Exploring Veterinary Entomology - Controlling Arthropods

Controlling Arthropods for Safer Environments with Dr. Erika T. Machtinger

Dr. Erika T. Machtinger is an Assistant Professor of Entomology at Penn State University. Her areas of expertise include veterinary entomology, tick ecology and Tick ecology and control, filth fly management and behavior, wildlife entomology and arthropod behavior. She runs the Machingter Lab at Penn State and is the author of "Pests and parasites of horses", a one of a kind resource for for equine enthusiasts to learn about pest identification, ecology, and management.

Dr. Machingter shares her vast knowledge and research of ticks, arthropods, horses, cattle and other large animals, even bears! She talks about implementing yard and local landscape level tick control as well as the importance of personal protection.

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Transcript of the Interview

Mary: Hi, this is Mary with Insect Shield, back with our vlog and sharing some great information, and we've got a wonderful guest, Dr. Erica Machtinger. She's an assistant professor of Entomology at Penn State University. Welcome, Erica.

Dr. Erika Machtinger: Hi.Thanks for having me.

Mary: Absolutely. First if you could give us your background, your bio, how you got into what you're doing, and kinda also explain what it is that you do do now.

Dr. Erika Machtinger: Yeah. Sure. So I grew up in Maine on the coast of Maine. And I so very much in the woods. And I also grew up as an equestrian. So I was involved in horses since I was like four years old. And that took me all up and down the east coast. And when I got to high school, I took a class in wildlife and thought that's exactly what I wanna do.

And so my requirement for my undergrad was, it had to be within a half an hour of my trainer in Pennsylvania, which happened to be the University of Delaware. So that's where I ended up. And the University of Delaware's Wildlife Program is heavily influenced by entomology. They're the same program basically.

And so I was thrown into this field of entomology. I didn't really even know it existed at the time and fell in love with it. And So spent some time as a wildlife biologist after graduating, and then went and got my graduate degrees in entomology. And so what I do now is called veterinary entomology.

So I deal with arthropod issues affecting non-human ver vertebrates really. Things that, harm deer or pests of horses or cattle or whatever the animal is. And so I work with all sorts of different critters, wild to livestock.

Mary: And now exactly. Arthropod. What defines an arthropod?

Dr. Erika Machtinger: Yeah, so arthropod is basically it breaks down to jointed link basically. So it is a group of animals that are related by these segmented legs. And so that can be anything crab lobster to tick, to fly and lice and all those other insects. So it's different from So insects are arthropods, but not all arthropods are insects.

So we say arthropods if we wanna have a bigger group of animals that we're talking about. So arthropod, pests of horses includes things like flies antics or arthropod. Pests of people includes mosquitoes which are insects and ticks, which are not. So we use it as a kind of a bigger term.

Mary: Gotcha. And with so I mean you, with your equestrian background, you were probably also dealing with a lot of insects, cuz insects, I understand with horses and in horse farms and barns, they're constantly having to be monitored and protected.

Dr. Erika Machtinger: Yeah. Yeah. So I guess it gives me a little bit of street cred for the horse people that that I've spent some time in their shoes. I had my own farm for a while and had to deal with some of these issues. And a lot of these farm pests are ubiquitous across all livestock and horses and poultry.

And we just deal with them. And I remember that side of me just going, okay, I'll get my fly spray and I'll do my things. And now knowing more about that, now I am better able to address those problems with my own horse. But yeah, it's definitely something that everybody who has a horse that's at a farm has to deal with.

Mary: Yeah. Are and are they in, or the arthropods or insects for horses? Are they hurting them? Are they annoying them or both?

Dr. Erika Machtinger: It depends. So big picture, both. But it depends on the insect, arthropod on what they're doing. So most. Pests that horse people are familiar with their flies. And most of the flies that we see are more of a nuisance than they are pathogen vectors, if you will. They're creating horse, they're stomping, horses are running they're uncomfortable or they're around people's faces, and so that's what we see mostly. There are some flies, like horse and deer flies that most people are familiar with too, that will come in and. Slash and drink.

Basically they slice open the skin and drink, so it's painful. And then there are some flies, like mosquitoes that can actually transmit pathogens like triple E and some of these other encephalitis that we don't really think about. Cause we don't see them that often on our horses, but they are there.

So it's really a range of of problems depending on what you're, what pests you're talking about.

Mary: And ticks can can horses get like Lyme disease?

Dr. Erika Machtinger: Yeah, horses are one of the animals that are actually susceptible. So people, dogs and horses are all susceptible to Lyme disease or the pathogen that causes Lyme disease. And they can also get anaplasmosis which people and dogs can get as well. So they are susceptible to many of the same pathogens that that we can get from tick bites.

