Ping Yu: (on-hold music) Hello, everyone.
Welcome to the Blooms and Beyond podcast, a podcast that uncovers plant history, culture, and management through the lens of science.
I'm your host, Ping.
How's everyone doing today?
As a plant person, I admit that I enjoy plants more than just about anything in the whole world.
But let's be honest, the life of ornamental plant isn't just all sunshine and chlorophyll.
Just like us human, um, they've got plenty of obstacles to, to face before they can shi- show off their beauty.
And one of the biggest challenging, uh, or troublemaker are pests.
Yes, the, um, invited party crackers of the plant world.
So today's, uh, star pest really know how to make their entrance, the red-headed flea beetles.
Now, don't let the name fool you.
It isn't funky rock band, uh, like The Beatles or a quirky superhero.
They are tiny, hoppy, and a leaf-chewing menace that puts plants through the ultimate makeover challenge.
The results of those, um, except the results aren't really pretty.
And a lot of growers know them well, maybe a little bit too well.
So in today's episode, we got Dr. Shimat Joseph, an entomologist, to chat about the, uh, flea beetles, what they like and how to s- spot them out,
what makes their beauty choice, and more importantly, some of the ways to manage them.
So grab your magnifying glasses, maybe a cup of coffee, and get ready because we're going to hop into the world of red-headed flea beetles.
I don't wanna steal any more thunder from our speaker today, so let's jump r-right into it.
Without further ado, here is my conversation with Dr. Shimat Joseph.
I hope you enjoy.
(on-hold music) So hello, Dr. Shimat Joseph.
Welcome to the podcast.
First, uh, first of all, let's start off, uh, with the introduction.
Can you tell us, the audience, a little bit about what you-- who you are and what you do?
Shimat Joseph: Sure.
So my name is Shimat Joseph, and, uh, I am an associate professor, uh, with Department of Entomology, University of Georgia.
Ping Yu: Mm-hmm.
Shimat Joseph: Uh, so I work with, uh, insect problems, uh, in turf and ornamentals.
Uh, since I have ornamentals, I work in nurseries and the landscape system where the pests are, uh, know, big problem, you know.
So in, uh, nurseries, I work with a variety of insects pests, but the main one that I focus at this moment is, uh, red-headed flea beetles.
This beetle was brought to my attention when I started the job here, and, uh, what I realized is that very less work been done with on this
pest.
Ping Yu: Mm-hmm.
Shimat Joseph: Um, the work, and I mean that, uh, the research that the growers need to manage this pest.
Ping Yu: Yeah.
So, uh, can you tell us about what first sparked your interest in horticulture or in the pest, and how do you come up-- how did this come into your
radar in the first place?
Shimat Joseph: Well, um, I did my bachelor's in agriculture.
Ping Yu: Mm-hmm.
Shimat Joseph: So I had opportunity to, um, see all different disciplines in agriculture.
That includes entomology.
Ping Yu: Oh, yeah.
Shimat Joseph: So I kind of, uh, over the years, like it's a four-year degree program, and, uh, towards like third or fourth year, I started developing interest in horticulture, also
entomology.
The two areas that I liked, and entomology for sure I liked it, uh, the most.
Ping Yu: (chuckles) So how-- what about, like you, how long have you been here at the UGA as a, um, entomologist for ornamentals?
Shimat Joseph: So I started, uh, in 2017.
Ping Yu: Mm-hmm.
Shimat Joseph: So it's, uh, about eight years now.
Ping Yu: Okay.
Shimat Joseph: So I am, uh, with UGA.
Ping Yu: Okay.
Shimat Joseph: Yeah.
Ping Yu: Uh, now let's move more into the pest and how-- can you tell us a little bit about the pest and what does it look like and how do they
behave out there in the, in the ornamental world?
Shimat Joseph: Right.
I would just start with its name.
Ping Yu: Mm-hmm.
Shimat Joseph: It's called red-headed flea beetle.
Ping Yu: Yeah.
Shimat Joseph: So there's two component, three components, I would say.
(chuckles) One is they're red.
Ping Yu: Mm-hmm.
Shimat Joseph: So they have a red tinge in their head (Ping Yu: Mm-hmm) the for-- in the forehead area.
Ping Yu: Yeah.
Shimat Joseph: And that's why we call it red.
It's a red tint, so that's where the red, redness come into play (Ping Yu: Mm-hmm) in the name.
It's a flea beetle.
Ping Yu: Yeah.
Shimat Joseph: So flea beetles, flea beetles usually have a elongated or a kind of stronger leg, I would say hind leg or rear leg, and that leg is basically
allowing them to jump.
Ping Yu: Okay.
Shimat Joseph: And that's why the flea, the jumping behavior (Ping Yu: Mm-hmm) that's why they call it flea beetles.
Ping Yu: Mm-hmm.
Shimat Joseph: And they're a beetle.
Ping Yu: Oh, yeah.
Shimat Joseph: So beetles, basically they're chewing mouthpart.
They feed and they munch on the plant, uh, uh, leaf tissue.
So this is, uh, uh, came to me, my attention when I started the job, when I visited the nurseries, where growers just showed me this damage, and they already
know.
Ping Yu: Mm-hmm.
Shimat Joseph: So when they ask- I asked them and they basically listed this is number one problem for them that they are dealing with for years and they need solution to
it, you know?
So this pest is, uh, like a beetle (Ping Yu: Mm-hmm) and it feeds on the plants.
And, uh, it's basically, in this p- particular beetle, they feeds on the, the surface of the leaf, and they basically rasp these leaves.
They basically gnaw it.
And, uh, in that process they remove the cell, uh, the cells and tissue on the leaf.
Ping Yu: Okay.
