Ping Yu: 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? I'm doing great because I have one of the icons of the greenhouse pest management, entomologist

Ping Yu: and researcher Dr. Lance Osborne. Lance has been working on pest management research for years and I had the privilege of knowing him when I was doing my postdoc work at University of Florida, MREC. In today's episode we are going to pick his brain on spider mites and better management practices for greenhouse crop production.

Ping Yu: So I don't want to steal any more thunder from our speaker today.

Ping Yu: Without further ado, here is my conversation with Dr. Lance Osborne.

Ping Yu: I hope you enjoy it.

Ping Yu: Hi, Lance, welcome to the podcast.

Ping Yu: But first, let's start off with the introduction.

Ping Yu: Can you tell our audience a little bit about who you are and what you do?

Lance Osborne: Hey, my name's Lance Osborne. I'm at the Mid-Florida Research and Education Center, which is near Orlando, Florida.

Lance Osborne: I've been here for almost 45 years, 46, something right. Who's counting anymore?

Lance Osborne: But I came from California, graduated from UC Davis.

Lance Osborne: I did quite a bit of work in their greenhouses and ornamental department, working on biological control of insect pests and mites.

Lance Osborne: I did my PhD on the greenhouse whitefly and biological control using Encarsia formosa.

Lance Osborne: I did a postdoc on mosquitoes, which I was glad to get a job back in greenhouses.

Lance Osborne: It's no fun going out every morning collecting 10,000 mosquitoes off of my leg.

Lance Osborne: So then I've been here ever since.

Ping Yu: Wow.

Lance Osborne: I enjoy working and get up every day to come to work.

Lance Osborne: Some days it's more playing than working.

Lance Osborne: So good job.

Ping Yu: I remember seeing you every morning when I was at MREC back three years ago and I was like, I go to work every day and I was like, Lance is here every day.

Ping Yu: But do you see yourself growing up as a nature kid or are you interested in the beginning with pests when you were a child or is this something

Ping Yu: that stumped us through your education to this trajectory?

Lance Osborne: I was kind of a wild kid. My parents let me run out the door in the morning in Florida, where I grew up in Cape Canaveral. And so I'd run around for the whole day doing whatever.

Lance Osborne: I really got interested in insects just as a kid. I had friends that took entomology as a— I basically collected all their collections for them.

Lance Osborne: And then I went to UC Davis, and I was in pre-vet, but I couldn't stand the blood and gore.

Lance Osborne: And so I started working on other things, and they were all going extinct.

Lance Osborne: So I started working on insects, because I knew I wouldn't have to worry about losing them.

Ping Yu: That's a good shift of all those extinct things that you ended up with insects.

Ping Yu: So basically you grew up in Florida and you went to school in California and then come back to Florida for your job.

Ping Yu: What is the big difference? Like you having lived in both states, what would be the biggest difference?

Lance Osborne: Florida's a zoo. You go outside and there's stuff crawling around everywhere. There's probably more going on than any one person can handle. It's fun, but sometimes you lose, if you're like me, the OCD. I keep going from a short attention span. I go from one thing to another. That's why I love my job. There's always something to work on. There's always something new.

Ping Yu: Yeah, you're right. And especially in the ornamental world, we're dealing with thousands of different plants. With the pests, I know there's countless work that can be done. So I guess it's a job safety, too, or job security. All those pests that you have worked with, if you had to pick one, which one would be your favorite?

Lance Osborne: I don't know if I can say I have a favorite.

Lance Osborne: I like working with spider mites and mites in general, but I kind of lean toward white—

Lance Osborne: flies as being the one that I like the most.

Lance Osborne: But spider mites basically was what I was hired to do.

Lance Osborne: Even though I did my PhD on whiteflies, I was told that I'd never work on whiteflies ever again when I came to Florida.

Lance Osborne: And why is that?

Lance Osborne: They said they just didn't see them.

Lance Osborne: And basically five years later, I've been working on whiteflies, a bunch of different whiteflies ever since.

Lance Osborne: I didn't bring them.

Lance Osborne: I didn't bring them to Florida, I swear.

Ping Yu: People would blame you, say, hey, before you came here, we don't have whitefly issues. Now all of a sudden we have all those whiteflies coming to Florida.

Lance Osborne: It's just because somebody was here looking for them.

Ping Yu: You're right. You're right. I know Florida because I lived in Florida for about a year and Florida has its unique environment which is good for a lot of plants, but also a heaven for the pests, I would say that.

Ping Yu: What is the top pest challenge in greenhouses in Florida specifically?

Lance Osborne: The challenge is that if a grower is going to try to save money and be able to grow a healthy crop, he's got to pay attention to spider mites. So it's the foundation of an IPM program had to be something that could manage spider mites. And that was the truth nationwide.

Lance Osborne: There was a study done out of Georgia with Will Hudson that basically said spider mites were the most sprayed pests in ornamentals nationwide.

Lance Osborne: More chemicals went out.

Lance Osborne: So that was a logical place to start in trying to develop an IPM program.

Lance Osborne: And then as you start picking off one pest at a time, you start getting all these other ones that come in when you reduce the pesticide pressure.

Lance Osborne: And so then we went from one to another and it's been an ongoing saga ever since.

Lance Osborne: But we have very good management programs for spider mites.