Mary: so what? I didn't really, I was just thinking that, so it's only horses, dogs, and people that get these. There's no other like cats.

Dr. Erika Machtinger: cats don't seem to be susceptible. Cattle don't seem, there's still some question about what. Signs in something like a cow that has the pathogen, but they don't seem to have the same level of susceptibility. It's certainly not something that we really talk about a lot with our other cattle folks because they don't, it doesn't impact them like it does dogs and people and horses.

Mary: But then, and then there's the animals that are the carriers, which primarily are my steer.

Dr. Erika Machtinger: Yeah so the For Brelia, which is the pathogen that causes Lyme disease or anaplasma Mice and other small rodents and birds tend to be with what we call reservoir hosts. So that's where the pathogen hangs out, and a tick will bite them, and then a tick could bite in its next life stage a horse or dog or human, and transmit that which may cause disease.

Deer actually don't. Carry the pathogen. They're what we call a reproductive host. So the adult tick will feed off a deer, which allows it to reproduce, but the deer don't have any pathogens. They're important in the cycle, but they're not they're not associated with the pathogens.

Mary: Okay. Interesting. So then, so I think one thing that's interesting that you do a lot of work on is really, as opposed to just protecting like people from getting tick bites, like how do you protect the environment from having less ticks?

Dr. Erika Machtinger: Yeah, so that's a big question. Yeah, cause of landscape level control of ticks. Cuz like with mosquitoes, They're mosquito control districts. They can go out and they can treat the water where the immature mosquitoes develop. Or after hurricane in Florida, they can control the environment by produ by laying down insecticides or whatever happens.

But it's a lot harder with ticks because. They only spend a small amount of their life on an animal and the rest of it's in the leaf litter hidden. And they don't move around a lot. They don't fly. So it's tricky to have this landscape level control. And so what we're working on from a control perspective is can you create bubbles of safety or safer spaces?

Bubbles of safer spaces in parks or at schools. Instead of thinking we're gonna eliminate ticks from the environment because that is a highly unlikely scenario with the tools that we have available. So my group works with host targeted control. So it's, we're trying to treat the animals that ticks routinely feed from to kill the ticks that are on those animals.

And this happened to be also the reservoirs that. Talked about earlier, which are primarily mice and where we are in central Pennsylvania. And we treat the animals and kill the ticks, and that results in a reduction in ticks in the area. And so we're working on trying to optimize that kind of control.

But there are other control methods as well acaricide sprays around homes are incredibly effective. People don't usually like to hear that. They don't like to hear about. Compounds being sprayed in the environment. But the good thing about ticks is that it only really takes two sprays.

Sometimes three, but one spray before the kind of juvenile season of ticks, one spray after, but eight weeks after, and that's it. And you've knocked them down for the year. So it does minimize the potential negative effects especially with non-target like pollinators. That's one of the kind of the best.

Fail safe ways to do it. Like you're gonna knock 'em down. They're not coming back that year. But there's other ways too. There's some landscape management. So if you make sure that you're in a low cut grass area away from the woods keeping the fallen logs and other woody debris away so animals can't hide in it.

So there's some other landscape things that you can do as well. But we are actually quite limited on our tools to control ticks.

Mary: Now and when you do the, with the animals, cause I was, looking into some of your work. So you you try to get them somewhere like the, Mice and the deer that they get like a pyrethroid bath almost, or,

Dr. Erika Machtinger: Yeah. We worked with the deer. It's called a four poster feeder where the deer feed from a station and there's basically paint rollers where the deer put their head through and it treats their ears, which is where the ticks like to hang out with pyrethroids. That has been somewhat effective.

But is incredibly time consuming and expensive to run and with a lot of concerns about CWD with Deer, which is

Mary: What's CWD?

Dr. Erika Machtinger: it's chronic wasting disease. And it's spreading and it can be devastating to deer. And so the congregation areas are not great. Feeding wildlife in general is not a good idea.

Mary: I was listening to, yeah, I guess that's a big I, cause I wanted to ask cause I'm not hunted or been out, but it's what, because when debating that's a big issue. And what exactly is that?

Dr. Erika Machtinger: Yeah. So we feed them corn or in our trials have fed them corn. And we did a study in Maryland which is USDA. USDA developed this technology. And so the study used this technology for better or for worse, but we found that in the two years we had six of these feeders out in. Three different locations.

We put out something like 25 million calories in corn into the environment and that's gotta have some sort of impact on those populations. So there are downstream negative consequences that we're not always thinking about when we develop these. Control methods. So I'm not a big fan of four posters.

