The Battle Against Forest Pests Adam Baker on Invasive Species and Tree Health

Episode Overview

Episode Topic

In this episode of Timber Talks, host Mindy dives deep into the pressing issue of invasive species affecting our forests, featuring guest Adam Baker, a research entomologist at the Davey Tree Expert Company. As National Tree Check Month emphasizes the importance of monitoring forest health, Adam discusses the growing threat of pests and diseases to our ecosystems, highlighting the critical role they play in changing the landscape. The conversation covers the distinction between invasive and non-native species, explaining how these invaders, unchecked by natural predators, disrupt forest ecology and outcompete native species, impacting soil chemistry, light regimes, and overall forest health.

Lessons You’ll Learn

In this insightful episode, listeners will learn the vital differences between non-native and invasive species and why the latter poses a severe risk to forest ecosystems. Adam Baker sheds light on the ecological impacts of invasive pests and diseases, explaining how they alter forest composition, soil chemistry, and light availability, ultimately threatening native species and biodiversity. You’ll also learn about the economic toll invasive species take, from costly management efforts to the loss of valuable forest resources.

Adam discusses the latest advancements in detecting and managing invasive species, including the use of AI technology and drones for precision-targeted treatments. Listeners will explore practical tips on how communities and individuals can contribute to controlling these species, emphasizing the importance of being engaged with local landscapes and leveraging modern technology for better forest management. This episode is a must-listen for anyone interested in forestry, arboriculture, and environmental conservation.

About Our Guest

Adam Baker is a research entomologist at the Davey Tree Expert Company with a deep passion for forest health and tree care. With extensive experience studying the impact of invasive species on ecosystems, Adam has contributed valuable insights into how these pests and diseases disrupt the balance of our natural landscapes. His expertise spans from studying insect-plant relationships to developing innovative solutions for managing invasive threats in forests.

Adam’s current work focuses on using advanced technologies, including artificial intelligence and drones, to enhance the detection and management of invasive species. His research aims to find sustainable and effective methods to protect our forests from the growing threat of these ecological invaders. With a background in entomology and a commitment to preserving biodiversity, Adam Baker offers a wealth of knowledge that is both informative and essential for understanding today’s challenges in forestry and arboriculture.

Topics Covered

This episode covers a wide range of topics centered around invasive species and their impact on forests. Key discussions include the definitions and differences between non-native and invasive species, highlighting examples such as the emerald ash borer, hemlock wooly adelgid, spongy moth, and Japanese beetles. Adam Baker explains how these species spread, the ecological damage they cause, and the economic implications of managing their outbreaks in forested areas.

Listeners will also hear about the latest technological advancements in the fight against invasive species, such as the development of AI tools and drones for targeted treatments. The conversation explores practical strategies for early detection and rapid response to invasive, emphasizing community involvement during National Tree Check Month and beyond. Additional topics include the benefits of forest conservation, promoting biodiversity, and understanding the broader environmental impacts of invasive species.

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About the Guest: Adam Baker

Episode Transcript

Mindy : Welcome to another episode of Timber Talks, the podcast that dives into the world of forestry and arboriculture. I’m your host, Mindy, and today we have a very special guest with us, Adam Baker, research entomologist at the Davey Tree Expert Company. Adam brings a wealth of knowledge and experience in tree care and forest health, and we’re excited to have him here to discuss a critical topic pest and diseases in our forest, especially during National Tree Check Month. Welcome to the show, Adam.

Adam Baker: Thank you very much for having me today. Appreciate that. Always talking trees.

Mindy : So trees are so important. People just don’t realize. So you explain what defines an invasive species and the kind of threat they pose to our ecosystems?

Adam Baker: Sure. I mean, I think it’s important for us to explain the difference between invasive and non-native. Whereas non-native is just something that’s not native to the region but isn’t going to be causing any sort of ecological devastation, whereas an invasive species has the capacity to change the local ecology. So some examples of that would be when an invasive species comes in, it’s generally released from its natural enemy complex, which are the pathogens and predators and parasites that generally take advantage of that species, which enables them to reproduce at a much higher rate than what they normally would in their native ranges. So they come in unchecked by the natural checks and balances of the forest, and then they’re able to spread rapidly. And oftentimes they’re like places where disturbance is happening. So you generally you’ll see these infestations starting at trail edges or places where construction has happened and then, lo and behold, you have a tree or something fall in the canopy of the forest. They can encroach in those areas where that sunlight is taken up. So, yeah, those invasive species are things that come in unchecked. And then for through their invasion status, they can cause lots of impacts on the ecology. They can, for instance, displace native species that are filling the same competitive niche as the invasive species. They can change the composition of the forest, which then is going to have impacts on the chemistry of the soil and the light regimes that are coming through the canopy, as well as influencing that surface level temperature.