Ping Yu: Yeah, I know spider mites and pests and plants are similar to...

Ping Yu: human being, we would adjust to a certain environment. If the environment is their favorite place, then they would just survive in there. And do you think that Florida is providing the favorite environmental condition for spider mites to survive in that regard. I mean, like you said, spider mites is everywhere in greenhouse, but specifically in Florida. Do you think that Florida provided a better environment for them to be a bigger problem?

Lance Osborne: I think they are allowed to, because we have a year-round nice accommodating temperatures and environments so that you don't get a break in the life cycle like you do as you move north and get colder and actually have freezes.

Lance Osborne: We don't have mites go into diapause here.

Lance Osborne: And so we don't see the red version that everybody keeps talking about.

Lance Osborne: I haven't seen one in Florida.

Lance Osborne: But again, they prefer it hot and dry, which is kind of— we're not hot, dry.

Lance Osborne: We're plenty hot, but not dry.

Ping Yu: Yeah.

Lance Osborne: So, I mean, but nationwide.

Lance Osborne: Mites are a major issue in greenhouses.

Ping Yu: Because you kind of briefly mentioned the life cycle in Florida, they don't take a break.

Ping Yu: But can you elaborate us a little bit more specifically for spider mites?

Ping Yu: What are their life cycles?

Lance Osborne: Okay, well, basically you have the egg, you have a larval stage, you have a protonymph, and a deutonymph. I haven't memorized its life cycle that well. Mainly working on whiteflies, so I forgot some of this stuff. But the bottom line is you go through a number of different immature stages.

Lance Osborne: And they molt to become an adult, depending on temperature. The temperature drives how quickly the mites progress through all these stages. And so we can have a life cycle that you can have a generation in about two weeks.

Lance Osborne: Okay, so they can really develop quickly.

Lance Osborne: And as it gets colder, it can be up to 40, 50 days.

Lance Osborne: So it just depends on the temperature.

Ping Yu: Yeah, because I was pulling stuff up here.

Ping Yu: Five different stages, from egg, larva,

Ping Yu: protonymph and deutonymph, I don't know if I pronounce it right.

Ping Yu: Yeah, and then adult.

Ping Yu: Two weeks is pretty short for them to finish the whole life cycle.

Ping Yu: So they can reproduce really fast.

Ping Yu: Well, I guess one of the big issues for any of the pests, and if you wanted to manage them, you would know which stage that they are most devastating for plants were.

Lance Osborne: Well, I mean, the adult's going to be able to do the most damage.

Lance Osborne: because it's bigger. Basically, they penetrate the cells, remove the fluids, and that cell dies.

Lance Osborne: And so you get little yellow marks and stippling. And as they feed on it more, the yellow spots get bigger. They coalesce. And so you can see the population growing just by looking at the yellow. As you get larger mites, they just feed on a lot more cells, and so the spots get bigger.

Lance Osborne: And generally, where there's one adult, there's going to be a whole lot more.

Lance Osborne: So they can cause damage very quickly.

Ping Yu: But among all those five stages of the life cycle of spider mites, only the adults cause damage to the plants?

Lance Osborne: Even the very young ones will do a little bit of feeding. So they all cause damage. It's just that I do more damage on eating the steak at my house than my kids do.

Lance Osborne: Because I'm bigger.

Ping Yu: Okay.

Ping Yu: So for the larva and the two nymphal stages, it still causes damage to the plant, just not to the extent of the adult does, right?

Lance Osborne: Yeah, that's correct.

Lance Osborne: And each of those stages, just before they molt to another stage, they have a resting stage.

Lance Osborne: which doesn't feed.

Lance Osborne: So their whole time as a larva or a deutonymph or protonymph has got half of its time in a resting stage, molting and developing to the next stage.

Ping Yu: And how long does that stage last?

Ping Yu: A day or two or...?

Lance Osborne: It depends on which ones, and again, it depends on the temperature.

Ping Yu: So do all those stages of the spider mites live on the plant leaves, or do any of them live in the soil?

Lance Osborne: None in the soil.

Lance Osborne: Okay, most of the mites are found on the plant.

Lance Osborne: They prefer to be on the underside of the leaf.

Lance Osborne: But that doesn't mean that as the populations grow, under pressure, they may move on to the top of the leaf.

Lance Osborne: Yeah.

Lance Osborne: And as the population gets really high and the plant's starting to suffer, they will

Lance Osborne: develop webbing and basically as a mechanism to disperse from that plant that they perceive as probably going downhill.

Lance Osborne: So they can be carried by the wind on these strands of silk.

Lance Osborne: These strands of silk can get on people's clothing.

Lance Osborne: So then if you brush against them, you're going to transmit them to someplace else in the greenhouse.

Lance Osborne: or a pet, another animal— they can hitchhike.

Lance Osborne: But it's mainly the silk is a way that they help transfer themselves from one plant to another.

Ping Yu: Okay. Yeah, yeah, yeah.

Ping Yu: Because I know that for spider mites, I guess that's the late stage of the spider mites when the population has already built up so quickly.

Ping Yu: And so you can start seeing the web now.

Ping Yu: But that will be too late for people to take any actions to control the pest, right?

Lance Osborne: Yeah, it depends.

Lance Osborne: If you really don't mind, you're going to have damage on that plant.