So the host targeted control that I use in my lab or that we study is not bait related. It does provide a resource to the animals in the form of cotton. So they line their nests with it. So it is a resource, but it's not a food resource. And we treat that cotton is treated with a fabric binding pyrethroid. And you can buy this for people. You guys have it. 

So exactly it's the same idea. And it binds to those fibers. And then when the mice take it back, they have their babies in there, they're in there. Any ticks that got on them are killed. so that's the way we're targeting those mice without feeding them.

Mary: Right now, is that similar? Cause I know, and that's something people can do with the tubes I've about people like stuff. Okay, yeah, go ahead.

Dr. Erika Machtinger: people can do it with those tubes, they so they can use those tubes. You can't create the tubes. These are EPA registered trial tubes. So a lot of people think, oh, I'll just make my own. No, you can't because you don't have the products that are labeled to make it.

So it's actually legal to do that, and they have not been tested. These have been tested to work in this situation to not to not leach into the environment rub off at the right amount. So we know that these work and, but they're super easy to get 'em mean. You get 'em in amazon.com, 

Mary: So you can buy, right? You don't have to because Yeah, I've read some, someone saying, no, you take a roll of toilet paper or something. Yeah. Okay. You buy the

Dr. Erika Machtinger: one of those, we're trying to squash those rumors cuz no you don't. And cuz people try and grab the livestock permethrin and soak cotton in it and think that works. It's no. It has to like bind to those fat fibers. There's a specific type, so no, you don't, you can't do it on your own, but they're really easy to get and it's one of the only tools a homeowner has to control ticks around their property that they can do themselves, that they don't have to hire somebody to do.

Mary: So for the sprays, that's something you have to hire professional to spray. So you

Dr. Erika Machtinger: and not always there, there are some that you can do 

yourself but there is a certain level of knowledge. You have to know where to spray, when to spray, and so there's a little bit of understanding on how that's done.

Mary: Okay. That so that's something you would recommend people an easy way around their yard to also, help Because I think, yeah, that's a us, the more tools people have, the more things they can do. And then maybe, protect yourselves, to use your insect shield.

But there's just so many tools you need in your, Your toolkit to with all the different insects and all the different protection. And we, and the thing is, ticks too. We don't wanna kill all the ticks too. That's the whole thing with insect protection. What are ticks doing?

Are they doing some good in our world or someone eating them that they need the ticks? 

Dr. Erika Machtinger: So we don't know really. We don't know a lot about ticks and ecology because our kind of interest in ticks came. Up during the early 1980s when Lyme disease just showed up and people went straight to how do we kill 'em? How do we get rid of them? so understanding ticks is very minimal.

Like we have very minimal understanding of what they do and how they do it. And so those are really good questions. Like I. From our own work here, we've got mice that we're looking at how mice respond to, to tick bites and there's some evidence that mice are actually predators of ticks They may be eating a lot of the ticks in the environment that may be valuable for them, which then goes on and feeds the foxes or the owls or whatever. So there's this, great web that we have to keep in our mind whenever we think about controlling or eliminating or whatever we're doing in the environment.

That is very important.

Mary: Yeah, no, I think that's, cuz one thing we have done a lot of work like in the mosquito world and it's you don't want mosquitoes gone. We need mosquitoes too. There's a lot of things that they do. So that's through our whole ecosystem, there's a reason for the most part. Usually these different things have sprung up and they, the, all the different, trees and plants and animals, and it's the whole, goes all the way up.

Dr. Erika Machtinger: It's the whole thing. Yeah. That's why, like for me, from my, when I teach people, I always talk about personal protection more than environmental protection. But I do think it's somewhat related. So using tick tubes as an example, when you have some control, Over your environment and you are the one putting down the tick tubes and remembering to replace the tick tubes, you're more likely to recognize when you're in tick habitat or I'm guessing you're more likely to recognize when you're in tick habitat, cuz you're already thinking this could be where ticks are.

And so you're probably more likely to be wearing those repellants and protective clothing more so than somebody who's just hiring somebody to come and do it for them. I don't know that, but I would assume that some engagement in the process of tick elimination probably has some secondary effects as well.

Mary: Yeah. No, absolutely. Now, one thing too, so I was listening to some other, podcasts you did, you've done, and your work was with bears, so you also studied. If ticks were what you were doing, I guess in a different, you had two studies going with bears, but you were actually tracking, like counting ticks on bears, and did you know before then that there were a lot of ticks on bears, or you're like, let's just see, or how did that come about?

