Unexplainable - Should we really kill all the lanternflies?

Episode Date: June 17, 2026

When an invasive bug landed on the East Coast, people embraced the order to squish it to death. But what has all that squishing done to us? Guests: Julie Urban, professor in the entomology department at Penn State; Chelsea Batavia, community engagement coordinator with a PhD in forestry For show transcripts, go to ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/unxtranscripts⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ For more, go to ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/unexplainable⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ And please email us! ⁠⁠⁠[e-mail]⁠⁠⁠ We read every email. Support Unexplainable (and get ad-free episodes) by becoming a Vox Member today: ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/members⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ Thank you! Learn more about your ad choices. Visit podcastchoices.com/adchoices

Support for this show comes from Fetch Pet Insurance. Do you have a pet? Every six seconds, a pet owner in the U.S. gets hit with a vet bill of over $1,000. And it's almost always an unwelcome surprise. That's where Fetch Pet Insurance comes in. Fetch is the most complete pet insurance. Get paid back up to 90% of vet bills. You can use any vet in the U.S. and Canada.

All vets are in network. Go to fetchpet.com slash save right now for your free quote. That's fetchpet.com slash save. Support for this show comes from fetch pet insurance. Do you have a pet? Every six seconds, a pet owner in the U.S. gets hit with a vet bill of over $1,000. And it's almost always an unwelcome surprise. That's where fetch pet insurance comes in. Fetch is the most complete pet insurance. Get paid back up to 90% of vet bills. You can use any vet in the U.S. and Canada. All vets are in network. Go to fetchpet.com slash save right now for your free quote. That's fetchpet.com slash save. Okay, I have returned today to a scene from my past. This is where I was standing

last summer when I saw a bug skittering up this tree trunk. It was a very distinctive bug. It has a Pokedodati sort of wing with red underneath. This, unmistakably, was a spotted lanternfly. The spotted lanternfly may be pretty small, but it has the potential to cause big problems. The invasive species showing up around the tri-state area this summer. These gray and black dotted bugs that are said to be a destructive pest that feeds on more than 70 different plants that are critical to the state's agriculture. So I knew what this thing was. I had seen these many times before.

They are all over Brooklyn. They took off around 2020, 2020, 2021. And so I knew what I was supposed to do in this situation. Authority say, if you see one, you're asked to kill it. You heard right, kill the bugs. So I ran after it. I ran up to this tree and I remember I tried to stomp it like on the tree, which is hard to do. So it got away from me, and I was going after it again.

And then this is what I remember most. This woman yelled at me from down the street. And I don't remember exactly what she said, but the spirit was like, yeah, get it. Get the lantern fly. And this is not the first time I've had that kind of interaction. Like, this is definitely been the vibe. Welcome to New York, guys, where citizens have turned merciless mercenaries to protect nature. Your friend Lantern, Paul, could ask him?

about it. Ask him what happens when you're in New Jersey. Huh? No, are he in here? I wonder where he went. Maybe under my f***ing shoe. People really, really got on board with just the mass murder of bugs. And I, in that moment,

was actually feeling really ambivalent. Because, like, on the one hand, it did feel good to be a part of this big civic project with my neighbor. And also, it is satisfying to kill one of these bugs. Like, it feels like you're almost scoring a point in a game But I also kind of wanted to say to her, like, isn't it weird that we're all just happily participating in this big project that is about killing living creatures and we're like giving each other high fives over that?

Something about it just feels also really bad. And I did not say any of that. I was kind of just like, oh, it was a lanternfly. But now, lanternfly season is coming again. there's a chance the lanternflies are above me in this tree right now, like getting ready to hatch. And I'm once again going to be faced with essentially a moral question of a kind that comes up in conservation all the time, where we're forced to choose between different types of beings and their lives. So the question is, should I personally be killing these invasive lanternflies?

And also just, what is the right way for any of us to think through that? kind of decision. One of the first people to learn that the lanternfly had arrived in the United States was a scientist named Julie Urban. An old acquaintance of hers unexpectedly left her a message. You know, Julie, this is Leo. Call me back. And like, they found it.