Mindy : Could you give us some examples? I know that emerald ash borer is invasive. What are some other invasive species that people may be familiar with?

Adam Baker: Sure.

Adam Baker: I’m going to be, you know, focusing on being as an entomologist. I’m a bug guy. I’ll focus more on those. But uh.

Adam Baker: You.

Adam Baker: Know, certainly emerald ash borer is a big one, which is a jewel beetle species that, you know, same sort of thing. It comes in unchecked, all of our native ash trees that did not evolve with this species, often with insects and plants. There’s this dynamic between they call it the insect plant relationships, where this is usually this ecological arm race that happens where a plant creates a defense and insect. It figures out how to overcome that defense. But when you have an insect that does not evolve with that plant species, the plant really has no natural resistance to those other ones out there that are causing problems. Of course, the hemlock wooly adelgid, uh, which affects hemlock trees. It’s one of the first projects that I actually worked on as an undergrad in Wayne Gretzky, Katie’s forest entomology lab, where we’re looking at how changes in hemlock dominated stream canopies versus deciduous stream canopies would influence the guilds of insects that were present in those streams. Which it certainly does. Other examples are things like spongy moths, which can defoliate thousands and hundreds of thousands of acres when they go in there. Outbreak.

Adam Baker: Outbreak. Status. Things like spotted lanternfly are one of the newer ones on the horizon. They’re just now being found in Michigan and Ohio. The areas that I’m at, they’ve been well established in Pennsylvania for a few years now, as well as, you know, the Mid-Atlantic. Things like Japanese beetles are also out there, as well as Asian longhorned beetles. That’s another one that has the potential to cause a lot of impact. But then there’s also the plant side too. So we have insects that generally come in and they’re able to attack plants that are unable to defend against them. But then there’s also the plants that come in and sort of change the structure of the canopies and change the composition of the forest. So things on that list should be like bush honeysuckle. Autumn olive Japanese knotweed was running rampant in our area right now. But then you also have like perennials and grasses as well. Things like cutleaf, teasel and stilt grasses that come in reminds like Japanese vining honeysuckle that can also come in and sort of smother out and pretty much just lower the diversity of those areas.

Mindy : Right. Katsu’s a big problem where I’m at. I mean, it takes over the mountain. And so the about the only and it’s just a band aid. They just do aerial spray, you know, but it doesn’t kill it permanently. It just dies down the vegetation and then it comes back up. But I did see goats like it a lot. And ironically, it makes good moonshine, supposedly. So you know that that would be a unique product for kudzu, a way of controlling it.

Adam Baker: Yeah, I agree. Uh and my graduate school in Kentucky. So I’m pretty familiar with that one. And it’s got the flower. It smells like that fake grape flavor, like grape Kool-Aid.

Adam Baker: Right?

Mindy : Right. Well, where I was raised, I mean, it’s it’s been in the area, I’m going to say probably five years. And it just grows over everything. And um, like I said, they just spray it about three times a year and they cut it to keep it because it grows, it covers the road. So they cut it to, um, to control it. That way they haven’t found anything to just completely eliminate it. Unfortunately, according to the US Forest Service, 26 different insects and diseases are putting 70 million acres at serious risk. Could you provide some examples of these invasives and their efforts?

Adam Baker: We’ve mentioned this.

Mindy : Let me backtrack. I thought that said effort. It says effects. I’m Sorry. According to the US Forest Service, 26 different insects and diseases are putting 70 million acres at serious risk. Could you provide some examples of these invasives and their effects?

