So what they found here is that there was a significant
effect on the
concentration of the insecticide.
So you have here the control is the line
that would be at the very bottom,
and everything up is the step up in concentration.
So they did it in a power of 10.
And so, obviously, here what you can see on the data
is that the higher concentration got the highest
percent mortality,
and it decreases significantly with the decrease,
mortality decreases with the decrease in concentration.
And it dropped down from rainfall events.
Right?
So they simulated that
in a caged study.
So we have an effect of the concentration
and also in the amount of rainfall.
So the percent here, the maximum is 1%,
and we're at above 85% mortality
throughout all the different rainfall events
that is simulated here.
Here we're looking at this
other type of sphere, right?
The one that they're really addressing here
is to see if that's working.
I forgot to mention,
how do I go back?
Oh, yeah, yeah,
I forgot to mention on the rainfall here,
they went up to 25 centimeters of rainfall.
And that's obviously
a lot of rainfall, so that was over several days
that they did that.
It was a maximum of 2.5 centimeter
per 24 hours that they were applying.
So you can see 25 centimeters.
They stopped there because that's the average rainfall
they get in West Virginia.
Here, it's the same thing. It's a percent mortality.
The concentrations are a little different.
The top one is the 1%.
So it's saying the maximum that they had
in the previous study.
And then they did 50% and then tenth
and then hundredth and the control.
And on the rainfall, they went further.
They went all the way to 45 centimeters of rainfall.
So your 25 would be somewhere around here
to compare with the previous one.
And what they found here is that
at the 1% concentration,
they held to 100% mortality with this design,
all the way to 30 centimeters of rainfall.
So it holds really well, okay?
And then when they did the half percent, they still had,
it's not significant from the 1%.
So with half of the concentration
of what they had in the previous test,
they still get about 100% mortality.
So very, very promising.
For the lower concentration, if you look at them,
after the 7.5 centimeters and they don't talk so much,
I don't think it's significant of why it drops like that,
but then you can see that it increases.
Even with the tenth percent,
we're almost over 90% mortality.
So this system is working really well.
So this was, again, done in the lab.
And so what they did is they went into the field.
So they did field assessments.
The plots were two hectares
and they had four different farms
and they did a perimeter deployment.
Eight meters apart for 28 traps total per hectare, okay?
So perimeter trapping.
And in the middle of that, they put the unbaited
regular sticky sphere
just to have a way of checking what the population,
just as I mentioned before, for trap-out,
you would put those spheres in the interior
to see that your perimeter trapping is actually working.
So what they found here, there's the different
sampling dates on the left-hand side here,
and here are the four different farms.
What I surrounded in red are the treatments
where they put those spheres.
So again, it's the better sphere that they're testing,
right?
I shouldn't say better.
The one they were hoping were better,
but seems to be so far.
So that little cap, not the cylinder.
And they put those traps.
And then in the other plot at the same orchard,
they did insecticide spray.
So they compared the two.
And what they found is,
what you're looking at here is the mean number
of apple maggot that are caught on those interior traps
that are not treated, that are just red sticky sphere
to just check the population levels.
And at none of the times did they...
So they reached the two flies per sphere
is the threshold for spraying there.
And they went to that, but they never sprayed.
The growers never sprayed in the treatment
where they had the spheres.
They let it go.
And they reached the same number of times
above that threshold
with an insecticidal spray on the entire plot
than they did with that perimeter treatment
on the outside with no insecticidal spray.
And overall, what they found is that
there was no significant difference.
It was never, at any of the farms that they did that,
they had a significant difference
between the insecticidal spray and the,
and right now, unfortunately,
I can't remember what insecticide they used.
But what they had was the spheres.
So no insecticide at all and exactly the same amount
of control that they were getting at those four farms.
Then they looked, obviously they collected some fruit
to look at damage and infested fruit.
And they collected 10 fruit per tree
from 40 different trees in each plot.
And they just looked at the percent injury.
And here, same thing.
For the four different farms,
no significant difference between the sphere
as a treatment versus the conventional insecticide plot.