Shimat Joseph: And with time what happens is that, that the area that they fed becomes sunken and, uh, disintegrates and becomes holes.
Ping Yu: Mm-hmm.
Shimat Joseph: And if they feed multiple times, it becomes like a shot hole.
So you'll see the leaf kind of lot of shot holes on the leaves.
And that is basically appears like a, uh, skeletonization.
Because you see the leaves has a, uh, veins and other areas, right?
They start feeding on the e- the areas between the veins, and if there are a lot of feeding going on, the leaf look like skeletonized.
Ping Yu: Okay.
Shimat Joseph: Only their veins remain.
Ping Yu: Okay.
Shimat Joseph: And with time, that leaf will fall.
So in nursery world, this is not acceptable, right?
Ping Yu: Y- yeah.
Shimat Joseph: Because they had to sell the crop.
Ping Yu: Especially in ornamental.
Shimat Joseph: Correct.
Ping Yu: Yeah.
Shimat Joseph: Yeah, everything needs to be clean as much as possible if we're to sell it.
So that is the challenge here.
Ping Yu: Mm-hmm.
Shimat Joseph: So these beetles feeds on that as adult.
They...
When they mate, uh (Ping Yu: Mm-hmm) and they start going into the soil.
Ping Yu: Okay.
Shimat Joseph: In this case, it is a container with a growing medium in there.
Ping Yu: Yeah.
Shimat Joseph: So we have pine bark as a main.
That's what predominantly growers here use.
Well- they start laying eggs, and the eggs hatch, uh, with whatever time, depending on temperature.
Ping Yu: Mm-hmm.
Shimat Joseph: And the larvae just start feeding on the roots.
Ping Yu: Okay.
Shimat Joseph: So they start re- feeding on the roots, and they go through about three weeks like that, and they molt into a stage called pupa.
Ping Yu: Mm-hmm.
Shimat Joseph: That's basically a resting phase.
Again, that's happening in the, in the pot itself.
Ping Yu: In the soil.
Shimat Joseph: so- the growing media of (Ping Yu: Yeah) container.
And after, like, couple of weeks, they emerge out as adults, mate, and the cycle continues.
Ping Yu: Okay.
So, um, for anyone who's listening who does not know anything about entomology or, um, as a layperson, how do you tell them, like,
what does this pest look like?
How do you tell them apart and this is the insect, this is not.
So can you tell our audience and how you tell this pest apart from other normal pests, like ants or roach?
Like, people would know 'cause we already covered the red he- the red head part, but what about the main, uh, common
characteristic that a layman or not a pest people would know?
Shimat Joseph: That's a good question.
So yes, this is- they are beetles.
So beetles have a hard exoskeleton, meaning hard covering.
Ping Yu: Okay.
Shimat Joseph: So insects are unlike us.
They have a outer shell.
Ping Yu: Okay.
Shimat Joseph: And they are segmented.
Ping Yu: Yeah.
Shimat Joseph: Right?
Ping Yu: Yeah.
Shimat Joseph: So insects, you're right, they have three pairs of legs.
Ping Yu: Oh, yeah.
Shimat Joseph: And, uh, in this case, they have a pair of antenna (Ping Yu: Mm-hmm) and, uh, two pairs of wings, right?
Ping Yu: Okay.
Yeah.
Shimat Joseph: And the first pair of wings is basically hardened, and they basically, they use that for protection of the body.
Ping Yu: Okay.
Shimat Joseph: And that's basically in the back, usually.
Ping Yu: Yeah.
Shimat Joseph: And they have the, the second pair that is more filamentous.
And when they're in flight, they open up the upper, the, the front or fore wing (Ping Yu: Mm-hmm) up and the hind wing, the, the wing that is beneath that (Ping Yu: Mm-hmm)
it expands and they fly.
That's how the beetles are.
Ping Yu: Okay.
Shimat Joseph: And all the beetles, unlike other hemipterans or other bugs that you're talking about, like, they have a straw-like mouthparts and, you know, some has a, a rasping-type mouthpart.
Ping Yu: Mm-hmm.
Shimat Joseph: And you might have seen lapping mouthpart with honeybees and (Ping Yu: Mm-hmm) so all the different is involved in their, how they habit and where they feed and things like that.
For beetles, they have chewing mouthpart.
Ping Yu: Okay.
Shimat Joseph: So we call it biting and chewing mouthpart.
Ping Yu: Kinda like the mo- mosquitoes where they have the- Shimat Joseph: Mosquitoes, no.
Shimat Joseph: (laughs) Mosquito has a straw-like mouthpart.
Ping Yu: Oh, okay.
Shimat Joseph: Right?
So their body mouthparts are kind of developed into a straw (Ping Yu: Mm-hmm) inside we have needles.
Ping Yu: Yeah.
Shimat Joseph: So in, in mosquito, in this case, we have six needles in there.
Ping Yu: Oh, okay.
Shimat Joseph: That i- so when they do that, they basically insert these needles.
We call it stylets (Ping Yu: Mm-hmm) that's what we call it.
And they arrange this, uh, six needles in such a way that they can inject saliva into the system.
Ping Yu: Yeah.
Shimat Joseph: Could be a plant in...
or it could be [VERIFY: unclear term, sounds like "phytosis"] the cell tissue, and they pre-orally digest it and suck it up.
Ping Yu: Okay.
Shimat Joseph: Yeah.
Ping Yu: Okay.
Shimat Joseph: So they're basically munching it.
They are basically eating the tissue as such into their body.
Ping Yu: Okay.
Shimat Joseph: And that's how they're feeding.
So they have mandibles that's used for crushing it.
Ping Yu: Mm-hmm.
Shimat Joseph: They crush the tissue, and they basically ingest everything rather than, uh, digesting it pre-orally or anything like that.