Adam Baker: Sure. So like we mentioned before, you know, the wooly adelgid, the emerald ash borer moth, things like that are non-native, invasive insects that can come in and cause big devastation. But on the other hand, there’s also a lot of native pathogens and insects that can go into outbreak status. So, you know, for instance, some of the pine beetles, as the stands of trees get more stressed, as we’re experiencing different in our precipitation and as well as our temperature. These trees are sort of in a state where they’re vulnerable, which can lead to outbreaks of native pests as well. You know, we also see this in diseases with some of the the wilt diseases and some of the cankers, as well as things like fire, blight, um, that are that can run rampant through areas, um, when trees get stressed, you know, that’s another thing we’re talking about natives and invasives a lot. And it’s, uh, there’s a great talk from a professor at Cornell that I saw that the topic was native to when native to where. And oftentimes we use the word native as native to North America. But sometimes they’re not going to be native to your state or your county. And oftentimes, you know, we sort of assume that these native status is static, right? Whereas the environment is not static. It’s changing. And as that happens, you know, different species will move in and out and then move with those to, uh, to align themselves with the condition that’s going to be suitable for their growth.

Mindy : Right. Well, I saw a thing, um, a few years ago. They were from National Geographic, the walking trees where trees are going up higher and species that weren’t in higher elevations. They’re finding them now. Higher up due to environmental changes. So yeah the the hardiness zone is changing due to many factors unfortunately.

Adam Baker: So yeah that’s a big concern. And so I did all of my PhD work in monarch butterfly conservation. And as you know, the monarchs overwinter. And these oatmeal fir forests and the highlands of central Mexico. And you can imagine if if those trees get displaced because of this sort of thing, you know, what’s going to happen to those overwintering grounds or those specific trees important to the overwintering signaling for monarchs, it’s sort of unknown, but it’s an example of how, you know, those sort of shifts in canopy composition can maybe influence, you know, things like the monarch migration.

Mindy : Right? The cascade effect, unfortunately, you know, when one falls, they all fall, so to speak, what kind of economic impact to invasive species. Have I read that the US spends billions annually on this issue?

Adam Baker: Yeah, certainly. And to your point about the kudzu, right? One reason why kudzu is so rampant is because it’s such a hard area to get to. It’s a species that climbs over, literally climbs over other species to get to the canopy light and takes it over. And often you’re in very steep areas that are hard to get to. We saw this as well when a hemlock wooly adelgid came through. You know, uh, insecticidal soaps and oils and stuff work pretty well against them. But as you can imagine, it’s pretty hard to go into a dense forest and spray do a spray on a hemlock tree. It’s 120 ft tall. So, uh, the difficulty is, is finding treatments and management that’s going to be effective and is also going to be realistic for practitioners to be able to get that up there. And actually perform. So oftentimes you’re leading towards things like, uh, injections of trees that can be very specific to the tree. It’s going to have a low impact on the rest of everything else around it. Um, but it also limits the, the management strategies that we can that we can, you know, employ in those, um, things like the, uh, Asian longhorn beetle, you know, they’re doing removal of trees, um, that are infested with alb, um, to try to eradicate populations because they can attack about 12 species, uh, of hardwoods. And, uh, as you can imagine, you know, tree removal isn’t cheap, especially if you’re doing it in a place like a forest that’s hard to get to, hard to access. Um, and that’s just talking about from the forest standpoint. You know, we also see a lot of this leaking over into agriculture, especially with Japanese beetles and spotted lanternfly. That’s another huge economic input. And the residential properties as well, that have to deal with these invasives, and often these areas can harbor invasives that they can then start working their way out into the forest. So it’s important that we knock them down before they get into those hard to reach areas, or else that management expense just get higher and higher.

Mindy : Right. Well, I had a previous guest and he was a futurist, and he was talking about how we have the technology now, but drones that could be flown with that would hold occupants where scientists or firefighters or rescuers, it would be easier to get to these remote areas to study the problem, treat the problem, whatever the situation called for. Do you see something like that as far as a possible treatment for this invasive species? You know, because, you know, kudzu in my world is just everywhere. And really all they’re doing is just spraying from a helicopter and taking out, you know, whatever the spray hits, it’s going to be taken out. So do you see technology maybe playing a role in the control of invasive species?