Lance Osborne: It's not going to go away.

Lance Osborne: So if it's gotten to that point, you might as well, if you want to sell a quality plant, you might as well dump it.

Ping Yu: Yeah.

Lance Osborne: But if it's your pet plants in the house, you probably do what you can to save it.

Lance Osborne: So it just depends on what your goals are.

Ping Yu: Yeah.

Ping Yu: So you kind of mentioned that the pest normally would stay in the lower side of the leaves.

Ping Yu: So that's where people, if people are scouting for the plant, that's where people should be looking for, right?

Lance Osborne: Yep, they should be turning leaves over and looking at the bottom of the leaves.

Ping Yu: And what exactly should they be looking for?

Ping Yu: What is the first sign of the spider mite?

Ping Yu: Some of the first or early symptoms that people would start getting their eye on the pest?

Lance Osborne: I think they'll probably see the yellow stippling on the top of the leaf first.

Lance Osborne: But it depends on how good you are at looking at things.

Lance Osborne: You have, and this is a problem I have with a lot of trade shows, that these people pick up the small plastic hand lenses.

Lance Osborne: They're not good enough, okay?

Lance Osborne: Especially nowadays when we're dealing with broad mites and thrips parvispinus, chilli thrips.

Lance Osborne: You need a good hand lens.

Lance Osborne: It's worth the investment.

Lance Osborne: It's going to cost you $40, $50, but it's something you can use, and you can actually see something.

Lance Osborne: And then you can see the adults. You will see often the eggs may be laying around. You'll see these little round, spherical, opalescent white eggs on the underside of the leaf. They look like they may be floating because they're on some of the webbing.

Lance Osborne: And that's again another telltale sign.

Lance Osborne: You may see dead bodies laying around, especially if you have a predator.

Lance Osborne: The predatory mite will remove the fluids and you'll see these little bodies laying around.

Ping Yu: What are the host range for spider mites?

Ping Yu: I know that they can cause damage to a wide range of plants.

Ping Yu: What are the main ones that are most susceptible to spider mites in the greenhouse setting?

Ping Yu: Yeah.

Lance Osborne: It's like which ones aren't. Croton is one. Dieffenbachia is one. Gerbera daisy. We get a spider mite I think it's called Lewis mite on poinsettia. So it depends on the host plant. We get spider mites. They're always on hibiscus. In the greenhouse and for maintaining colonies of things, we often use beans, lima beans. So they get on a lot of different vegetables. The solanaceous crops, you will get a different— Tetranychus evansi, which is a little tiny mite that feeds on tomatoes and eggplant, and they're a reddish color.

Lance Osborne: So if I have a plant, I can probably get a mite to go on it.

Ping Yu: So basically, I guess they would have their favorite, but they generally feed on any ornamental plant in the greenhouse, and maybe that's one of the reasons why they're the top one challenging any of the greenhouse nationwide.

Ping Yu: For people who were able to, let's say, they were able to spot the first sign of the spider mites from their scouting process.

Ping Yu: What should they do next?

Ping Yu: They need to take actions.

Ping Yu: What are some of the effective management practices that they need to take on, especially if they're a good grower, they can spot on those early signs of spider mites.

Ping Yu: What should they do?

Lance Osborne: Okay, well, the first thing is...

Lance Osborne: So our growers need to, basically, I think they need to make sure they know what they're fighting.

Lance Osborne: Okay.

Lance Osborne: Some of the guys that have been working a few years know exactly what spider mites are and don't really need to do much more than that.

Lance Osborne: Then if it's a really bad infestation, trying to cure...

Lance Osborne: A lost cause is just a waste of time and money and puts everything else at risk.

Lance Osborne: So get the really nasty ones out of the greenhouse, destroy them, make sure they get someplace that it's not going to reinfest your greenhouse plants.

Lance Osborne: Then you kind of try to scout to see how far it's spread, how wide of an area do you need to treat.

Lance Osborne: Is it just a few plants or do you have to treat everything in the greenhouse?

Lance Osborne: Whether you're going to use a chemical and treat the whole nursery or spot treat, or whether you're going to go another route and get biological control.

Lance Osborne: It just depends on the level that you're dealing with.

Lance Osborne: If it's a few mites, you might be able to get a biocontrol program.

Lance Osborne: But once they're really well established, you need to drop the population back and start from the beginning.

Ping Yu: So what are some of the chemical or effective chemicals that can be used for spider mites treatment?

Lance Osborne: Well, that—I could have somebody standing here, somebody next door.

Lance Osborne: Ask that question, and the answer is going to be different for both of them, because you can have localized populations where they're resistant to pesticides, and they can be even almost in the same greenhouse.

Lance Osborne: So there's no magic bullet.

Lance Osborne: I can recommend a few that I think work well, but you have to try.

Lance Osborne: That's where your scouting comes in, is that you need to go to the spot where the mites were after treating and ascertain whether your chemical is actually doing what you think it's supposed to be doing.

Lance Osborne: And so you have to have a good scouting program.

Lance Osborne: You have to stick with it so that you make your application and you go back to those plants.

Lance Osborne: And it depends on the chemical.

Lance Osborne: For example, Avid, people used to say it wasn't working.

Lance Osborne: They go through and they spray and they come back the next day and there would be some live mites.