In all cases, they never reached more
than 1.25% injury.
Okay?
So overall,
what they found here, and this is the conclusion
for this study, that contoured cap,
these provide longer longevity, as I showed you
in those lab assays.
And even with half of the material,
it's still as efficient as what you would get
with the full amount of material with that cylinder
that they were comparing it to.
The rate of mortality for those lower concentrations
increased with the amount of rainfall.
For the higher concentration, it was at 100%.
So it can't go any further.
But for the lower concentration, it increases with rainfall.
And with the cylinder, it was actually decreasing,
if you recall, the graph,
with the amount of rainfall.
So there is a wire guard,
I didn't talk about that,
but how they put that sucrose and wax?
They compress it.
It's kind of an interesting process.
They put a food dye in there.
And then they put a guard, a wire guard,
that's embedded on the exterior of the surface,
and that protects the sphere, the sugar,
from invertebrates that could be,
or vertebrates I mean, that could be going there
and feeding on that because they've had issue with that
so they took care of that at the same time.
So I talked to the people last week
that have developed this,
and I was asking them, so where is this at?
This was published in 2012, where are we at
with this technology now because it seems
pretty promising?
It's obviously something that can easily be manufactured,
if a company picked it up.
The spheres are already sold, so why isn't it out
and available for growers?
And so Tracy Leskey was working at West Virginia
with the USDA and was telling me that
there was problems with the insecticide,
with that formulation of Entrust,
and the company wasn't really following through.
And I think it's a wettable powder.
It doesn't say in the paper exactly what it is.
But they weren't really following through,
so they thought that was going to fall out.
And then the same lab is working with those same spheres
for spotted wing drosophila.
And that's a huge market.
So she said that the company is again really interested
in this technology, and that could go further
for treatment for apple maggot, or management, I mean,
for apple maggot, because of the interest
for spotted sing drosophila.
So there is great hope in this technology
being available and maybe getting to the
commercial use for you guys to purchase
and test in your orchards.
So I think that's,
I hope that's going to be something in the near future
that we'll see available commercially.
Okay, so moving onto other methods.
You all know about Kaolin clay
that is available for apple maggot treatment.
The idea is you cover your fruit with this
diatomaceous earth.
It's just natural powder that you find.
It's that degradation of shells and stuff.
Like it's old earth, right, kind of thing.
So you cover your fruit.
It has its issues because, obviously,
as the fruit grows then you have to reapply.
As it rains, you might have to reapply.
But the idea is that it will deter the fly from laying eggs on there.
It doesn't kill the fly, it just deters them
from laying eggs on there.
So it works. It's just time consuming.
And then for chemical control,
there's action thresholds that are different.
If you use the yellow sticky card
or the unbaited red sphere,
then you would go with about two fly per week
before you start applying an insecticide.
And for the baited red sphere,
because they're more sensitive,
you can go up to five flies per week
before you apply an insecticide.
And here are just a list of insecticides.
I hope you all got your spray book
so that you can go back and refer to that
for your sprays.
But here I give you some of the efficacy
of those different insecticides that you can use
and pre-harvest interval and kind of the residual activity
that you would get with those different compounds.
So again, check the label
and do all your homework before using
any of those insecticides.
So I want to move on now, and I don't know how
I'm doing on time.
Okay, thank you.
But I want to talk to you,
last year I gave you a talk about brown marmorated
stink bugs, so I'm not going to bore you
with the same thing that I did last year,
but what I want to talk to you about is
you guys have funded us in the past
to do some insecticide trials that we're doing
at Peninsular Research Station,
and we were testing some of those soft chemistries
up there.
And so this year, what we are very interested
in asking you guys to fund is looking
at brown marmorated stink bug.
So just a quick overview of what it is,
and I don't know,
I brought one that I caught in my house,
but I don't have it.
So I'll have to see if I can get it.
I don't see the person that was supposed to bring it.
But the characteristics for that are here,
it's a smooth shoulder.
Some of the stink bugs have jetted edges
on their shoulders.
The main part is the white bands on the antennae.