They got it. It's here. I knew instantly. You knew you just from that? I haven't talked to the guy in like years, right? You were like, it's the lanternfly. It's got to be. Totally.

Wow. Oh, my gosh. How'd you feel? Freaked down. out, totally freaked out. The lanternfly had been on Julie's radar because she studies the group of insects that it belongs to, the plant hoppers. And she got into that work, not because she was interested in invasive species management, but because she was into evolutionary biology. And she just thought that these bugs were incredibly cool. Cicadas are great, everything. But if you've seen one,

seen them all, okay? They kind of have the same, like, body shape and form. But plant hoppers, they're extremely, we call it morphologically, but body shape, diverse, right? One of them, its common name is the peanut-headed bug, because it looks like it has a peanut on his head, right? Okay, good. Like, who has that, right? And some of them shoot wax out their rear ends. And I'm like, wow, I'm like, they shoot wax out their butts. I'm in. But, like, even if you're in it for the wax, you do have to stay up to date on bugs you study that could have a real-world impact. So that's why Julie had her eye on lanternflies. Because around 2004, they had landed in South Korea, and they did a lot of damage there, mostly to grapevines, but also to apples and other tree fruit,

to ornamental trees and timber trees. They have this straw-like beak that sits along their abdomens, and they use that to suck on a part of the plant tissue called floam, which carries sugars that are created by photosynthesis. That sugar is what fuels its growth, it allows it to reproduce, that kind of thing. And so it's... But it's also famously delicious. Exactly, right? And so the insects are stealing that.

So Julie calls Leo back, and she learns that the lanternfly has indeed been detected in the United States, specifically in Pennsylvania. And a little while later, in the spring of 2050, she heads up there with a team of people who are trying to figure out what to do. We went to the landscaping company where it was thought that that was like ground zero, so to speak. I had never seen a landscaping company at this scale. What did it look like, like greenery or? Greener. Well, piles of stone, like really from around the world.

The lantern flies seemed to have arrived on one of those piles of stone, a shipment from eight. Asia. These bugs are unusually good at hitchhiking. And when the team looked closer, they found old egg masses on the grounds of this landscaping company, meaning that actually, the lantern flies had probably arrived more than a year earlier. And they also noticed that lantern flies seem to be feeding especially on the tree of heaven, which, despite the nice-sounding name, is actually itself an invasive species from Asia. Now, non-native species arriving in new places, that is not always a problem. Like, honeybees are not from North America, nor are most earthworms.

But the worry is that a non-native species with no natural predators can get out of control. They can displace other species, or in the case of lanternflies, they can kill a lot of trees. So Pennsylvania took some steps to manage the lanternflies. They put some areas of the state under quarantine so that things like landscaping materials had to be inspected before they could move. They cut down some trees of heaven, they used insecticides, and at first, the population is not exploding. But then comes 2017. Julie now has a job at Penn State studying lanternflies, and a grape grower has agreed to test some insecticides at his vineyard. As part of that, he leaves a couple of rows of grapes untreated for comparison.

And so we go out and it was raining cats and dogs. You know, we're in the back of this grower's pickup truck. And we're driving through this vineyard. And the support posts at the end of the rows, we just see them post after post slackered with land or fly egg masses, like a lot. Wow. And we're all, oh my gosh. Like, you know, and so it, if the movie Jaws, you know, when Brody first sees a shark,

I think we're going to need a bigger boat. Julie described 2017 as one stomach drop after another. She'd been working with a grad student on all this, and one day the student calls her. She said, Julie, I'm out here. I'm going to the Walmart. They're flying into Walmart. And I'm like, what that? What are you guys doing here?

And then she called me again at that vineyard. He also grew apples. And she called me, she said, Julie, I'm at the vineyard, and they're flying over into the apple trees. They're hitting my car. And we had never seen them on the apples before. The general public gets wind of all this, and some of them begin to take matters into their own hands.