Lance Osborne: Some of them don't die or they don't shrivel up and turn brown.

Lance Osborne: So with Avid, they'd be sitting there, they'd look like they're healthy. But they're a little bit raised up on their, like on stilts.

Lance Osborne: And you could touch them and they'd fall over like tipping cattle.

Lance Osborne: They just fall over.

Lance Osborne: They don't do anything.

Lance Osborne: They look healthy.

Lance Osborne: They didn't dry out.

Lance Osborne: So it's like they were encased in plastic or something.

Lance Osborne: Some don't, will take seven days to work.

Lance Osborne: So you can't go out in three days and if you don't see anything, just think that it didn't work.

Lance Osborne: And that happens with a number of some of the newer ones. They're a little bit slower acting.

Lance Osborne: So you have to be somewhat patient. You have to learn from experience.

Lance Osborne: So keep notes, if not for you, for the next guy that may be trying to control mites in your greenhouse.

Lance Osborne: We get into some controversy in trying to tell people what to do next.

Lance Osborne: In some cases, we have people that say you need to hit the mites with a different chemistry every time you apply it.

Lance Osborne: Some say you need to apply it a couple times in a row before you change to the next chemistry.

Lance Osborne: I personally believe that it's like a gun. You've only got six bullets.

Lance Osborne: If you treat it with Avid and then you switch, well, that Avid is probably still on the plant active.

Lance Osborne: You come back too quick within three to five days and it's still active.

Lance Osborne: You just covered it over with some more of the same stuff.

Lance Osborne: And you have to consider what the residual activity is and how long something may last.

Lance Osborne: So I generally say to rotate the class of chemistry four or five days.

Lance Osborne: If it's really bad, I'd try to hit it with the second application of something within about five days and then two or three times and use at least three or four different modes of action.

Lance Osborne: I don't recommend having more than four modes of action because then what happens is we've had some of our best growers put like five, six in a rotation.

Lance Osborne: And one of those six is not going to be very active.

Lance Osborne: OK, the chances are that the bug is resistant to it or tolerant.

Lance Osborne: And so you don't break the life cycle.

Lance Osborne: So if you have a dud in there, then you're not going to rotate and treat with the most effective materials.

Lance Osborne: But you have to pay attention after each application.

Lance Osborne: Does that make sense?

Ping Yu: Yes. You mentioned that we have to go back to the life cycle again.

Ping Yu: When we apply for whatever treatment that we are trying, we probably also need to think about the life cycle of the pest itself.

Ping Yu: When would the spider mite be the most vulnerable and that will make the application of the chemistry most effective, right?

Lance Osborne: Well, I think that the egg is probably the least susceptible.

Lance Osborne: Then the larval stage being small, it's really not feeding that much.

Lance Osborne: Even water and soap is going to knock it off.

Lance Osborne: But as far as chemistry goes, I think the nymphal stages are probably very susceptible, the adult being the least susceptible.

Ping Yu: So we would be, if we're applying for the chemistry or the products, the miticides, that would be the nymphal stage would be the one that we're going to target for, right?

Lance Osborne: Yeah, I would say that.

Lance Osborne: But your chemistry is going to last almost as long as the whole life cycle.

Lance Osborne: So all those stages are going to be exposed.

Lance Osborne: I'm not that worried. Some people will use an ovicide, but again, those eggs are going to hatch almost before the residual of that chemistry is no longer effective.

Lance Osborne: Yeah.

Lance Osborne: Now, if you're using something like the citric acid or things that have absolutely no residual activity, then you probably want to get the younger ones.

Ping Yu: What about the, because I know neem oil, well, like the neem oil products also...

Ping Yu: are often used to control the pests in general.

Ping Yu: If we were putting the neem oil, when would that be the best time?

Lance Osborne: I'm afraid to answer that truthfully because I've never been that excited about the neem oil.

Lance Osborne: All right.

Lance Osborne: Especially on mites.

Lance Osborne: So, I mean, I'm biased.

Lance Osborne: Yeah.

Ping Yu: Because it's not that effective in terms of control?

Lance Osborne: Again.

Ping Yu: Okay.

Ping Yu: But what about the biocontrol?

Ping Yu: Because you have worked a lot on the biocontrol perspective.

Ping Yu: What are—I know there are good biocontrol agents that are effective for spider mites.

Ping Yu: Can you tell us a little bit more of the biocontrol for the spider mites?

Ping Yu: Sure.

Lance Osborne: I obviously am a big fan of biocontrol.

Lance Osborne: I've been working on biocontrol of spider mites from the day I started here in Florida.

Lance Osborne: My predecessor, Dr. Hamlen, had worked on spider mites using persimilis and then one called macropilis, which is similar to persimilis, but it's indigenous to Florida.

Lance Osborne: We have a whole array of natural enemies that are effective.

Lance Osborne: They all have a place that can be carved out for their use.

Lance Osborne: I personally prefer using californicus.

Lance Osborne: You really want to start a population and start releasing natural enemies even before you find the spider mites.

Lance Osborne: You want them in the system.

Lance Osborne: Let them be your scouts.

Lance Osborne: Let them run around and look for...

Lance Osborne: spider mites. If you find a spider mite infestation that's pretty heavy, then you probably want to use a combination, use persimilis and californicus, because persimilis is able to knock the population down quicker than californicus. They are more voracious, but they only feed on spider mites.