Ping Yu: Uh-huh.
Okay.
So for the, a flea beetle, they have, like three pair of legs and one pair of antenna, and they're...
The main difference is that they have a, a hard shape- hard shell that can protect them from- (Shimat Joseph: Yeah.)
Shimat Joseph: That is true for all the beetles.
Ping Yu: Yeah, yeah.
Shimat Joseph: This is all true for all the beetles.
Ping Yu: Yes.
Now, back to the, uh, red-headed flea beetle specific, what, how, what kind of plant that they like the best the
most?
And are they chewing, like, flowers and- or, um, newly leaves or any, like, specific parts of the plant?
Shimat Joseph: Yes, that's a very good question.
For red-headed flea beetles, um, you know, has evolved the way that they can handle, um, the chemicals in the plant (Ping Yu: Mm-hmm) and the phytochemicals, and they can tackle
multiple plants in different families.
So we know that they can feed over 50 plant species, and that comes in different families.
Ping Yu: Mm-hmm.
Shimat Joseph: Okay?
So that kind of shows how versatile they are and their ability to tackle the toxics that's present, toxin that's present in the plant (Ping Yu: Mm-hmm) the phytotoxins.
So these insects are polyphagous in that way.
We call it polyphagous, poly meaning many.
Ping Yu: Mm-hmm.
Shimat Joseph: So they can eat many plants.
Ping Yu: Okay.
Shimat Joseph: And that's one reason this is a dangerous pest in ornamental system (Ping Yu: Yes) because when you go to nursery, you have all different plants and different families, and they are
have a capability to go and attack any plant that is present and still complete their life cycle.
Ping Yu: Mm-hmm.
Yeah.
Shimat Joseph: That's why they are seen as the most kind of serious problem in nurseries.
Ping Yu: Yeah.
Okay.
So can you give us some examples of the, uh, of the plant that they are feeding on and causing damage?
Like, I know, like they, you guys have done work on, um, um, hydrangea pa- paniculata, so I assume that's one of the ma...
I don't know if it's a major host plant or, uh, or just a, a normal host plant, but can you give us a little bit more, like, examples of
what kind of plants that do those pest (Shimat Joseph: Yeah).
Shimat Joseph: You're really right.
Panicu- panicled hydrangea, uh, that is paniculata.
Ping Yu: Mm-hmm.
Shimat Joseph: Hydrangea paniculata is one of the main one (Ping Yu: Okay) because we grow a lot of that now.
And at a, you know, it is a, it's a main crop for a grower.
Ping Yu: Mm-hmm.
Shimat Joseph: So if you go to any wholesale or any retail nurseries, this is a very wanted kind of plant now.
Ping Yu: Mm-hmm.
Shimat Joseph: So it is a high demand.
So that is a main major crop.
In addition to panicle hydrangea, they go after weigelas, forsythias, hollies, different kinds of hollies.
Ping Yu: Okay.
Shimat Joseph: But we see majority in, uh, Japanese ma- hollies (Ping Yu: Okay) a lot, Iteas, uh, sweetspire, Virginia sweetspire, whatever you call it.
So there are many, many sp- plants like that, but we see only this problem in container nurseries though.
So we did (Ping Yu: Okay) some work in the past where we were kind of wondering where they're coming from.
So in that time, there was a notion that they're coming from the landscape surrounding the nursery, and they're flying in, start feeding on the, the weeds that's grow on
the edges (Ping Yu: Uh-huh) the field, and they gradually come into the field, kind of an invasion kind of scenario.
Ping Yu: Mm-hmm.
Shimat Joseph: But we did our work, and based on our work, what we feel now is not, that's not true entirely.
Maybe it's happening to an extent, but it's not truly the major driver.
Ping Yu: Mm-hmm.
Shimat Joseph: Uh, it's major driver is the nursery itself.
They are in the nursery, and what we learned is that they like this environment that we provide as in a container.
So container itself is well-drained (Ping Yu: Mm-hmm) and water is not stagnant there.
It moves very fast.
And that environment that we provide is their favorite environment, and that's where they like to stay and grow.
That's why we don't see them in the...
When we did our samples in the landscapes, we didn't see them at all there.
So and we haven't heard red-headed flea beetle as a problem in the landscapes too.
So we are more told, uh, kind of, uh, ti- kind of thinking at the point is this is a problem, it's a nursery problem, container nursery problem, and not
in the landscape.
Ping Yu: Just because they, you, you guys believe that the, the red-headed flea beetle likes the container environment more often, more than the
landscape?
Uh, so back to your point, where does the plant come from?
Do you think it's already rested in the container itself or, or in the soil or...?
Okay, so you think it's in the soil.
Shimat Joseph: So this is a native, native species.
Ping Yu: Okay.
Shimat Joseph: So we believe that it's present in North America.
Ping Yu: Okay.
Shimat Joseph: Um, and they like water.
It is not dry conditions they won't do well.
Ping Yu: Okay.
Shimat Joseph: So the larvae has to be in the soil.
Ping Yu: Okay.
Shimat Joseph: So we know that, uh, they need a little bit wet conditions.
Ping Yu: Mm-hmm.
Shimat Joseph: And if you look at some of the crops that we grow, for example, cranberries (Ping Yu: Mm-hmm) cranberries in north, they grow in more wet, marshy conditions.
Ping Yu: Yeah.
Shimat Joseph: And they like that of conditions.
The same time they don't want like swamp conditions.
Ping Yu: Yeah, yeah, yeah.
Shimat Joseph: They want well too.
Ping Yu: Okay.
Shimat Joseph: They need level of drainness and the same time a moisture retention is needed for them to be successful.