One enterprising individual goes after some lantern flies with a blow torch. Try to surprise attack him here and just go out of them. And some people who are hearing about the rise of lantern flies start getting angry. They say, why didn't you just nuke them at the beginning? Everything you did was wrong. Julie and her colleagues, including at the Pennsylvania Department of Agriculture, they had been balancing a lot of concerns as they figured out how to deal with the lanternflies.

Like, they could have just torched the infected area with strong, nasty insecticides. But, you know, they already were using powerful insecticides. They were just trying to do it in a way that didn't kill too many other bugs. But the containment measures didn't totally work. By 2018 and 2019, despite the quarantines and the pesticides, the lanternflies are really on the move. They spread to the city of Philadelphia, about 6,000. 60 miles away from where they were first detected. And in the summer of 2020, amid everything else going on, they are exploding.

Invasion of the spotted lantern flies in University City, and it looks like ground zero is this Chipotle at 34th in Lancaster. There's footage of the bugs absolutely blanketing the sidewalk at the entrance of this ill-fated Philadelphia Chipotle. There are photos of the bugs wrapping around the trunks of Pennsylvania. Pennsylvania trees, which is very creepy, though also oddly beautiful. And ordinary people in Philadelphia are fighting back, as they have been told to. In the summer of 2020, the Pennsylvania Department of Agriculture posted on Facebook about the lanternflies saying that you should, quote, squish their guts out anytime you see them, unquote, a kill order. And people get very into this. Stomping, squishing. There are reports of kids in Philly going after them with

skateboards. And it did seem to me that the point of the various lanternfly campaigns was to inspire us all to action. But I did wonder, like, why? One thing I've been curious about is, like, is the Stompit part of the campaign actually to help bring down populations? No. Nope. So what is it for then? It's again, if you don't kill it, you're going to carry it. Now, we don't have good data on this, but it doesn't seem like the individual stompers have had that much of an actual impact on lanternfly population levels. Other mitigation measures are way more effective. But Julie and the Pennsylvania Department of Agriculture are really focused on whether the lanternfly will spread.

Like, you stomp it so it doesn't try to hitch a ride with you in your car. And if you look a little more closely, you can see that the public outreach campaigns in Pennsylvania and eventually New York do include information about this. Like, make sure to report these bugs if you see them outside of the quarantine zone. In Pennsylvania, you can call the hotline at 188-4 bad fly. A lot of their communication is also about scraping away egg masses, which is more efficient than stomping individual bugs. But when I started to hear about this, it seemed like some of that nuance had gotten lost. People were kind of just stomping with abandon, even with a sense of glee. And like, we were sending children off to do this.

Girl Scouts love taking action. They love finding ways that they can help out in the community. And one of the ways that Girl Scouts are showing the love to Parks today is through a little bit of a lanternfly squishathon. But there were also signs that people were conflicted about the kill orders. One friend told me that in the summer of 2021, she saw someone running after a lanternfly, yelling out, the New York Times told me to kill you. I personally know a couple of people who gave up stomping. And the question even made it on Jimmy Fallon, where comedian Kate McKinnon was making an appearance.

And I saw this baby on the street. And I was like, oh, my God. This moth. What? It's like sepia-toned wing. Fishnets, basically. Basically, it's gorgeous. Peek of red with polka dots.

Like, this is a burlesque dancer. But she promises that now that she knows it's invasive, she's going to kill it. No, we're supposed to. We're supposed to, and I will. I will kill the next lanternfly. But take a photo of it. You will.

Oh, my God, you're winking. You're not going to do it. I will. I will. I will kill the next. If you didn't catch that, Kate is saying she's going to do this, but then overtly winking at the audience, like letting us know that she's crossing her fingers behind her back. People were starting to wonder why exactly we had to kill these gorgeous burlesque dancer bugs. And actually,

the science was getting a little more murky on this question, too. The initial worries about how the lantern flies might kill all these trees and crops, those did not pan out. As of now, in the U.S., the bugs are really mostly a problem for grapes, and therefore for grape growers. Though Julie told me, in her mind, there is still urgency around making sure that the lantern flies don't expand to new places. So if heat makes them develop, they're going to develop earlier as they move south. That could mean more time to feed on Georgia peaches, or maybe on the many grapes in my home state of California. So even though things have to be able to. haven't been as bad in the Northeast as they initially feared, it is still possible that in other

places, it could be worse. These past couple of summers, I have shared Kate McKinnon's ambivalence about stomping lantern flies. And I have felt especially ambivalent about the kill orders and how happy we all seem to be to comply. But this year, I don't know. I wanted to face my ambivalence head on. It is really not the biggest deal in the world.