Adam Baker: Yeah, we’re actually currently working on these questions right now here at Davie, where we’re working with, uh, software companies and internally to develop AI software that can recognize different invasive species. So you can imagine with your helicopter example, you’re going over and you’re flying over and you’re doing a broad spectrum spray that’s hitting everything, right. It’s really expensive to hire a helicopter. It’s really expensive to fly a helicopter. Whereas a drone, for instance, uh, sort of the area we’re looking at is like right of ways, you know, energy transmission areas, right, which are a disturbance driven area that are prone to attack by invasives. So, uh, theoretically in a few years, what we would like it to be able to do is you’ll fly over with the drone and you’ll take spectral analysis of what’s going on beneath. You’ll put, uh, geolocation points on all of the identified invasives and then a drone behind it equipped with an herbicide that can selectively spray just that single plant can come by and automatically go to all those program sites and spot spray all those areas. And that’s great for areas that are really, really hard to get to when you can’t pull a big team out there. So we are working on that kind of stuff right now. And, uh, but technology is catching up to these questions. And, uh, and I think in the near future we’re going to start seeing a lot, a lot more of that.

Mindy : Okay. I’m very, very similar to precision farming type of thing, where.

Adam Baker: That’s exactly where the technology is coming from. But much easier system to understand there where you’re dealing with out there. It’s a complex mosaic that needs to be understood. And, uh Yeah, exactly.

Mindy : Adam, could you tell us about the latest advancements in detecting and managing invasive species? So you mentioned about AI. Do you have any other new tools that are coming down the pike?

Adam Baker: Um, I mean, that’s one of the big ones that’s coming. And we’re also using it from a conservation standpoint. So one of the projects I’m working on now is using AI to identify stems of milkweed for things like Monarch car compliance, which is a program that conservation and right of ways. As far as that, I think another big one is sort of the integration of asset management technologies. So being able to have years and years of data accessible with a single click or two in your asset management software tools, which can give you an idea that what has been done, what treatments have been done, what historically has been causing a problem here. And then there’s also, you know, some some AI stuff that can Not.

Adam Baker: Help predict.

Adam Baker: When you might have more problems. So then you can sort of, you know, it’s hard to cover these hundreds and thousands of miles of these, you know, for instance, transmission right of ways with boots on the ground all the time. So having things that can help predict these areas, having those monitoring tools and having at your fingertips the ability to look at infestation history and treatment history are all going to lead to a more precise, I think, management of invasive species and help eliminate some of the costs of just going out and surveying with boots on the ground.

Mindy : Tree check month is a key initiative. What actions can communities take to contribute positively during this month and beyond?

Adam Baker: So I think, uh, you know, part of the the tree check month, you know, not only helps identify things like outbreaks of Asian longhorn beetle that that may have gone unnoticed otherwise, but one of the other big parts of it helps build a connection with nature, and it helps build a relationship with the landscape with with the humans who are being engaged, the citizen scientists that are going out and checking their trees. This is really cool. Body of literature by Robert Pyle that explains the extinction of experience, where he essentially goes out and surveys a bunch of areas and asks, you know, children in different urban or rural areas, their experiences. And if you look at, at sort of the data, this time goes further on. Humans are spending much less time outside. They’re engaging in a lot less environmental activities. So I think something like this is going to be valuable in the standpoint of it could lead to early detection of invasives, instill a love for nature and the connection to nature, which, you know, we may not, you know, have or we may need to rebuild. So it’s going to help, you know, promote awareness and promote overall human health as well as we’re thinking about maintaining those canopies and having them as integral part of our landscapes.

Mindy : All right. Well, I had a previous guest that was talking about I saw a while ago where I think it was Japan, where we buy memberships to gyms, they buy memberships to forests, and it’s just for the health benefit. It’s not for like grilling, you know, that type of thing. Because of the studies that were done with the good bacteria falling out of the trees and landing on humans to build our immune system. But this guest was telling me there are actually physicians that give prescriptions for time in the forest, which I thought was just really interesting because where I’m at, there’s a state park that was named after a man in the from the 1930s, and he was sick, and he kept going to the doctor, and the doctor said, I don’t know what to do for you. Just go out in the woods for 30 minutes a day and see if that improves. You know, your symptoms. And so he started doing that. Then he increased his time. Then he really started developing an interest in forestry and ended up being a naturalist. So I’m seeing this cycle back to nature. And seeing nature has more value than, than the cost of the land or the cost of the timber that you could get off of it, that there are some people out there that are actually trying to calculate a true value of, of a forest. So we have a better idea of what, what we’re really working with. Because where I’m at, the value of the forest is just a space to put another apartment building, and they’re just taking trees down like crazy. But I kind of my personal job, I kind of see this, this swing of change, almost like a modern day flower child type of thing coming around where people are valuing trees and hugging trees and, and that outdoor experience that a lot of people choose not to have in today’s time. What role do you go ahead? I’m sorry.