The alternating colors on the outside of the abdomen here
between brown and white.
Then they are a stink bug besides that.
So if you squish them, which I did, they smell.
So nothing too surprising here.
But the adults would emerge in the spring,
in late March through June or so, depending on location.
And they will be based, again,
on degree day accumulation.
And we probably only have one generation in Wisconsin.
So this is the map that they put together.
And interestingly enough, that's done by Tracy Leskey,
the same person that has a lot of work
on brown marmorated stink bug.
And this is on a website called stopBMSB.org.
So you can go there and check it out.
And they update the map regularly.
So in this map of the US,
what you have in green is where it's been detected.
So if you see Wisconsin, we're green.
It's been detected in Wisconsin.
We know we have populations in Wisconsin.
In yellow, it's a nuisance problem only.
So they're coming into people's houses, but that's it,
which is not a good thing but it's not going
into agricultural crops.
In the orange, it's agricultural and nuisance problems.
And then in red, it's severe agricultural
and nuisance problems.
It was first introduced in Pennsylvania,
and as you can see, it's spreading.
We first detected them in 2010 in Wisconsin.
Michigan also detected them in 2010.
And you can see this year,
they just moved to the orange setting.
So they're not a nuisance problem.
They're now a nuisance and agricultural problem.
So what happens in every state where there's a problem
with brown marmorated stink bug, you go a couple years
with it's detected, it's there, we know.
We see them around houses,
then the numbers start building up.
And then, once they pass a certain,
We don't have a threshold for that,
but a certain number at some point,
that's when they start going into agricultural crops.
We're five years from the first detection.
We're getting to that point of the numbers going up.
At my house, I caught about 10 on my window in October.
And I was talking to different people in the state
that look at that.
PJ Liesch, our insect diagnostician
that gets all those phone calls and samples,
noticed also an increase in those records.
So for Wisconsin, this is what is confirmed now,
but these are only confirmed based on
people sending us a sample, a picture,
nothing that we are actually looking for.
Actually, DATCP has an active monitoring program,
and they haven't caught anything yet.
But here, what we're interested in doing,
so you see very few counties, but it doesn't mean
that that's all we have.
We just don't have reports from other places.
So this year,
Krista Hamilton from DATCP, Peter Werts from IPM Institute
and I had multiple conversations,
and what we think is that we've reached that level,
as I mentioned from Michigan,
where the numbers are building up.
We're still in urban areas where they're building up.
We have zero report of,
although there might be one today
but we'll have to confirm that.
So far we have zero report in any agricultural crop.
Okay?
Now is the time to really start monitoring
in those agricultural crops and see what's going on.
If there's going to be a year where they could start,
it's going to be this coming year.
So we all think, IPM Institute, DATCP and myself,
think that we need to work together to really go
and check in apple orchards.
And if people are interested that are in vegetable crops
or field crops, we'll be more than happy
to coordinate that too.
But what we want to do is really target
apple right now and see, are we seeing those
BMSB showing up there?
Even if it's in very low numbers
so we can really alert you guys and let you know,
okay, now is the time to really pay attention.
They're coming.
There's a lot of
what a lot of people would think are lookalikes.
So if you're not a collaborator,
for collaborators, we'll provide all the support you need.
But if you're not a collaborator and you don't know
but you want to know, please send us a picture
or send us the sample.
We'll be more than happy to tell you
because we want to know for your sake
but for everybody's sake.
So if you get anything and you're suspecting it could be,
don't hesitate to send me an email
or any of those people I mentioned or PJ Liesch,
the insect diagnostician,
we all talk amongst each other.
So we'll be able to keep track of that
and help you make sure the one in the lower middle here
is BMSB, and it's not necessarily easy
for an untrained eye or somebody panicking,
so we'll be happy to give you some information
of what it is.
And so PJ Liesch, the insect diagnostician, can help you.
And Rutgers University has a big program there,
so you can report to them if you want to.
But report to us, that would be great.
Thank you very much, everybody.
If you have any questions--
Thank you. (applause)