So I was like, I should actually just decide once and for all what I'm going to do here. Make a moral choice that I can live by. Do you think it's morally right for me to kill lanternflies? Yes, because I think if anything, it can only help. Julie doesn't like the idea of killing living things, and she knows better than anyone what cool creatures lanternflies are. But she was like, to do it. I mean, this is, it's kind of like, as humans, we've manipulated our environment so much,

you know, and ethically, it's our responsibility to try to fix that or keep it from getting worse as much as we can, you know? We have to do our chores environmentally, right? And a lot of times they're distasteful. And this is one that's very distasteful. I totally see how Julie landed here. And yet, even with what I had now learned about the science, I felt like there were still ethical questions here that I wanted to think through more deeply. Ideally, with the help of a moral philosopher. And when I did, I learned more than I had bargained for about the ethics of conservation and of decision-making in general.

That is after the break. Support for this show comes from Fetchpet insurance. Do you have a pet? Every six seconds, a pet owner in the U.S. gets hit with a vet bill of over $1,000. And it's almost always an unwelcome surprise. That's where Fetch Pet Insurance comes in. Fetch is the most complete pet insurance. Get paid back up to 90% of vet bills.

You can use any vet in the U.S. and Canada. All vets are in network. Go to fetchpet.com slash save right now for your free quote. That's fetchpet.com slash save. Visit betmgm casino and check out the newest exclusive. The price is right fortune pick. BetMDM and GameSense remind you to play responsibly. 19 plus to wager.

Ontario only. Please play responsibly. If you have questions or concerns about your gambling or someone close to you, please contact Connects Ontario at 1-866-531-2,600 to speak to an advisor. Free of charge. BetMGM operates pursuant to an operating agreement with Eye Gaming Ontario. This spring, denim gets a softer, lighter update. Introducing Old Navy's drapey denim wide leg, a new fit that moves with you.

It's everything you want denim to feel like for summer. Easy, breathable, and effortlessly cool. With a fit that creates natural movement and a wide leg that feels modern, not overwhelming. Plus, that signature, wait, for this price, moment. Old Navy's drapey denim wide leg. I read several different papers and articles. as I was trying to think through my decision about whether or not to kill lanternflies this summer if they should be so unlucky as to cross my path.

And there was one that I kept thinking about by an author named Chelsea Batavia. She lives in Washington State. The lantern flies have not made it there yet, but I told her the whole story. Oh, boy, what a mess. Chelsea now works in government. She is representing her own views here, not the state of Washington. But back when she was a PhD student, studying ecosystem management and environmental ethics, she got interested in moral dilemmas in conservation.

Because, you know, mostly people who care about conservation are trying to do the right thing. But sometimes they face conflicting moral demands. You know, it's challenging. Should we be killing Bardell's to save spotted owls? This is something that happened in the Pacific Northwest starting in 2013. and the images of the bodies of invasive barred owls that had been killed in the name of conservation, they made people uncomfortable. And Chelsea gets that.

You know, like, I have kind of a strong intuitive response to like, no, we shouldn't be killing anything. Don't we say that we care about nature? Don't we say we care about wildlife? Right, and killing is bad. Like, that's the first thing you learn. Exactly. It's like, thou shall not kill. But then when you dig into like the details, because that's the thing.