Lance Osborne: So if you have a plant like ivy or a croton that gets broad mites, you're going to lose your crop to the broad mites because nothing there is to—you're not spraying and you've got a predator persimilis that won't eat them.

Lance Osborne: Okay, so californicus is critical.

Lance Osborne: Californicus will run around and it can survive on one egg a day.

Lance Osborne: Okay, so then you have this population of californicus that will almost establish in the crop, feeding on other things other than spider mites.

Lance Osborne: Persimilis is a very host-specific predatory mite.

Lance Osborne: It feeds on...

Lance Osborne: Not all spider mites, even.

Lance Osborne: It prefers two-spotted and maybe a little bit more.

Lance Osborne: It might feed on Glover mite.

Lance Osborne: It's very sensitive to the host that it has to feed on, whereas californicus isn't.

Lance Osborne: Then you have an array of other players.

Lance Osborne: We're using banker plants now, and we're using both the predatory mites and the—Feltiella acarisuga or something like that.

Lance Osborne: Feltiella, it's a little fly.

Lance Osborne: And we found that this fly can, if we put a plant in today, put a few mites on it, and have the banker plant system in all the way across the greenhouse, by the end of the weekend, three days later, we can find the midges on that plant across the greenhouse.

Lance Osborne: So they're very adept at moving around and finding spider mites.

Lance Osborne: If I take a plant with spider mites on it and put it outside, within two weeks, I'm going to have a population in Florida, at least, or Apopka, I'm going to have a population of that midge.

Lance Osborne: So they're very effective searchers.

Lance Osborne: They can be used with all the other predatory mites.

Lance Osborne: So the combination is you have something going around the whole greenhouse looking for mites, and then you have those predatory mites that are...

Lance Osborne: pretty much staying in and around where they are.

Lance Osborne: They don't travel nearly as much, and they can't fly.

Ping Yu: So I'm not an entomologist, so this might be a dumb question, but I know some of those predatory mites— like you said, they can be host-specific and some will be eating other pests.

Ping Yu: So when you decide, when you are planning or developing the biocontrol program, how are you going to decide which biocontrol agent they are going to be using, even if it's just a single agent or use a combination, how would you help people to decide that?

Lance Osborne: Okay, the first thing is you look at your crop. What kind of other pests is it going to get?

Lance Osborne: Okay, now I recommend that if you've got something that gets an array of pests and it does get broad mite, that you look at—you're going to— I just say, the swirskii. If you're going to use persimilis, you're going to have to put something in with persimilis to eat the broad mites.

Lance Osborne: So you could use swirskii, or you could throw in californicus, or you could throw in limonicus, all of which will feed on broad mites.

Lance Osborne: If it isn't too bad of an infestation, or it's really early, or from past history, that you get spider mites, then I would put in californicus as the one that I'd put out first.

Lance Osborne: But it depends.

Lance Osborne: Like I said, we try to get it started before we ever find a spider mite and let the predatory mites find them for us.

Lance Osborne: Okay.

Lance Osborne: If that crop has been exposed at all to pesticides...

Lance Osborne: like a bifenthrin or anything like that, persimilis probably wouldn't be the choice.

Lance Osborne: Californicus has some already built in, some of the—chemicals that are—

Lance Osborne: Start again.

Lance Osborne: Some of the mite populations or californicus populations that are sold have some ability to detoxify or live on plants that have been treated.

Lance Osborne: We have a strain that's been selected that's extremely resistant to bifenthrin or Talstar, so we don't have to worry about pyrethroids.

Lance Osborne: But persimilis, you open a bottle across the room and they almost die.

Ping Yu: Yeah, so I don't know how many growers out there only solely use biocontrol because normally it's going to be a combination of biocontrol, cultural control or cultural practice and chemical control.

Ping Yu: Would you, like in your opinion, what is the ratio?

Ping Yu: Spider mites would be the most effective, for instance, 80% of biocontrol.

Ping Yu: or 20% of chemical control because they're, like you said, they have, the biocontrol has compatibility with the chemical here and there.

Lance Osborne: There's certain chemicals that we can use in conjunction with biocontrol.

Lance Osborne: I recommend until you've got a trained customer, to know what biocontrol is, that you look toward the very end of the crop to use the pesticides to clean up and make sure that there's nothing running around on there to cause your customer, until they become more sophisticated in understanding what's going on and realize that it's positive to have natural enemies running around.

Lance Osborne: I think that the companies that are selling natural enemies today have a workforce that are out in the field helping growers get these things established.

Lance Osborne: I don't want to take anything away from them because they do a good job.

Lance Osborne: And so you have to work with those people because they know...

Lance Osborne: the population or the selection of particular predators that they have and what it can tolerate and what it can't. Okay. So they know that their predators have been surviving in crops that have been treated with this and this, but not this and this. So there you always go to the source and ask them okay, what they would recommend. Initially, you're going to need an extension agent or one of the chemical reps or one of those university people or other growers to help you get it started.

Lance Osborne: And that's another reason why we like banker plants because some people go into a biocontrol program thinking that's the cure-all end-all. Years and years ago at Disney we were using persimilis on roses and it worked so well they wanted to do biocontrol on everything throughout the whole Walt Disney World. That wasn't going to happen because there's too many other pests in Florida that they would—they never let me even— if I was paying, back into the park.