Ping Yu: Okay.
Shimat Joseph: And I think the containers in the nurseries are providing exactly that, and they just love it and they just stay there and continue their population.
Ping Yu: So you think that the red-headed flea beetles are already in the, well, container nursery somewhere and resting and until the container
production system installed and have that f- have their favorable environment, which the, uh, which is kind of like a wet condition and they start to
survive and then become a problem for, (Shimat Joseph: Yeah.)
Shimat Joseph: Maybe it's waiting from a field situation (Ping Yu: Mm-hmm) somewhere and got into the nursery in the beginning.
Ping Yu: Mm-hmm.
Shimat Joseph: And as we do the trade and nursery production (Ping Yu: Mm-hmm) we move plant materials from nursery to nursery, region to region.
In that process, maybe they got spread everywhere.
Ping Yu: Okay.
Shimat Joseph: And they're basically using that as a niche, their niche habitat right now.
Ping Yu: Okay.
Shimat Joseph: And, uh, they're thriving there.
Ping Yu: Yeah.
So (instrumental music) So you kind of briefly mentioned the life cycle of this pest and they go through, um, they have the larval
stage and pu- the pupa in the soil and then they become adult.
Do you have the second instar or just like other, um, pest?
Or like can you give us a more like a brief introduction of its life cycle?
Um, what kind of conditions and then how long does the life cycle for the pe- for the pest?
Shimat Joseph: So it starts off with, uh, a-adults laying eggs.
Ping Yu: Mm-hmm.
Shimat Joseph: And they happen to be laying eggs inside the soil, so they can lay on the surface all the way down to like 10 centimeters deep.
Ping Yu: Oh, okay.
Shimat Joseph: Can go that deep.
So eggs are laid there.
Now, eggs will hatch into the first instars.
Ping Yu: Mm-hmm.
Shimat Joseph: The first instar larvae.
And the way things work is that insects grow inside the shell.
Ping Yu: Okay.
Yeah.
Shimat Joseph: And it's not like gradual like us.
Ping Yu: (laughs) Yeah.
Shimat Joseph: We are continuously growing, right?
Ping Yu: No, no.
Shimat Joseph: insects cannot do that.
So they are growing inside and when they get to certain size (Ping Yu: Mm-hmm) they shed the skin.
Ping Yu: Mm-hmm.
Shimat Joseph: They call it eclosion or, uh, not eclosion, the molting.
That's the word we use.
Ping Yu: Okay.
Shimat Joseph: So they molt because they get...
They lose that old skin (Ping Yu: Mm-hmm) and they make their own new skin.
Ping Yu: Oh, okay.
Shimat Joseph: In that process they increase the size, right?
Ping Yu: Okay.
Shimat Joseph: So we call it first instar, like first stage, whatever that is.
And they molt into another stage.
They look bigger.
Ping Yu: Mm-hmm.
Shimat Joseph: We call it like a second stage.
Ping Yu: Uh-huh.
Shimat Joseph: So we call it the second instar- second in this case.
Ping Yu: Okay.
Shimat Joseph: So I don't, we don't know exactly how many instars these beetles are undergoing, but we think that it's about three instars.
Ping Yu: Okay.
Shimat Joseph: So they go through three times like that, becoming bigger in size as they grow.
So three stages of development.
Ping Yu: Mm-hmm.
Shimat Joseph: Then when they get to a point where, uh, this is a ho-holometabolous (Ping Yu: Mm-hmm) that means these insects need to break down into something totally different (Ping Yu: Uh-huh) they look like
as an adult.
Ping Yu: Yeah.
Shimat Joseph: You know, it doesn't look same, right?
So larvae is not very resembling the adults.
Ping Yu: It's kind of like the how the, um, butterfly.
Shimat Joseph: Correct.
Ping Yu: The whole process of the butterfly.
Shimat Joseph: Exactly.
Ping Yu: Yeah.
Shimat Joseph: Exactly.
It's just like a butterfly in the monarch butterfly (Ping Yu: Yeah) might have seen in the butterfly gardens.
Ping Yu: Yeah.
Shimat Joseph: Same idea.
So larvae, they are in the root habitat.
That's where their habitat is.
Ping Yu: Mm-hmm.
Shimat Joseph: And they go to a stage when they're done with that, they completely go into a resting phase.
Ping Yu: Mm-hmm.
Shimat Joseph: Um, as to resting meaning they're not eating that point.
Ping Yu: Okay.
Shimat Joseph: They are just, uh, reconfigurating in there, changing into something else.
Ping Yu: Metamorph.
Shimat Joseph: They're changing into something different.
So they are doing that breakdown in a stage called pupal stage.
Ping Yu: Yeah.
Shimat Joseph: And after that they molt into a beetle.
They come out as a beetle.
They're totally different from the larval stage, right?
Ping Yu: Yeah.
Shimat Joseph: And that's why it's called holometabolous.
They're completely changing.
Ping Yu: Mm-hmm.
Shimat Joseph: It's not like same.
Okay?
So adults comes out and they sneak out from the soil.
Ping Yu: Mm-hmm.
Shimat Joseph: And they come out and they want to eat something.
They'll eat.
They try to find a mate.
They have to mate.
And all this process takes like six days, about six days.
Ping Yu: Mm-hmm.
Shimat Joseph: You know, they're, we don't know exactly how many days they need, take to mate or we don't know all those details yet.
But what we know is that within that timeframe they start feeding and also start mating.
And once that is done they're, they are ready to lay eggs.
Ping Yu: Mm-hmm.
Shimat Joseph: So that process again starts.
So their entire life cycle, that stage from egg to all the way to adult, it takes about one month (Ping Yu: Okay) in a summer day.
Ping Yu: Okay.