Adam Baker: Uh, I just said to go off of that, uh, you know, we do what we call forest bathing. We go out and during our class hour long training sessions and spend some time in the forest. But, yeah, there’s a whole there’s a whole body of literature out there that looks at reduction in crime rates compared to canopy closure, reduction and suicide and overall mental health. Uh, and there’s a cool project that the University of Kentucky was working on. I was leaving that was a joint effort between me and the landscape architects and the hospital, where they would take patients who were coming in for for treatments at the cancer center, and then they’d either take them out on the one side that’s filled with boxwoods and honey, locusts and hydrangeas, or they would take them out to the other side of the building where they have a diverse planting of native plants, and then they compare stress enzymes after to see how they’re coping and dealing with with the stress after, you know, post-treatment. And so yeah, I think that’s a great point. And the I think the more healthy canopies we’re going to have, the the healthier and happier we’re going to be in general.

Mindy : So why I was raised in the country. So I was raised in the mountains, and had trees everywhere. So I when I was a teacher, I taught in Louisville, Kentucky, and it was a city school. And I was just shocked. I was shocked at what the kids didn’t know. And I was shocked at, you know, just this idea of going outside because that part of Kentucky’s got a pretty high crime rate. So I can understand, but just not going to a park, or having looking at your window and seeing a tree, or it was actually quite depressing for me. So, you know, we would go outside. I had three greenhouses. We would go outside and and play in the soil and, and get some vitamin D therapy and, and stuff like that. But I just couldn’t wrap my mind around that. There were people out there like that, that were either afraid or had never been to a park or, you know, I was just not raised in that type of environment. But I was just like, culture shocked over. I never, you know, been to a park or, you know, just type of thing. It was just it was very eye opening and that was many years ago. So but yeah, that’s interesting that the University of Kentucky’s doing that or was doing that kind of research as far as cancer treatments, maybe that down the pike will be a you have your cancer treatment, and then you go out and you sit outside for a while to help with that type of treatment. What are the best approaches for dealing with invasive species, especially for early detection and rapid response?

Adam Baker: Um, well, I mean, so like we just talked about the, the tree check month, you know, being engaged with your landscape is going to be a big part of that. If you’re hands off, complete with your landscape, you’re certainly not going to notice things like new, invasive. You’re not looking up at the canopy of your tree and thinking about its health at least a couple times a year. You’re not going to notice changes as it starts to have die back or it starts to have issues. So being engaged with your landscape is going to be an important part, and also being in tune with your local extension offices. So the land grant universities that are putting out webinars that are releasing, uh, nice little one, two page handouts, uh, you know, usually they’ll have alerts on their little things to look out for. They’ll have, you know, management options and stuff like that. So being in tuned with all that sort of stuff going on in your local areas is definitely going to help you to identify and, and, and jump in for that early detection in your local area. So yeah, reach out to your local extension offices. Reach out to people like us if you need help identifying things in the field. You know, utilize things like the laboratories. They can do pest identification and stuff for you. We can take a sample. You can bring it in and they can tell you exactly what’s going on there. And that’s going to give you an idea of how to manage your property and what steps to take.

Mindy : Is there any legislation that you’re aware of that has any type of where they are marking like landscape material, if it came from China or whatever? Because I know a lot of the invasive Species have have either voluntarily or involuntarily came to a North America. And one of the big markets is landscape plants. Are you aware of any type of legislation going on?

Adam Baker: Um, so it sort of depends.