Ethics, we can think about it at an abstract. but at the end of the day, we are making decisions. We're acting in the context of particulars, right? And once you get into those particulars, these like high-level, yes, we should kill or no, we should not kill, that just doesn't, there's too much nuance. So Chelsea started thinking deeply about the ethics of this kind of situation. And she agreed to help me think through my version of that,

the lantern flies. I guess a first response is that I think it is grossly inappropriate for anybody to be killing gleefully. This seemed like a very reasonable place to start. Like, a lot of my discomfort is about how the killing sometimes feels like this big collective game. But if you put gleeful killing aside, there is still the question of killing at all. And Chelsea was like, okay, we could get into the world of normative ethics, which is about helping us choose what to do.

It's got three big branches, three big frameworks we could consider. Number one is consequentialism. Consequentialism says the right action, very, very coarsely put, the right action is the one that produces the best outcomes. So the focus is on what happens. In the case of the lantern flies, there is one big, obvious outcome. We're killing life. We're killing insects. We're killing bugs.

These are little lives, right? Yeah. Many smart people do think that insects are conscious and feel pain. So that is in the don't kill them column. But of course, on the flip side, humans are conscious and feel pain, and humans are harmed by lanternflies, especially humans who grow grapes. So that is in the kill them column. Chelsea also pointed out a whole world I hadn't thought of, also in the kill them column, that is like, if I stomp on lanternflies now, then I may be preventing people in California or other states from having to make this decision. and I'm also preventing the lanternflies' future children from also being killed.

But then it's like, do it, how do we weigh the value of a potential life that never was against the life that is here right now? So like, to me, that's, I'm just, I think that consequentialism is a useful tool for thinking through things. But I, like, I'm very rare like going to, like, put a flag and I'm going to be like, yes, this is the way we should be thinking about things. And you're pointing out, there's just a lot of uncertainty about outcomes here. There's a lot of uncertainty. And there's a lot of types of outcomes that can't be quantified. and even if they could, they would not be comparable. So, you know, I think that that's not helpful for you making your decision to try to make a calculation based on the best outcomes.

I got to say, I was relieved. I think part of me thought I had to have all the information in order to responsibly make this decision. Like, read the appendix of all the studies or something. But actually, that is not necessarily required in order for me to make an ethical choice. might even be a way for me to avoid the decision because it's hard. Though Chelsea did say it is, of course, very important that scientists keep learning more about the outcomes. Like, if it turns out that the lantern flies making it to California is definitely going to cause mass famine, that could really change my moral calculation.

But for the moment, we left consequentialism aside. The second frame Chelsea told me about is deontology, which means the science of moral duty. It focuses on the intention behind my action. Why am I doing it? When you talk about feeling like you're participating with your community and doing something to support your hometown, that to me sounds a lot like more of a deontological claim. You're thinking about your intention. Your motivation is not to be cruel and kill lanternflies.

Your motivation is to be a good neighbor to make that connection with your neighbor. So, you know, to me that's not irrelevant. That is something to pay attention to. All right, so we put those issues into the mix. And then framework number three is called virtue ethics. It is a really old branch of normative ethics, which essentially says that virtues should guide your actions. So Aristotle talked about virtues being things like, you know, courage and temperance. And so the idea is then as you are moving through your life and you have to make moral decisions, you do what a virtuous person would do. So, like, you know, courage and temperance. So, like, the idea is then as you are moving through your life and you have to make moral decisions, you do what a virtuous person would do. So, So, like, the reason why this was not very popular for, you know, as we got into the Enlightenment, we were looking for rules, it's like, that's not a rule. There's definitely something to be said for rules. But this flexible framework seems useful to me, too. Because there actually are multiple reasonable ways to think about this.

Like, maybe a virtuous person would take on the task of killing bugs on behalf of their community. Or maybe a virtuous person would decide the principle of protecting less. is the most important thing here. Gleeful killing of creatures could be a slippery slope. The important thing is to think about what is actually good and then try to take action to get there. I also realized I had been assuming that I needed to make like an ironclad decision here that I can never violate,

I think because I wanted to make sure that I wasn't letting myself off the hook. But it's also true that there's no law that I always kill lanternfly. or that I never do. Maybe I'd been looking for something overly simple. I think that when I see work in conservation ethics and a lot of ethics in general, it tends to be quite definitive. It says, like, you know, this is right, this is wrong.