Shimat Joseph: In a summer temperature.
We are talking about 80, 85 degrees, uh, Fahrenheit.
Ping Yu: Mm-hmm.
Shimat Joseph: That's kind of temperature, but if it is cooler it take longer.
Ping Yu: Okay.
Shimat Joseph: So it's all temperature bond.
Ping Yu: Okay.
Shimat Joseph: How these things work at the end.
Ping Yu: But here in Georgia I would say, like, so do you think it's just about one month or s- at least southeastern part of the US would be, like, about
one month to complete their whole life cycle?
Shimat Joseph: Yeah, it can practically do it in one month.
Ping Yu: Okay.
So yeah, again, with the complete change phase, it's kind of like a caterpillar to butterfly.
They look exactly...
well, not exactly, totally different from the instar to the adults, right?
Shimat Joseph: Correct.
Ping Yu: So does...
You men- you kind of briefly mentioned that they also cause damage to the root ball as...
So those would be the instars, right?
Because when the adults, when they become adults, they were out there, not a- not in the surface of the soil, but out there looking for pests to
chew on, right?
Shimat Joseph: Correct.
I mentioned that the larval stage is feeding on roots.
Uh, the one thing remember, that we don't have any evidence of, uh, root feeding damage.
Ping Yu: Okay.
Shimat Joseph: They might be feeding the roots, but, um, out in a, in a nursery setting we are looking at roots (Ping Yu: Mm-hmm) and we didn't see anything so far.
So as a larval stage, when they feed on the roots, we don't have any economic damage to report.
Ping Yu: Yeah.
No.
Shimat Joseph: Anything to report, we don't care (laughs) really, because, uh, that's not impacting the, the sellability of the crop.
Ping Yu: Yeah.
People, people, people only see the plant itself, not the root yet.
Shimat Joseph: Yeah.
Ping Yu: Right.
Shimat Joseph: Right.
Ping Yu: Yeah.
Shimat Joseph: But as adults they are destructive, because that is destructive stage, economically important stage of that pest.
Adults feed, and they cause damage, and doesn't care whether it is a freshly new leaves are coming out or it's old leaf.
They can feed on both alike.
Ping Yu: Oh, so they can feed on all the leaves.
Shimat Joseph: Correct.
Ping Yu: Doesn't really matter if it's newly leaves or older leaves.
Shimat Joseph: Correct.
Ping Yu: But they don't feed on...
They don't damage the flowers yet, right?
Shimat Joseph: Well, they can feed, but we haven't seen any damage, so you're right, on the flowers.
They are primarily leaf-feeding beetle.
Ping Yu: Okay.
Shimat Joseph: And that's what...
This is coming from a group of family that's called Chrysomelidae.
Ping Yu: Mm-hmm.
Shimat Joseph: And that's basically categorizes leaf-feeding beetles.
Ping Yu: Okay.
Shimat Joseph: And that is very abundant group, and there is all different kinds of, uh, insects there.
One...
another pest you might be familiar with is Japanese beetles (Ping Yu: Oh, yeah).
yeah in Southeast.
So that, that's another leaf-eating beetle.
Ping Yu: Okay.
So, so we kind of categorize those beetles with their feeding source.
Shimat Joseph: Yeah.
Ping Yu: Um, if it's a leaf-feeding, so this, this pest specifically belongs to the leaf-feeding beetle category.
Shimat Joseph: Yeah.
Ping Yu: But Japanese beetle can feed on flowers too.
Shimat Joseph: Oh, yeah.
They feed on flowers.
But in this case we haven't seen them attacking any flowers or in particular.
Ping Yu: Okay.
Shimat Joseph: They might be feeding it, but we haven't seen it.
Ping Yu: (instrumental music) So I know another fascinating or interesting fact of the pest that, that I, at least
I, uh, have been learned, that is that, uh, some of the pest, they are...
I don't know if that's true, but I feel like the male and female, uh, like in the pest world, a lot of times the male is only there
to mate, and after that they're gone.
Is that right for the red-headed flea beetle as well?
Shimat Joseph: Honestly, I don't know.
(laughs) That's the truth.
But if I guess, I would say, uh, not so much, because males, you're right, they're for mating.
That's the main job.
Ping Yu: Mm-hmm.
Shimat Joseph: But they're definitely going to feed too.
Ping Yu: Okay.
Shimat Joseph: Um, and we have seen males feeding and females feeding alike.
Um, and, uh, I don't know how fu- or how long they feed as that, in that stage, uh, but definitely males feed.
Ping Yu: Okay.
Shimat Joseph: There's no doubt about it.
Ping Yu: But so in terms of like, in terms of the population of the male and female, do you have any idea of like what is the ratio of the,
uh, male and female out there in the field, uh, like what, what kind of ratio?
Shimat Joseph: Ho- honestly, I don't know that too.
That needs to be researched.
(laughs) So whatever we know at this point is that, uh, we are thinking that they are one is to one, but, uh, you know, I...
we can't really say for sure.
Ping Yu: Okay.
Shimat Joseph: If there is any other, you know, endosymbionts, we say some of the gut, uh, bacteria that is (Ping Yu: Mm-hmm) very specific and driving the females are more.
Ping Yu: Okay.
Shimat Joseph: We don't know all those things exist in this beetle.
We haven't done any work on that area as well.
So there is a lot of work needs to be done.
Ping Yu: I know, 'cause, uh, as we were talking I was like, "Hey, what about this?
What about that?"
'Cause I don't, I don't know any of those answers, and I saw that y- as a researcher you might know more of those.
But then, so that's w- I think one of the fascinating fact of academia, of research, is the way...
there's always so much unknown.
I guess that's our, the security of our job, right?