Adam Baker: On the state and the outbreak status of what’s going on. But certainly we see that, you know, we saw it with potted plants where grubs were in the soil. Potted plants for Japanese beetles in the early days of that, right now we’re seeing with box tree moth. So as you can imagine, you can walk out in any neighborhood and you’ll find a box, boxwood, and pretty much every single property. And they have just a whole slew of pathogens and insects that utilize them, most of them coming from their native range that have been established over here now. And because of just how many and how frequently and how closely spaced apart, these things can jump from property to property. So a box, tree, and moth right now in Michigan is all under quarantine from moving out of certain counties because they’ve had, you know, detected infestation. So they want to make sure that they’re not shipping off infected material into neighboring areas. You know, increasing that, the speed of that spread. So there will be times where those restrictions are put on. It’s generally, like you said, coming from a nursery stock sort of aspect and stopping the movement and making sure they go through the quarantines before they’re allowed to be moved out.

Mindy : Okay. Is for a homeowner, is it better to have a more diversified type of landscape or the traditional, you know, just 3 or 4 different plans boxwoods some annuals as far as invasive species, or does it really? It just doesn’t matter because I would tend to go with if I was going to hire a landscaper, a landscaper that used native plant material because they’re more adapted to the environment, obviously. But are you finding that having a variety of different plant material is a better approach for a person’s landscape, or, I guess, where I’m going to keep if your neighbor has invasive species, if you had diversified plantings, to me, that would be kind of a not a permanent safeguard, but a better approach versus having more I don’t want to say monoculture, but, you know, boxwoods, maybe some Colorado blues, some deciduous trees and then some annuals planted around, or does it just not matter?

Adam Baker: So part of it has to do with the context of what you’re trying to achieve. So I think about this a lot in like the ecology of our landscapes. And you know, there’s no one size fits all. Um, certainly. Um, but you know, identifying what you’re trying to achieve is, one important part. So for instance, in the context of like a right of way, there’s something called integrated vegetation management where they’re trying to implement a native canopy that will then suppress germination of invasives. So you’re going to reduce herbicide applications because you’re maintaining a healthy canopy of species that are meant to be there, that are equipped to be there in the home landscape. However, you know, for instance, if you’re your main goal is to support pollinators. One thing that you would want to do is provide flowers for as long throughout the season as you can, from early spring to late fall, because certain species of bees come out for only several weeks in the spring or the fall, some are there throughout the entire season. So having that pollinator buffet from spring to fall, then also having flowers with different flower forms, so ones with deeper nectaries are going.

Adam Baker: To.

Adam Baker: Support larger bees on the smaller nectaries are more discreet. They’re going to be supporting butterflies or small native bees. And then you want to, of course, reduce the amount of insecticides that you’re going to be using. And you want to maybe be okay with things like clover in your mixed species lawn. And in that case you want to use a majority of native species. But, you know, for instance, in Kentucky, uh, the seven suns flower is a cool tree that blooms in September. And if you go out and you see a seven suns blooming and talking in September, it’s just covered in monarch butterflies. It’s covered in late season bumble bees. Well, nothing else is really blooming at that time. So it’s a non-native that doesn’t have really invasive potential. So in that case, you can use some non-natives as either to extend seasons or to add visual interest. And then also, I think it’s important not to demonize people that want to have a little touch of something different. There’s, you know, my wife is a horticulturalist. She loves plant diversity. And that doesn’t mean everything is 100% native on our property. But, you know, her grandma had lots of peonies when she was growing up, and she loved the peonies. So she’s got a patch of peonies and I think that’s okay. Just avoid species that are going to be prone to being invasive.

Adam Baker: They’re going to be aggressive. Things that often spread rhizomes are going to be sort of prompt, prone for spreading in the environment and spreading to your neighbors properties. But then it’s your, you know, if your goal is supporting birds, you know, like with the sort of the Doug Tallamy bringing nature home sort of mindset and his sort of message is to plant trees that are going to host a lot of different larval forms of insects. So something like an oak tree is going to house hundreds of different species of moths that are going to eat the trees. Those moths, those caterpillars are going to feed the birds, and they’re going to support the birds, and they’re going to attract more birds to your property. So it’s kind of just a matter of the context of what you’re trying to achieve. But I think there’s a way to marry sort of formal historical as human esthetics with natural areas. We can still maintain the formal, the straight lines, the, but we can use native species in place of the boxwoods and the highly modified hydrangeas and the arborvitae. There’s other plants that can that can fill those roles for us and provide that same formal aesthetic, but provide habitat for our native species as well.