Lance Osborne: Yeah.

Ping Yu: So I guess it really depends. The reason why I'm asking this is because I have heard more and more people, growers, who are interested in adopting the biocontrol in their property, in their operation, because one, chemicals can

Ping Yu: be really expensive if you calculate the mass, like how many applications that they have to do.

Ping Yu: And with biocontrol, I think what the lack of training right now or even resources are the big hurdle for a lot of growers who want to get involved in there.

Ping Yu: There's—

Lance Osborne: They're increasing.

Lance Osborne: Okay.

Lance Osborne: It's like there's a new consultant in Florida every week.

Lance Osborne: Okay.

Lance Osborne: I get all these new people coming in.

Lance Osborne: So there's a lot of people that are learning how.

Lance Osborne: There's lots of videos on—

Lance Osborne: I have one, I think, a hemp website about using biocontrol.

Lance Osborne: But there are people where you can get help.

Lance Osborne: You don't want to start in a large greenhouse trying biocontrol.

Lance Osborne: Take a couple plants.

Lance Osborne: Take a bean plant, put it out in the nursery where you have some spider mite problems.

Lance Osborne: Take that bean plant and put it back, maybe even in the office or in a protected area.

Lance Osborne: Get some predators, put it on, and see what happens.

Lance Osborne: Start small, teach yourself what's going to happen so you're not totally unaware. You

Ping Yu: know what these things can do. Yeah, and there's no cure-all type of thing because it's very complicated ways, the pest itself and the crop itself. So you always want to learn, like take baby steps, like you said, start small.

Lance Osborne: I know that we had a problem in one nursery and we used one that's particularly soft, is Sultan. It could be used with the predators and it was very effective and we still had predators alive. So there are those tools. And like I said, californicus is much more tolerant than persimilis.

Ping Yu: But another perspective of pest control, where spider mite control would be coming back to the cultural control, where it's more like a prevention step. What are the cultural practices that growers can adopt to prevent the pest?

Lance Osborne: Well, I mean, first of all, when you buy in plant material, you have to realize that you might have a pest of some sort.

Lance Osborne: Yeah.

Lance Osborne: So, one, you have a quarantine facility, okay?

Lance Osborne: You have some place to watch those plants.

Lance Osborne: And so they may not have yellow stippling today, but they could have it tomorrow.

Lance Osborne: So you don't put it in and spread it throughout your whole nursery.

Lance Osborne: Two. You don't even have to have some roots on them, but the small plants, we do dip.

Lance Osborne: We've heard a lot of talk about some people doing research on dipping.

Lance Osborne: We did that years and years and years ago and found that we didn't have an increase in disease. We had very good control of mealybugs and spider mites and aphids.

Lance Osborne: Our local growers here were using, they go to a large grocery store that we have here, Publix, and buy Publix brand dish soap and make a 1% solution.

Lance Osborne: They all tried it and had good success.

Lance Osborne: That was another step to try to start with clean plant material.

Lance Osborne: You try to maximize— Mites really like or do well along in the plants that are close to a road.

Lance Osborne: Because as they're driving up and down a dirt road, you get dust on them and that gets in the webbing and actually helps protect them.

Lance Osborne: And so you end up having mite outbreaks in those kind of dusty areas.

Lance Osborne: So you need to pay attention to that.

Lance Osborne: Sometimes water will help.

Lance Osborne: People have used high-pressure water, and not too high, but can wash them and dislodge them.

Lance Osborne: Try to minimize pet plants.

Lance Osborne: A lot of times in the greenhouse, you'll get somebody that just loves tomatoes or something and they'll bring in a plant and that never gets treated.

Lance Osborne: A lot of times it'll sit there and the pest populations will build up on it.

Lance Osborne: Your sprayer guy may not go in on the aisle and treat the weeds.

Lance Osborne: And so you have to make sure that you either pull them or treat them because you can get pest populations developed there.

Lance Osborne: My wife was a professional scout for 30 years at Englemans, and she would walk in and she would just eyeball the nursery.

Lance Osborne: And you could tell places where you're going to have some issues, whether the screening is torn, whether there's pet plants and those types of things.

Lance Osborne: So you just have to pay attention to all the things that could impact your pest population.

Ping Yu: So if, for instance, if, because I know for some other pests, if they have the early infestation, early on you can do like pruning or anything like that to reduce that, especially for woody ornamentals.

Ping Yu: But if, for instance, for hibiscus, would pruning work for the spider mites?

Ping Yu: At all?

Lance Osborne: They prefer the new growth.

Lance Osborne: And so if you're cutting out all the new growth, that's going to knock the population down.

Lance Osborne: If you make the canopy more open, it's coverage.

Lance Osborne: If you don't get the chemical to the mites, you're not going to kill them.

Lance Osborne: We have a lot of materials that are translaminar in their activity, which goes through the leaf and gets the populations on the bottom.

Lance Osborne: We have some like Kontos that is a systemic.

Lance Osborne: But really, you don't want to count on that.

Lance Osborne: You have to make sure that you get good coverage, high-volume spray.

Ping Yu: Yeah.

Ping Yu: And you mentioned that they are going to be staying on the bottom of the leaf.