And I just, I really like language that gives us a way to say that it's not that simple. When Chelsea was doing her PhD, she felt like she really needed some language like that to describe these conservation moral dilemmas. like the one with the invasive owls. So I started snooping through some really gnarly moral philosophy stuff. Looking for like a word to describe that feeling.

Looking for if there's any scholarship that acknowledges that like this is a thing, that, you know, ethics is not a matter of righteous. Like, yeah, I got that. Like gold star for me that there's this gray zone. And that's how I found this language around moral residue. Moral residue. It describes the feeling that that, left behind when you make what you think is the best ethical choice, and it still just feels bad.

It's an emotional response, actually, which is super interesting because moral philosophy puts a lot, you know, high premium on the mind, on rationality, on logic, on thinking, and deliberation. So it was really interesting to me that something that is recognized as an emotional signal is given language. allowing my emotions into the room, that was actually really clarifying to me because I'd kind of been feeling like if I still felt bad about my decision, maybe I just hadn't yet arrived at the right decision.

But actually, maybe I'm just going to feel bad about both options, and I still have to choose. One thing moral residue is not meant to do is let anybody off the hook. You're going to have to kind of sit in your own moral responsibility and decide what you're going to do. There is no, no action option, You either kill them or you don't.

And I think you're probably going to have to sit with some sort of discomfort either way. But I think that wading into the complexity is the right way to do things. That's like a responsible way to be as a free, willing, moral agent in the world. Like if that's not what we're doing here as people, then I guess I'm not sure what we're doing. By the end of our conversation, I had enough of a sense of Chelsea to know that she was not going to tell me what to do here. But I did ask her, What would you do if they do get to Washington? Yeah, if they get to Washington, I'm definitely going to learn more

and try to use my best critical brain to understand kind of how the research was done and what it means. But I think that my, this is where I would acknowledge my unwillingness to accept that personal burden of taking a life. I wouldn't do that. Well, yeah, like you're feeling like I wouldn't stop them. Yeah, and that would be a loss. You know, because I would recognize that I do have an obligation for all the reasons that we've already talked about.

But, yeah, I think my reverence for life is probably a little bit too strong of a signal for me at this point. All right. I'm back on this block near my house with this tree that had a lanternfly scuttling up at last summer that I tried to kill. And I've made my decision. When the lanternflies come out this summer, I am going to stomp them. that is not where Chelsea landed for herself, but I think she modeled a way of making the decision that accepts the moral residue,

makes the choice based on what feels important to her. And for me, I think the communitarian value of helping people in my region is just really important to me. But I also accept that means I'm going to be taking insect lives and that my individual actions actually don't have that much of an impact. Like, I don't think I should kid myself about that. But there is also one big thing that I'm going to force myself to do differently from last year, which is that this time if someone comes up to me and is like, yeah, get them.

I think I'm really going to make myself be like, I kind of hate doing this. Like I've decided to do it, but it's a rough tradeoff that we're being asked to make, right? Like killing bugs does not feel good. Because I do think that maybe having a weird, honest conversation with a stranger about something that matters is also a good. in itself. This episode was produced by me, Sally Helm. It was edited by Lisa Soap. Christian Ayala did the mixing and sound design.

Meredith Hoddnott runs the show. Melissa Hirsch checks the facts. Noam Hassanfeld, Valerie Shankman, and Joanna Solitharov are wondering what it is really like to be a bird. And Bird Pinkerton immediately pulled out the broken guitar when Flapton hissed, shh, not here. They have ears everywhere.

And he led down a narrow passageway, away from the outside passageway, deeper into the station. Thanks as always to Brian Resnick for co-creating the show along with Bird and Noam. If you have thoughts about the show, please send us an email. We love reading them. We are at Unexplanable at Fox.com. You can also leave us a review or a rating wherever you listen. That really helps us out. And if you are into supporting the show and all of Vox in general, join our membership program.

can go to vox.com slash members to sign out. Unexplainable is part of the Vox Media Podcast Network, and we'll see you next time.