Dr. Erika Machtinger: So most of the research that's been done on ticks has focused on mice and focused on deer because everyone likes to blame them for the Lyme disease issues. But that's really more so because those are the abundant animals that we see and we can get our hands on. I think it's like 85% of all studies focus on those animals.

But ticks, especially in the northeast are somewhat what we call generalists where they don't really care what they bite. And there's a lot of other animals in the forests. So bears were one that we were studying, looking at Sarcoptic mange because we a issue here in Pennsylvania with our black bears.

And we thought since we were going to have these animals in a position where we could do that surveillance, that we should look at other ecto parasites as well. And ticks were one of those we didn't really know, almost, I think if not all, almost all studies that had looked at ticks on bears had been from hunter harvested animals.

So it was one point in time in the fall where, the ticks are. Different life stages of ticks are only out at certain times of the year, so you're only looking at one snapshot. And we were able to look at animals basically all year round except for when they were denning during the study.

So we were able to get a really good idea in kind of this central Pennsylvania area, what was going on with those ticks. And it was actually quite fascinating because we'd had this. In the ecology of ticks, we think small ticks go on small animals and larger ticks go on larger animals.

And we surely did find large ticks on these bears, but we also found all of the juvenile stages they were just in between their toes or down farther on their legs than where the bigger adults were. So it was very, it was a very fascinating assessment, to see how they partitioned.

Mary: Yeah. And then how ticks are just, yeah, they're on so many different animals. And then and I was, I don't know if I heard it right. Was there 20? There are 20,000 bears in Pennsylvania. Was that the number I heard? That's a lot. It seems like a lot,

Dr. Erika Machtinger: It's a lot and they harvest about 25% of the bears every year. So it's a lot of bears that are harvested and a lot of bears that we have in the state, but it's a pretty stable population, a pretty healthy, stable population. So it's it's a great place to do that work.

Mary: Yeah. And when you go, and do you have, when you, because I saw you go do you have to do you put 'em down somehow when you go in to check them? Yeah. 

Dr. Erika Machtinger: So yeah, so we 

work with very 

Mary: talk, but it's

Dr. Erika Machtinger: Yeah, no, that's fine. We work very closely or worked very closely with the game commission and their bear biologists and veterinarians. With their protocols and they were amazing. So they helped us tag onto a study and work with the wardens to find the bears that we were looking for and do a lot of the sedation and monitoring cuz they have so much experience with the animals themselves.

So we could come in and do all the kind of the bug stuff. But yeah, we were pretty involved with. All the stages of the trap capture and the debating and sedation and reversal and all the thing blood samples. And so it was a great, it was a great time. We got to go to all the dens and see all thes and it was a good, it was a fun study.

Mary: No, that's interesting. I'll just a couple more questions. I just actually say go back to horses a little bit. What, are there certain things that you recommend for people that maybe like just to say, okay, here's the basics on keeping your horse protected and just things that maybe you see that you feel like people could do a little bit better or they're not doing that could really make the horse's life more comfortable and not have insects being such a bother to them or potentially, disease laden.

Dr. Erika Machtinger: Yeah, so that's a really challenging question because there are so many different types of pests that. Can affect horses and some horses react differently than others to those pests. Some are much more sensitive than others. Actually, we just wrote like a 400 page book that we just published on all the pests and parasites of horses how to control them and Which was, it was really interesting cuz it was not just North America, but it was other areas of the world.

And learning about all the things that go on in other places was terrifying. It's oh my gosh. But I will say my, my biggest, the biggest piece I think people forget is that they need to know what the pests are that they have a problem with. They assume all flies are the same, even. They look awfully similar, but they're not all the same.

So some traps are gonna work for house flies, some are gonna work for biting stable flies. They're not all gonna work for the same species, they're not gonna work at all. For horse and deer flies is a completely different type of control. So really understanding. What you have is important. Then doing everything you can to prevent those pests from being a problem to start with.

Sanitation at the farm, manure management. Cause once they get a foothold, it's really hard to get rid of them. So being very clean. And doing some of those manure management practices can be super helpful for some of the pests. One of the things we're, we've been struggling with is trying to think of good ways to help protect horses from ticks really.

We did a study last year to get an idea of what ticks were on horses when they were on horses here in Pennsylvania and then did a kind of a separate study. Looking at pyrethroids and if we could use pyrethroids in kind of an automatic applicator, like the four poster, but for horses, cause we could feed horses and that's okay.