Ping Yu: That would be if, ideally, they can spray the chemical from the bottom of the plant, right?

Ping Yu: Or the leaf.

Lance Osborne: Yeah, I mean, that's why we have some people that are very, very good.

Lance Osborne: They end up building their own nozzles.

Lance Osborne: And they have some that are spraying up and some are spraying down so they get good coverage.

Lance Osborne: Yeah.

Ping Yu: Yeah, because that would be if you can treat, because a lot of times if it's just a regular nozzle application and just from like the air spraying, then that would be only covering the canopy that's upside in there.

Lance Osborne: You want to make sure that the pressure isn't too high, but you've got to have the pressure high enough to ruffle the leaves and get them to twist and turn so that you do get some of that.

Lance Osborne: Yeah.

Lance Osborne: And we used to have, I haven't seen anybody using it in a while, but the indicator cards that you could stick underneath the leaf that would be sensitive to the sprays and it would turn blue.

Lance Osborne: And you'd be able to tell.

Lance Osborne: And growers learned real quick that they thought they were doing a great job, but they weren't.

Ping Yu: So you kind of mentioned the indicator card and that made me think about the sticky pad or sticky card, which is pretty common to monitor the population of the pests.

Ping Yu: But are there any—like for people who are going to monitor the population of the sticky—or of the spider mites?

Ping Yu: Do you suggest them to put the sticky card in there?

Ping Yu: Do they have preference in terms of which color of the sticky card that they prefer?

Lance Osborne: They're not going to do you any good, sticky cards.

Lance Osborne: You'll catch more scouts than you will spider mites on them.

Lance Osborne: I wouldn't waste my time.

Lance Osborne: Now, some people will use indicator plants, like I said, putting a bean out in a crop.

Lance Osborne: Something like a bean is just really, really sensitive.

Lance Osborne: It shows damage quicker.

Lance Osborne: Mites love beans.

Lance Osborne: We go to Publix and buy a bag of beans, and it works great.

Ping Yu: Beans would be a better indicator than sticky pad.

Lance Osborne: Yeah.

Ping Yu: Yeah.

Ping Yu: Because I know you have been in Florida or University of Florida for over 40 years.

Ping Yu: What, now, if you get a young grower or a new grower and ask you to say how to set themselves up for long-term success, what advice would you give to them and why?

Lance Osborne: I'd say they need to be a pain in the ass.

Lance Osborne: People are here.

Lance Osborne: We're here to help.

Lance Osborne: We get paid to help.

Lance Osborne: We have a clinic that's open every Tuesday.

Lance Osborne: We don't have enough of them coming in.

Lance Osborne: And we see younger and younger kids bringing the plants in, which is very encouraging, which shows that they're excited, they're interested in new knowledge.

Lance Osborne: And I think that's number one, is to be excited.

Lance Osborne: Seek out the people that can help you.

Lance Osborne: Get a relationship with them. Have them understand what you're trying to achieve and that you're excited, you're interested in helping them and cooperating with them. And I think that'll go a long way. We have trained individuals sitting down at our clinic and sometimes nobody ever shows up.

Ping Yu: Yeah.

Lance Osborne: If nothing else.

Ping Yu: Well, you don't need anybody to wake you up.

Ping Yu: You just wake up every morning and then come to work.

Ping Yu: What about the junior faculty and researchers?

Ping Yu: What suggestions would you give to set themselves for a successful career like you did?

Lance Osborne: Well, I think number one is you just have to be inquisitive and curious and open your eyes.

Lance Osborne: Take time to look at what's going on around you and look at the plants and just enjoy yourself.

Lance Osborne: It's getting harder, I can tell you.

Lance Osborne: All the stuff we have to do nowadays, 50% of our job is just stuff to drive us nuts.

Ping Yu: Paperwork.

Ping Yu: Yeah. And I guess for junior faculty, well, I am a junior faculty myself, and I think one of the pressure or stress is getting tenure or getting your package built up. I guess for me...

Ping Yu: Paperwork.

Ping Yu: I am looking for people who I can work together with. For entomology, it might be a little bit better, but in general for ornamental, the grant opportunities are very limited. And that's one of the challenges for a lot of junior faculty trying to build a successful career in ornamental in general.

Lance Osborne: That brings me back to something I forgot earlier.

Lance Osborne: With the young people and with young faculty is that you have to become part of the industry.

Lance Osborne: What helped me is I used to go to a donut store every morning and I ran into a grower there.

Lance Osborne: The Delphastus is sold all over the world now.

Lance Osborne: It came from his backyard.

Lance Osborne: The fungus that we patented, the PFR-97, Ancora, that came from some plants in his greenhouse.

Lance Osborne: So the industry and really support...

Lance Osborne: the grower organizations, okay, like HRI, FNGLA, become part.

Lance Osborne: And if you want to have a long career, then these people are going to be the people you see from now on for the next 40 years.

Lance Osborne: So you might as well make friends with them.

Lance Osborne: Let them know what kind of person you are.

Lance Osborne: Okay, I went to a nursery where the guy, he knew the answers to all the questions, but he wanted to see if I knew them.

Lance Osborne: And you don't BS people in this industry because if they're still in business, they're probably smarter than I am.

Lance Osborne: And—

Ping Yu: No, I totally get it.