(laughs) That's So for the, um, for the, uh, red-headed flea beetle, so basically both male and female are feeding the plant
and...
but how many eggs do you know a matured female will lay each time?
Shimat Joseph: That's a very good question.
Again, I don't have an answer for it.
Ping Yu: (laughs) Right.
Shimat Joseph: I'm asking all those research questions so that we need to do work on that- and to solve those, to answer those questions.
There are many basic questions we need to know about this pest (Ping Yu: Mm-hmm) we don't know.
We can guess it, but I think the guessing may not be right here.
So that's why I'm not giving a number to it.
But, um- they might...
They are...
They...
We don't know how many eggs they lay, how long the adults live.
Ping Yu: Mm-hmm.
Shimat Joseph: We don't know how many times they mate, when they mate.
We don't know a lot of, uh, basic biology (Ping Yu: Mm-hmm) of this pest yet.
Like I said, when I walked into this pest, uh, studying this insect, uh, like, uh, eight years ago (Ping Yu: Mm-hmm) because the growers were having (Ping Yu: Mm-hmm) problems with that.
So my goal at that point, and still, is to try to manage it, and we didn't, uh, we didn't do much work (Ping Yu: Mm-hmm) in understanding their biology a lot.
Ping Yu: Okay.
Shimat Joseph: we are interested to do that.
Uh, hopefully with time we'll learn more this.
Ping Yu: Yeah.
Because those are very, like, fundamental information about this pest and then I would think that from the research perspective, if we know those answers,
it might provide us with more information for us to better control them because we can interfere, um, their life cycle at different stage and say,
what is...
wha-what would be the best time to interfere that and then make the best management tool for that, right?
Shimat Joseph: Yeah.
That's right.
Ping Yu: (laughs) Uh, so for the red-headed flea beetles, when would you think it'll be for the growers?
When would be their peak season that would...
they would cause the most damage for the plant?
And is that in the summer or what, what's the, what's the thought in there?
Shimat Joseph: That's good.
Good question.
So we, uh, when we started this, about studying this pest, this with our...
Those, these were our basic questions.
Ping Yu: Mm-hmm.
Shimat Joseph: When they are there, what is that, uh, what stage is present and what time?
Ping Yu: Mm-hmm.
Shimat Joseph: And, uh, you know, how long they will remain like that, and is that a problem throughout the year?
So my graduate student basically addressing all those things.
Ping Yu: Mm-hmm.
Shimat Joseph: So he was trying to understand the phenology of this insect.
So like, um, uh, how many generations are there in this year?
Ping Yu: Mm.
Shimat Joseph: So we are just asking one question a step, one question at a time, and this is one question we asked.
Try to understand how many generations.
Based on his work, I think we have four generations, and that's basically that we understand.
And, um, what was your other question?
Ping Yu: Yeah.
Um, and we-we do...
There's a word that called scouting for people who goes to-- goes out and looking for pests and then take actions to prevent it from getting worse.
Shimat Joseph: Right.
So we start, uh, in our case, in Georgia (Ping Yu: Mm-hmm) and mostly maybe a little variation in going north.
We start seeing their adults coming in in May.
Ping Yu: Okay.
Shimat Joseph: So in first to second week of May, we start seeing them, and, uh, once we, uh, the growers at this point, they all use visual means to, uh, see
whether the beetles are out or active (Ping Yu: Mm-hmm) feeding.
Um, we don't have a trap, uh, anything like that.
Like I said, there are many areas that (Ping Yu: Mm-hmm) need to study about this pest.
Uh, we don't have a lot of answers to all those things.
But still, the, the method right now is look for adults, and if you see any damage, that's kind of indication that you need to make an application.
Ping Yu: Mm-hmm.
Shimat Joseph: And in our case, it is about first to second week of May (Ping Yu: Okay) we see the first peak emergence of adults happens.
After that, it'll stay about a month or so like that as an adult activity, and with time, you will adult activity go down.
And, uh, in that time, basically all laid eggs and there's larvae going on at that time.
And we have a gap in June.
And after that, in July, then we'll see a second generation coming in.
And after that, you know, we'll see a peak.
Then after then, there is so much, uh, you know, y- you know, depending on who came early and who (Ping Yu: Mm-hmm) came late in May.
There is a egg-laying process and a differentiation in, uh, egg laying and development happens in the c- in the containers.
Ping Yu: Okay.
Shimat Joseph: In that way, the, there i- there eventually with the third, second generation, you start seeing an overlap in generation.
Ping Yu: Okay.
Shimat Joseph: So then we can't really pinpoint, okay, this is a third or second.
We can't really tell (Ping Yu: Okay) because it becomes so overlapping at that point.
So third and fourth is always like that.
Ping Yu: Okay.
Shimat Joseph: It's, it's very difficult for us to...
Another aspect that we are finding is the host plays a big role.
Ping Yu: Mm-hmm.
Shimat Joseph: You know, some hosts support them, uh, development very quickly and others are not.
And we see that, uh, across the board, and, uh, when we think about management, that's why this is a very difficult pest to manage.
It's not like we developed a grow- growing degree day model and say how much heat they accumulate, and we say, "This is the time to apply."
It is not as easy as that because the hosts and when they come, uh, in the gre- in the nurseries all plays a big role in what eventually happens
in that nursery.
Obviously, it kind of falls out in the rest of the season.
So it is complicated because of that, and that's why this is a very difficult pest to- Ping Yu: Yeah, 'cause I was thinking about, like, if the first w- or if
Ping Yu: the scouting starts, well, in May where-- and people will start to see the damage, and then that's when they need to start a spray or take management tools
to manage it.
S- Speaking of that, I h- I know that you guys have done a lot of work in trying to manage this pest.