Mindy : Can you share some tips to how to prevent the unintentional spread of invasive species?

Adam Baker: Sure. So when you’re looking at your.

Adam Baker: Your landscape, you know, looking at it from like an insect standpoint with this example is we want to limit our use, broad spectrum insecticides that aren’t going to be addressing problems that are actually affecting the health of plants. So for instance, we can use what’s called reduced risk insecticides. And there’s a great example in the lawn where you have problems with Japanese beetles. There’s several different chemistries you can use in the lawn. One of them is a neonicotinoid that can, uh, basically is broad spectrum for all insects. It can translocate in the nectar and pollen if you’ve got things like violets or clover popping up. But there’s also something called anthranilic diamines as an example that has no activity against things like bees and ants. And, you know, ants are a huge predation pressure in the lawn that can help control things like turf feeding caterpillars and and other things that come in laying their eggs in the lawn. So, uh, you know, maintaining, using reduced risk options, treating when only treatment is necessary and depends on the health of the tree rather than esthetic value. So a good example of that is like hackberry. And they get the hackberry nipple galls, which some people find. Very unsightly, but it’s not harming the tree at all. So treating for that. Could be causing problems in your landscape. And the problems that are caused by that sort of thing is that generally, the herbivore insects are way better at metabolizing these, these secondary chemicals that are in pesticides, because a lot of these pesticides are derived from secondary plant volatile chemicals. So these insects are prone. So that basically what that means is that predators are way less resilient to insecticides than are herbivores.

Adam Baker: So if you go out with a treatment, you know, one of one great example of this is the mosquito sprays. If you go out and spray for mosquitoes, you are going to kill a small population of the herbivores that are there. But you’re going to be knocking back all the spiders and predatory beetles, and those are going to take way longer to rebound than our natural, than our natural enemy. Complex. All the predators and parasites. So you’ll often have things like secondary outbreaks, mites or aphids and things like that that happen. So just maintaining your landscape in a way that’s going to maintain the natural enemy complex, you want to feed the predators and parasites with nectar and pollen. You want to provide habitat for them where pesticides aren’t being exposed. There’s this idea of like beetle banks where you can plant flower strips that support them, and they can hide in there and then migrate out into your areas to, to feed on, on the, you know, invasives or problematic pest insects. So maintain that complex going to help to stop the spread. And then as your point before with things like plants, if you can get a you know, no planting is absolutely stabilized. But if you can get a healthy canopy cover, even in a disturbed area, it’s going to be much harder for those invasives to come in and establish. If you’re having maintain an area that has no plant cover, there’s often more room for for things to come in and start establishing.

Mindy : Right? It’s easier. So what advice would you give to someone looking to plant diverse native plants and manage their gardens to avoid invasives? And we’ve kind of touched on that. You talked about not planting something that spreads by the roots. So what are there some other suggestions that you would give?

Adam Baker: Um, yeah.

Adam Baker: So if you’re, you know, let’s say you’re moving into a new property and you just moved in, you had a legacy of of invasives that you’re dealing with. One thing you can do is start knocking them back. Um, so you’re having things pop up. You can always deadhead them, which means just cut off the seed pods. It’s going to stop, spread that way to help maintain them until you have time to get them fully removed and start replacing them with other species. Oftentimes, if you have a place that has a long history of invasives, you’re going to have a seed bed that’s actually just full of these things. So realistically, you can’t just come in and cut it down and plant what you want because you’re still going to have those problems for a while. So having the patience to.

Adam Baker: Approach.

Adam Baker: The seed bed and diminish the seed bed to a point where you can get a healthy native canopy established is going to be important. You can do that through solarization or through herbicide applications or a combination of both to to achieve that. But having that patience and not wanting that instant gratification that often leads to a failure and then a change, a change of direction. The ten 2030 rule that they use for designing urban canopies. So you want to have no more than 10% of species, no more than 20% of a genus, and then no more than 30% of the family And these are sort of they help stop the movement of insect pests. So, you know, early on with like EAB, when we have a road that’s lined on both sides with the same cultivar, Green Ash Tree for two miles straight, while that beetle just jumps from tree to tree. We saw this with elm tree. We saw this with ash trees. So not having you know, we do like that formal canopy esthetic. And another thing that I like to think about too is, is, you know, if we’re really trying to support different species is to look at sort of the, the biology and the life history of the species we’re trying to support. So for instance, things like bees, right. If your main goal is to support bees. Oftentimes bees, um, won’t go out or they’ll go out and they’ll find a flower that they find is an appropriate host. It’s got good pollen and nectar. And then instead of visiting different flowers the rest of the day, it’ll selectively forage from the same type of flower.

