Science Friday - Bedbugs Have Been Bugging Us Since Before Beds

Episode Date: June 10, 2025

Bedbug infestations are not just a modern problem—these pests have been with early human ancestors for 245,000 years, causing problems long before the invention of beds. Lindsay Miles, an entomologist at Virginia Tech, has found that changes in bedbug population size mirrored those of humans, proving they might be our first pest. Miles talks with Host Flora Lichtman about our history with bedbugs and why they’re such prolific pests. Plus, the discovery of a new wasp that catches its prey… with butt flaps. Dr. Lars Vilhelmsen, curator at the Natural History Museum of Denmark in Copenhagen tells us all about it.Guests: Dr. Lindsay Miles is an entomologist at Virginia Tech. Dr. Lars Vilhelmsen is a curator at the Natural History Museum of Denmark in CopenhagenTranscript is available on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Hey, I'm Flor Lickman and you're listening to Science Friday. Today in the show, our oldest and least welcome roommates. I'm not going to lie, they give me the egg. However, their genetics are really, really interesting. A certain pest we love to hate. We fear them. We obsess over them. We can't resist turning them into sitcom plot lines.

Good afternoon, ladies and gentlemen. I'm sorry to bother you. My name is Jack. and I have bedbugs. If Jim has bedbugs, that means they're everywhere. I can't risk them coming back to Shrewd farms. Our biggest attraction is our 200-year-old mattresses. That's our trademark.

Yes. Trademark. Billy Bedbug? Bedbug? You expect Nora Desmond to appear in a film with a bed bug? Cimex lectillarius, the bedbug. It's almost always the villain in our narratives. But what's this little pest backstory?

Where did they come from? How long have we lived together? It turns out their history with us is ancient and predates even beds. Joining me to give a history lesson on our long relationship with bedbugs is Dr. Lindsay Miles, entomologist at Virginia Tech in Blacksburg, Virginia. Lindsay, welcome to Science Friday. Thank you for having me. I'm very excited to talk about my research today. And I'm very excited to talk about bedbugs. Let's start with how long they've been around.

Yeah, so Symex-Lectilarius as a species has been around for well over a million years. So we are talking definitely before beds were a thing and even before humans were a thing. They predate us. They definitely predate us. What were they eating before they were eating us? So likely they were eating some sort of dinosaur, maybe the earliest form of a mammal, but likely a dinosaur. I mean, it seems like slurping on a dinosaur might take different equipment than slurping on a human. Like, have they evolved over time? Do we know?

So I'm sure they've evolved a little bit over time, but they have a proboscis. So similar to something like a mosquito, right? It's that like long, stabby, sucky bit. So they're able to stab through the layers of skin, whether it's a reptile, whether it's a human. and then they're able to slurp up the blood after they've done that. When does their story begin with us? Yeah. So around 245,000 years ago, they had jumped from some sort of dinosaur onto a bat in those millions of years.

And then 245,000 years ago, they jumped from bats to human. And if you think, okay, 245,000 years ago, that's well before mom. modern humans. So we're talking about early human ancestors. So like Neanderthals and the other variants of early human ancestors too? Absolutely. So one of the things we always think of with Neanderthal is, oh yeah, they were, you know, a bunch of brutes living in caves. And, you know, that was partially true. They were absolutely living in caves. And that's how they started to get bedbugs from the bats that shared the caves with them. So likely, you know, a subset of these bedbugs dropped from the bats onto the Neanderthals and really enjoyed the meal that they were

eating off of them. Sure. Why not? I mean, the thing, though, is I think of bedbugs as wanting the finer things in life, like a bed. Like, where did they live when they were living with early humans? Yeah. So they lived in the cave with them on, you know, whatever. kind of surface that they were sleeping on. You know, early humans have been making bed-like structures. So definitely they got their name in more recent years when, you know, most people have what we consider, you know, currently a bed. But there were always kind of designated sleeping areas, and that's where they would hang out. Have any other bugs lived with us for this long? Yeah. So one other bug that we.

have a really tight connection with is human head lice. Uh, but the thing with head lice is that they're always with humans and previous research hasn't really seen the association with cities like we do with bedbugs, right? When your child goes to daycare, they come home, they have head lice, you give them that treatment and it's over. But with bedbugs, you get one bedbuck. takes is one pregnant female, and now you have an insane infestation. Yes, we know. Okay, so what about cities?