Are there any effective method that you c- will give the grower or whoever who wants to, uh, manage this pest and give
the outline of how to manage it effectively (Shimat Joseph: Right) with your knowledge?
Shimat Joseph: That's right.
So going back to what you just said about there, how complicated it is.
It, it is complicated because it's not just a distinct generation.
Ping Yu: Yeah.
Shimat Joseph: We are also talking about space in the nursery and how the plants are kind of spatially distributed.
Ping Yu: Yeah, yeah.
Shimat Joseph: And their ability to feed on multiple hosts, and that basically complicates how we're gonna manage it.
So we have taken multiple approaches to really tackle it.
So we ti- uh, we try to, uh, focus on adults first because that's more economically important pest (Ping Yu: Mm-hmm) stage of the pest, sorry.
Ping Yu: Mm-hmm.
Shimat Joseph: And that's what they...
we targeted first.
So we did some several studies (Ping Yu: Yeah) to understand and screened a few important ones that growers can use.
Um, for example, neoni- if a grower is u- using neonicotinoid insecticide spray, that is a very good insecticide.
That is, uh...
that can be used for managing this pest.
Other insecticides like Sarisa (Ping Yu: Mm-hmm) is a cyclaniliprole, and that product.
XXpire is another one.
So there are many other insecticides that we found, like handful of insecticides that can be used.
There is a new one that is plinazolin that's coming.
It is on the pipeline.
Ping Yu: Okay.
Shimat Joseph: So I hope it'll be coming, and it's all very effective products.
So there are some tools, not a lot.
Ping Yu: Yeah.
Shimat Joseph: There is some tools that they can use as a foliar spray.
We also interested in tackling the larvae.
Ping Yu: Mm-hmm.
Shimat Joseph: So we went with the drench applications.
Ping Yu: Yeah.
Shimat Joseph: And there is handful of insecticides that we can use.
Again, some of them are also labeled to use as a foliar, so that is a challenge here.
So when you come up, uh, with the managing this pest needs to be a multi-pronged approach.
Ping Yu: Mm-hmm.
Shimat Joseph: It is not like one foliar spray here on this crop will take care of it.
Ping Yu: Yeah, because it does h- the-- both the larva and adults can cause damage to the plant.
Shimat Joseph: Not necessarily the larva stage causing the damage (Ping Yu: Mm-hmm) the adults can move to other plants (Ping Yu: Yeah) and still stay there and complete a generation there, and you might be
not having a cro- any problem in the, in the crop that you sprayed (Ping Yu: Yeah) but they are going to come back.
Ping Yu: Yeah.
Oh, yeah.
Shimat Joseph: So, so it, it should be a, a kind of a, a strategy where we ta...
we are doing both the application methods in such a way that, that we can suppress the population.
And that's kind of a area that I'm trying to, trying to develop a program or trying to come up with a strategy.
Right now I'm not there yet because I need to know how they are, they're moving, how they are behaving with different hosts, and all those things still need to
be known.
But right now, what really works is a drench application if...
or a granule application of neonicotinoid insecticide.
Ping Yu: Mm-hmm.
Shimat Joseph: If that is...
If the nurseries is willing to do that.
If they do, they can do that early the year, uh, in the season, like sometime in April.
If they can make those application, it will, it will have insti- residues, insecticide residues on the plant.
Ping Yu: Okay.
Shimat Joseph: In the plant, so adults can be stopped.
Not necessarily the larvae here.
We can stop the adults from feeding.
Ping Yu: Mm-hmm.
Shimat Joseph: And we know that it can go multiple months like that (Ping Yu: Oh) give a protection.
Ping Yu: Okay.
Shimat Joseph: It is good enough that different growers can strategize that according to their marketing window.
Ping Yu: Mm-hmm.
Shimat Joseph: Because there is a spring window, early summer window (Ping Yu: Yeah) there's a gap there, then it's another window starts.
Ping Yu: So growers need to star- strategize their, their use of insecticides (Shimat Joseph: Mm-hmm) management, management, uh, strategies based on their selling points (Shimat Joseph: Mm-hmm)
at the window where they're going to sell all the crops.
Shimat Joseph: Yeah.
Ping Yu: Kind of following up on what you just said, what...
There's a lot, still a lot of unknowing about this pest and then because of the complication of the pest and, um, the relationship between the pest and the plant
itself.
What is your next step of the pest, of, of managing the pest?
Let's put it that way.
Shimat Joseph: Yeah.
So we want to know, like I just said, I really not need to know how they behave in the nurseries.
You know, one thing my other graduate student is working on is when we spray a block of plants like hydrangea, a block of plants, you can get the protection
from this beetle to that block.
But eventually what happens is that they're, they're-- we are pushing them to other plants and, uh, where they normally won't go.
Ping Yu: Yeah.
Shimat Joseph: And we want...
We are trying to understand what is that their behavior.
Are they going to go there or lay eggs there or not?
Those kind of things we are going.
So how they move within the nursery with the complication that, uh, the host itself, and also how they manage it currently.
Ping Yu: Mm.
Shimat Joseph: Because they can't afford to spray the entire nursery same time.
Ping Yu: No.
Shimat Joseph: They cannot do that.
It's very expensive.
Ping Yu: For those who doesn't know, like, chem- chemicals or insecticides are super expensive.
Shimat Joseph: And labor.
Ping Yu: Labor is also (Shimat Joseph: Yeah).
Oh, yeah.
Shimat Joseph: Yeah so we are-- that could be-- uh, that is one area that we want to figure out.
Okay, what is the best way to go?
What host they prefer as adults and also for laying (Ping Yu: Mm-hmm) egg laying.
That is another area that we are working on.
So my graduate student's also working on that.