Ping Yu: Especially for me, I think right now, a lot of people out there are more knowledgeable than I am.

Ping Yu: A lot of times it makes me nervous to answer a question because I'm like, I don't know if I'm saying it right.

Lance Osborne: I agree.

Lance Osborne: You just...

Lance Osborne: find mentors, people that you can...

Lance Osborne: If people can trust you, they're going to look to you to support them, to work with them.

Lance Osborne: We can't do this ourselves.

Lance Osborne: It's just too much going on.

Lance Osborne: I'm setting up field trials right now.

Lance Osborne: I'm trying to find people that want to try some banker plant stuff.

Lance Osborne: And some, they just want to sit in their own little world.

Ping Yu: Yeah, yeah, yeah.

Lance Osborne: You don't have...

Lance Osborne: Money is not the answer.

Lance Osborne: You can't throw money at stuff, but it does come easier when people see that they can cooperate with you.

Ping Yu: But what—I know you are a person who gets excited with everything, even after you've been working for 40 years.

Ping Yu: But what is your next excitement for your work, for research, or for your life in general?

Lance Osborne: I know this is going to sound weird, but I'm getting excited about mealybug biocontrol.

Lance Osborne: There's a reason why if I go out, I can't find mealybugs.

Lance Osborne: I'd be up to my eyeballs in mealybugs if there wasn't biocontrol out there somewhere.

Lance Osborne: Something's eating them all.

Lance Osborne: Okay, so we're finding, taking plants out, sticking them in the bushes, coming back in a week or so, and if somebody hasn't stole it, we end up with the plant that generally has mealybugs and natural enemies on it.

Lance Osborne: So we're trying to colonize them.

Lance Osborne: We've got a little tiny fly that's going nuts on mealybugs that we didn't even know was there.

Lance Osborne: I've got a little tiny ladybug that eats mealybugs.

Lance Osborne: I'm having a hard time growing mealybugs.

Lance Osborne: And...

Ping Yu: Because there are natural enemies somewhere in the greenhouse?

Lance Osborne: Yeah.

Ping Yu: And you didn't even know what it is?

Lance Osborne: I didn't know that.

Lance Osborne: Well, I can't get identifications on some of them.

Lance Osborne: The little fly I dropped off at Gainesville a week or so ago to see if somebody could identify it.

Lance Osborne: We have a parasitoid for a Madeira mealybug that we sent out, and we still haven't gotten an answer on.

Lance Osborne: I mean, some of these things are new.

Lance Osborne: And it just took throwing a plant in the bushes and then bring it back into the lab.

Ping Yu: Wow, that's interesting because, I mean, you would think that...

Ping Yu: The whole thing with mealybugs sounds interesting to me because you would think that they're going to stick in there and all of a sudden they're gone because of other existing pests or parasites in there.

Ping Yu: Yeah.

Ping Yu: Yeah.

Ping Yu: Are you still in the phase of sorting out the mealybug and what causes the issue or what are the natural enemies of the mealybugs?

Lance Osborne: Well, the enemies we're finding are in a number of different categories.

Lance Osborne: We have predators, we have the fly, and a caterpillar, which is eating them.

Lance Osborne: But unfortunately, they're feeding a little bit on the plants, so we're ruling that one out.

Lance Osborne: We've got ladybugs.

Lance Osborne: Some predatory mites, but I think the ones that are showing the most interest are a parasitoid, the ladybug, and the little fly. We have colonies of all three of them. Wow. And so we're off to the races.

Ping Yu: Yeah, more interesting work is going to be out for mealybugs.

Ping Yu: And hopefully we'll get another episode on mealybugs down the road.

Lance Osborne: My hope is to find a commercial company that's willing to rear them.

Lance Osborne: We do have a banker plant system for the mealybugs.

Lance Osborne: But growers don't want to do that. They want to be able to purchase something and release them.

Ping Yu: Yeah, yeah. So with that in mind, if people want to find more of the information with all the work that you have done, where do you recommend them to go and find more information?

Ping Yu: Okay, so we'll just email you and call you in to find more information.

Lance Osborne: Yeah, I can send them some PowerPoints and PDF files of talks I've given.

Lance Osborne: But I need to know the specifics and I can work with them from there.

Ping Yu: Yeah, okay. Sounds good. Well, thank you, Lance, for joining me today.

Lance Osborne: My pleasure.

Ping Yu: I have learned a lot with this, but thank you for still being so excited to provide your knowledge to our industry. I think it's really something we need for. And that's why I was like, you are kind of one of the icons in the industry, because you are providing all those services, your knowledge, your skill to the industry so that

Lance Osborne: we as a whole can survive together. So thank you. Thank you.

Ping Yu: Besides the resources and information that our guest speaker shared with us today, AFE also has additional resources for mites and other insect pests that can be found on AFE's website at endowment.org.

Ping Yu: I'll put those in the show notes as well.

Ping Yu: This episode in our first season is made possible through an educational grant from the American Floral Endowment, where research priorities helped shape the topics that are featured.

Ping Yu: To learn more about AFE and access their research and educational resources, visit their website at endowment.org.

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Ping Yu: And as always, go check out the show notes to learn more about this topic and other things.

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Ping Yu: Till the next time, stay healthy and go plants.