Like, as people started forming cities, what happened to bed bugs? Yeah. So after the kind of Neanderthals started coming out of the caves, they started intermixing with humans. And again, you know, they're sharing beds, so they're sharing bed bugs. Then humans start having these early villages, these bed bug populations aren't super high yet because they're these small isolated populations. Then in the early human history, we started building cities, right? So you can think ancient Egypt, Mesopotamia, there's lots of archaeological evidence of early cities. As soon as we start building cities, we start having these massive populations by massive

in, you know, early human history, we're talking like 2,000, 3,000 people. But again, that's more than a family of five for the bedbugs to be able to start chomping on. So as our population density increases with city, so too does the bedbugs. Do we see bedbug fossils in ancient archaeological sites? We do. There are some early evidence of at least maybe not our specific. bed bug, but there are kind of their earlier ancestors in fossil evidence. How else do you track them over time? Is it just fossil evidence or do you look at their genes, too?

Yeah. So one of the really cool things is your DNA holds a ton of history, not just your personal history, but your entire species history. And so that's actually what I'm looking at in the study that we had. I am looking across the entire genome of both bat and human bedbug lineages. And what's your lab like? I mean, do you have like a closet full of bedbugs? We have a freezer full of bed bugs. Someone's nightmare, your dream. Right. Exactly. Yeah, we have thousands of bedbugs in little sample containers in our freezer. And what we do is we extract the DNA out of those.

and then we send it off to sequencing. What about pesticides? How have bedbugs changed with the invention of pesticides? Yeah. So they're really an interesting species to look at because they're really highly inbred. They're highly inbred even though there's so many of them? Yeah. So your infestation, well, maybe not your personal infestation.

No. No, Lindsay, please don't tell me. But any given infestation is actually because it's sponsored by like one female, then you have offspring kind of getting together with each other. And so you get really high levels of inbreeding, which means that any given infestation has very low genetic diversity. But despite that, they are really amazing at gaining mutations that make them insecticides. decide resistant. How can they do that? If there's low genetic diversity, how are they good at getting mutations? Yeah. So mutations are a thing that happens in everyone's DNA all the time. Okay. And so what will happen is a random mutation can pop up. And because it is super beneficial, it will stay in a population.

So it's quantity. There's like enough bedbugs that you're going to get some mutations. Exactly. And because something like an insecticide resistance mutation is so beneficial, it's likely every starting kind of propagule of an infestation has that mutation. Right. It only takes one kind of really good mutation and then it can end up spreading to everything. Was there a time when we thought we could wipe them out? Oh, absolutely. So back in the 1950s, we used this fantastic, thing called DDT. There's lots of really cool media out there. You can look into where they say like DDT is good for me. Is it though? Yeah. So we found out not long after using it. It was really not good for

people. And we thought we had eliminated the bed bug populations. We, you know, we didn't see them in these super high frequencies. So we thought, we got this. Unfortunately, we didn't get this. They, They had within five years of putting down that pesticide, there were populations that show mutations that are resistant to DDT. So then after that kind of five years, those small populations become large populations. Oh, super bedbugs, basically. Oh, yeah, absolute super bedbugs. And then as those populations increase in that same time frame after the 19th,

50s, global human travel became a thing, right? And it's something that many people can do. It's not just for the ultra wealthy. Little side note, the ultra wealthy are also people who can spread bedbugs. So when we start traveling globally, we are moving bedbugs along with us. And now they're also resistant to insecticides. So we've got these now super bugs that we have moved around all over the world. world. Wow. You know, bedbugs are so maligned. I want to see them through your eye stalks. Do you have a special appreciation for them? I really do. So I mean, okay, I'm not, I'm not going to lie. They give me the ick, right? When I see live bedbugs, because sometimes people will send us samples, I definitely get the ick. However, from a genetic lens, these are a really interesting and unique

species. You know, it feels to me kind of insane to call them bedbugs since, you know, they had a whole life before beds. They sure did. How should we rebrand them? I think they need a new name, and I think we should try to come up with it. Yeah, I mean, you know, like tiny blood suckers. Bloodbugs? Bloodbugs. Yeah. Should we mount a campaign with our listeners? I think so. Listeners, if you have a better name for the bedbug, we want to hear it. Call us 8774 SciFRI. 8774 SciFri. Tell us your new name for bedbugs and how you arrived at it. Lindsay, thanks for taking us on this trip down bedbug lane. Yeah, it's been an absolute pleasure.