Ping Yu: Mm-hmm.
Shimat Joseph: So we are basically working on different projects and different, uh, pieces.
Ping Yu: Mm-hmm.
Shimat Joseph: And idea is that maybe in couple of years we might be able to pull everything together (Ping Yu: Mm-hmm) and make a sense what's going on.
Ping Yu: Okay.
Shimat Joseph: Because we really don't know, uh, what is really, really going on right now.
Because, um, as an adult they can feed on many things.
As a, a laying eggs, what they prefer.
Ping Yu: Yeah.
Shimat Joseph: Um, so we need to know that.
Because X and Y host, probably they are not feeding.
Ping Yu: Yeah.
Shimat Joseph: maybe they're using as a host to lay eggs.
Ping Yu: Yeah.
Shimat Joseph: We don't know that part.
So there are a lot of questions still there we need to understand before we come up with and say something comprehensive or something like a recommendation.
Ping Yu: Yeah.
I kind of love my job with ornamentals, but also it's a pain as well because things can get very complicated in terms with ornamental and, uh, and then the
ornamental relationship with or the crop relationship with, like, the micro-- uh, mi- microbes and, uh, the pests and then pollinators and all other, uh,
things that goes within the whole world of the, of the, uh, crop.
(gentle music) Uh, so now let's move back to the main focus here.
If as a...
You, you do have extension appointments, so if a young grower come into you and say, "Hey, Dr., uh, Joseph, I want to set myself up
for long-term success," what kind of information or what kind of suggestions you would have for them?
Shimat Joseph: That's a good question.
So let me talk in the context of the flea beetle contest.
One thing that they can do is when they move plants into the nursery, they might be buying a plant material or whatever, make sure you just isolate it somehow.
Ping Yu: (chuckles) Oh, yeah.
Shimat Joseph: From your- (Ping Yu: Quaran- quarantine) That's the thing.
Ping Yu: Yeah.
Shimat Joseph: So, you know, we, we worked with this flea beetle, and we tried to do some kind of fencing where we had a overhang inside so that the beetles cannot
move from that area.
So bring the plants-- When you bring new plants into the nursery, watch for the plants really carefully.
Don't put it, unleash it into the (Ping Yu: Yeah) into your main area because we want to watch it.
And, uh, if you can give a, uh, you know, if you see any insects there, that's basically the time to watch that.
Any activity, monitor them for any insect activity.
If you see something there, uh, you might need to make an application and make sure you give, uh, some precautionary treatments before you move into or put those plants
into other areas.
You know, it's very easy to say because very-- it is often challenging for- Ping Yu: Because i- in terms of, like, doing that for growers and they want
Ping Yu: to-- they are sacrificing their space and labor to have a separate space for that plant.
Shimat Joseph: Yes.
Ping Yu: And that's money (Shimat Joseph: Yes) and effort in there.
So for anyone who's out there, go to the, um, big store and grab something.
You think that's just a, a plant from the, from the, um, Home Depot or, uh, Walmart.
It's not just that.
There's a lot of going on behind the scene where the plant is growing, and they have all those interactions with the pest, and they have to combat the whole
challenges to be able to come to your door.
Shimat Joseph: Right.
Ping Yu: So, um, just, um, just in general, just be appreciate with the plant that you are buying and then, um, for that.
Shimat Joseph: Sure.
Ping Yu: So with that, are there any other last comments, yeah, you wanna leave for our audience?
Shimat Joseph: That's basically it.
(chuckles) Just, uh, keep, uh, following us.
Ping Yu: Yeah.
Shimat Joseph: You know, in years come probably we'll have more research coming in.
Ping Yu: Mm-hmm.
Shimat Joseph: So once we get all those work done and published, we might have some, uh, recommendations and guidelines (Ping Yu: Yeah) for growers to use.
Ping Yu: And don't worry, I'll have Dr. Shimat Joseph coming back to the show in the future, uh, give us updates.
So with that in mind, if people wants to keep a finger on the pulse of what you are doing, following along with the work, where do you recommend they
go and to look out for and find out, find out more?
Shimat Joseph: That's great.
So I, i- within University of Georgia, we have a department website.
Ping Yu: Mm-hmm.
Shimat Joseph: And, uh, we-- if you go there, you know, you should see all the faculty members listed.
Ping Yu: Yeah.
Shimat Joseph: And my name is also listed in there.
Ping Yu: Yeah.
Shimat Joseph: So if you go there and click my name there, there should be a page op- kind of opening up.
Ping Yu: Mm-hmm.
Shimat Joseph: That kind of lists, uh, uh, the publications that comes out- from my lab.
Like I said, I- my work is more applied and more practical as much as possible that I always try to be like that, so that is useful to people
right away.
Ping Yu: Yeah.
Shimat Joseph: And, uh, we also have a, uh...
In that website, you'll see all the list of publications.
Ping Yu: Mm-hmm.
Shimat Joseph: And we also have a blog.
And I would just say please sign up for the blog.
And, uh, uh, w- we write any new things coming up, you know, any new findings that we find on different insects.
Ping Yu: Mm-hmm.
Shimat Joseph: We write blogs.
And, uh, if you sign up and subscribe in that (Ping Yu: Yeah) know, there is small three boxes there with an email address and your name.
Ping Yu: Mm-hmm.
Shimat Joseph: You should get an email with any new updates, and that's one, one way to get in touch.
Ping Yu: (laughs) Thank you so much.
Uh, I thank- thank you, Dr. Shimat Joseph, for taking time out with his, uh, from his, um, b- busy schedule and talk, talk with us today.
So as always, um, go...
I'll put the...
I'll try to put the show notes in the, in the, uh, website, and then, uh, you can find more about his topic and his work.
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