Adam Baker: Over and over and over, which.

Adam Baker: Is called optimal foraging theory. So one strategy that we could do, you know, oftentimes when you talk about pollinator habitat, different seeds, and we pop it out, we grow it and it grows to this Monet-esque, super complex mosaic of flowers, which is aesthetically pleasing for us. But for a bee, it’s kind of a nightmare, right? Because now it has to somehow navigate those flowers. So we could, for instance, plant in clusters where that bee could go visit a cluster of flowers, visit that same cluster over and over, which greatly minimizes the foraging effort that it takes for that bee to, you know, get the resources that it needs. So getting away from the anthropogenic gardening standpoint and then using nature as a reference for how we should maybe think about putting our plantings in, can help inform and optimize our landscape plantings as well. It may have shifted topics a little bit, but I That’s right.

Mindy : So that’s why, um, you know, I do know MoMA Mae from the bees. And because the dandelions are out then, so I it drives me crazy when I see people spraying for dandelions. But, you know, it’s just you gotta let nature do its thing is sort of my motto. But yeah, that’s very interesting planning and clusters versus more of like the formal, the formal planning. So they don’t have to hunt and peck for that particular flower that they really like.

Adam Baker: As is, you know, like monarch butterflies as well as we have a species that finds their host plant by using visual silhouettes and cues. So in this case, oftentimes monarchs usually only plant their eggs on the perimeter of milkweed plantings. Or they really prefer isolated plants because it maintains that really nice, strong silhouette that they can train to and attune to. So having things like that, that build into the idea of ecology in the landscape, for one, it’s going to optimize what you’re trying to accomplish. And for two, it also builds a story that leads to conversations in your landscape where it’s like, well, I’ve got a bag of seed and I put it out and now there’s flowers. You say, well, I thought about this and designed it this way. And now we’re optimizing our habitats using the ecology of the organisms we’re trying to preserve, which makes it just for me, more exciting. And that ecological storytelling is going to instill that, that passion for nature.

Mindy : Well, I do know, at least in my area, they have a milkweed project where people can get milkweed seed. And so I wasn’t familiar with them being visual clues, so to speak, as to where to lay their eggs. But that makes a lot of sense, because I see a lot more monarch butterflies in fields and stuff that, you know, had milkweed. But the milkweed plants are so spread out. It’s essentially one plant here, one plant there. And they seem to have more activity with the monarchs than homeowners that have planted a cluster of milkweed to either attract monarchs or to help monarchs, whatever their goal is. So that’s really that’s really interesting about that fact. Seems that people who are doing the monarch project would tell people to space out their seed for the monarchs, but.

Adam Baker: All the papers are out there. They just gotta read them. Yeah, yeah, you know, we do this, you know, that’s why a lot of the taller broadleaf species of milkweed are generally more attractive to egg laying females. So one of the studies that I did looked at eight species of milkweed, and in all cases, the taller broadleaf ones are more attractive for egg laying. But then nutritionally we would rear monarchs on all of the different plants. Nutritionally they’re all the same. At least in that study But the mother butterfly chooses preferentially the taller broadleaf ones because they’re probably easier to train to. They have simpler architectures. They have a stronger silhouette, um, and so they’re easier to find.

Mindy : Well, I mean, that really it makes sense if you, you know, from an animal perspective, you know, you want a strong male, you know, that kind of concept for your offspring. So, but I, I just would have never really thought about it in the plant world about that. Thank you so much, Adam, for sharing your insights on this critical issue. Invasive species pose a significant threat, but with the right knowledge and actions, we can make a difference for our listeners. Remember that August is National Tree Check Month. Take the time to inspect your trees and report any suspicious pests or diseases. If you enjoyed today’s episode, be sure to follow us and subscribe for more expert discussions. Until next time, this is Mindy signing off for Timber talks.