Basically, could you throw them their feed and have them treat themselves every day or something along those lines. It turns out. At least in the way we were looking at it, probably not because the pyrethroid levels that you need to really impact ticks are way too high for horses and would cause some pretty severe skin sensitivity

Which has now led us to this treated clothing idea for horses. And so that's actually something I've been recommending a lot to people. Like I've been using it on my horse. I've been recommending it to folks who ask this technology is out there. It works for people. We don't know if it works for horses.

We're right in the middle of a study now to try and figure that out, but it can work for so many different types of pests, right? Just not just ticks, mosquitoes and flies and so many different things, and it takes away that. Having to put on fly spray all the time, which doesn't work anyway.

And so like it takes that away and you just have this passive repellent or passive treatment on your animal and it seems like such a better solution. So we'll see. We'll see what our results say in the way that we're doing it. You can buy some products that have this

Mary: Yeah, we have, we've worked with people making horse sheets and fly and things, and

Dr. Erika Machtinger: Yep. Exactly. So there's insect shield has it? I think No fly zone

Is that different? Yeah, that's the different thing. Or, so there's some other folks too. And then I spoke with you guys not too long ago about being able to send in your horse's own stuff and get it treated with insect shield and it's it's an amazing opportunity.

Every spring you just send it in, get it treated and get it back

Mary: Yeah, and I was just talking actually, cuz I was just doing a presentation with a group of Minnesota and they asked, and I confirmed with our guys, as long as it's machine washable you can send it in and I think it's $13 or

Dr. Erika Machtinger: Yeah. It's like easy. And I love that idea and I think it's just such a wonderful opportunity to at not attack, it's very passive, but to handle many different pest issues at the same time.

Mary: Yeah. And exactly. It works the same for people, and like you said, it's with hor, it's horses, dogs, and we do dog stuff as well because it's horses, dogs, and people that are affected. No, it's, I didn't realize it was just those three, that, that are those three. Animals or mammals

Dr. Erika Machtinger: And it, it's, a great thing that you guys have, because currently the sprays that we can use for people are not labeled for horses, so we can't use

Mary: Interesting. 

Dr. Erika Machtinger: Yeah, so it, it has to be this way. So it's awesome that you have this available.

Mary: Yeah. No, that's good. No thank you for that. No, it's really, that's, it's really interesting. Just the things that you're working on and we love sharing the word about, people just different ways that we can all work to protect our environment and our folks. And I just, one la I just saw a little news alert that Pennsylvania's is maybe passing a law for schools about.

Making sure everyone that all the, at the school, someone knows how to remove a tick and that the tick must be then saved, which is a huge thing. I know that we come across people, I never knew you can save the tick and get it tested, that they might put that into law, which I think is a big, that could be a big thing for, just people understanding about ticks and how it has to, that you have to know how to remove it and that saving it is such a critical point if you're worried about potential disease.

Dr. Erika Machtinger: Yeah, I think it just understanding that risk, kids being at risk, where they're at risk, where they may be picking up these ticks and I think that, that coordination with the schools is gonna be hugely important.

Mary: Yeah. No, it's interesting to see. Yeah. They're, being proactive on that is great. I thank you so much for sharing your information. Now, this book, is that something that you're, is it on sale for, to the general public? Is it more of a scientific journal or what's

Dr. Erika Machtinger: No it wasn't. So I had this dream to, to write this book. And my PhD mentor a couple years ago was like, we should do this. And I was like, okay, yeah, sure, whatever. But got a publisher to sign on and we wrote the book and it's very much a practical. horse person friendly book.

It has a section. It's broken down to this is what they look like. It's very picture heavy. These are some options for control. It's all science-based, but it's all very digestible. Then there's a sec separate section for kind of the vet part. So if you've got. Veterinarians or people who may not be as familiar with some of these things that they can go through and look and a whole thing of continuing resources for all these pests.

So if you're continuing education, so if you're interested in learning more, there's a lot of resources. Yeah. So it's, it was supposed to be a very practical guide. Anybody could pick up, read and go to the chapter they need and look and see what it is and handle their pest

Mary: Excellent. And what's the name of the book?

Dr. Erika Machtinger: It is called pests and parasites of horses.

Mary: Okay, we'll come we'll maybe after, cuz we'll get you, but we can put a link to it

Yeah, that'd be great. Excellent. Wonderful. Thank you so much for sharing and if and hopefully we can talk again soon and hear what you're up to and other new research that you're working on.

Cause it sounds like you're really you're in there, you're doing it yourself, like really doing this stuff. It's not, it is really cool.

Dr. Erika Machtinger: Doing a lot of stuff. Yeah. Really. We have a good time.

Mary: That's awesome. All right, thank you so much, Erica.

Dr. Erika Machtinger: Sure.