Dr. Lindsay Miles entomologist at Virginia Tech in Blacksburg, Virginia. And if you need a pallet cleanser from talking about bedbugs, may we interest you in some pretty pictures of butterflies? Read our story about how scientists studied a cross-continental butterfly migration and the photographer who snapped photos along the way. Visit science friday.com slash butterfly photo to check it out. We have to take a quick break, and when we come back, if bedbugs give you the ick, we have a surprise for you, ancient wasps that caught prey with their butts.

The further back we go in time, the more weird insect life becomes. And the further we have to look for modern. parallels. In this case, we had to go outside the animal kingdom. Don't go away. Entomologists report a new fossil find, a prehistoric wasp that had a one-of-a-kind attack method. It seemed to grab its prey with its butt flaps, capturing its booty in its booty, kind of like a tookus flytrap. And then once the wasp had its bray and tail, it injected its parasitic eggs into it, which would then hatch and slowly devour the victim from the inside out. Here to tell us more is Lars Willemson, curator at the Natural History Museum of Denmark in Copenhagen.

Welcome to Science Friday, Lars. Thank you very much. Give us a character sketch of this wasp. When did it live? Yeah, I mean, it's a 100 million-year-old wasp from the Cretaceous at the same time as we had dinosaurs still living on the earth. It's well preserved in amber. from what is known as Myanmar Amber. Myanmar Amber.

Yeah. So it was probably living in a forest area. And in fact, we found 16 specimens of this very particular wasp. So we were able to study its anatomy in greater detail than we would normally be able to. Would you agree with my assessment that it captured prey in its butt flaps? That's what we write in the paper. So that's how we imagine that this could have happened. I'm certain you didn't use the term butt flaps in the paper.

No, we're talking about abdominal flaps, sixth and the seventh segment of the abdomen of the wasp. And how do they seem to work? Are they triggered mechanically? Like, how do they actually trap a victim? Yeah, I mean, we imagine that this wasp was, I mean, it doesn't seem to have been able to move very fast. The legs are not very long. And so we imagine it would probably wait like an ambush with the trap open. And on the edge of the lower flap of the trap, there's some very elongate hairs extending fan-like. And we imagine these served as trigger hairs.

And this is how a Venus fly trap works, right? The trigger hairs. Yeah, yeah, more or less. I mean, a Venus fly trap, the trigger hairs sits inside the flaps. So the fly or whatever the plant has to catch has to move all the way in between the leaves. that might not have been necessary for the host of this wasp. So when a potential victim or host moved just behind the abdomen of the wasp, the wasp would sense it and then quickly lunge backwards and grasp the host in the flaps. You wrote in the paper that this apparatus is unlike anything previously reported in any insect known to us. I mean, none of us have seen anything like it before.

I mean, at first, when we saw this, we saw it must be some kind of artifact, some kind of deformation of the specimen, which is not uncommon. Oh, like, you didn't even think it was real? No, not at first glance. And as far as we know, I mean, you can never know for certain what an extinct organism lived like. I mean, how it used its anatomal features to go around its daily life. So what you do, you compare with organisms living today. And the further back we go in time, the more weird insect life becomes.

And the further we have to look for modern parallels. In this case, we had to go outside the animal kingdom to find something that we thought resembled what we were looking at. Do you think that insects get overlooked? I mean, if you found a dinosaur that used its butt to capture prey, I feel like it would be headline news. Yeah, for sure. And this is, I mean, it's very unusual for me to have a paper getting so much attention

that this has never happened to me before. So I certainly feel that insects are overlooked in general. But, I mean, they basically invented everything that humans could think of, and usually millions of years before humans. I mean, they have invented agriculture. You have leaf cutter ants doing that. and yeah, I mean, almost everything you could think of. What's this wasps name, so we know what to call it in our nightmares?

Yeah, it's Sirenobetilus Caruptis. This is a fancy name, of course. I mean, Caruptis refers to a monster in ancient Greek mythology, which almost swallowed Odysseus when he was traveling the world. Yeah, Sirenubedelous, I mean, a siren was also a monster that lured sailors to their deaths. But it's also because there's a group of mammals, sea cows, manatees, and the tail of a manatee in outline actually looks like the flap of this wasp also. So that was another reason to name this species like this.

I love it. Thank you, Lars. You're welcome, thank you. Lars Willemson, curator at the Natural History Museum of Denmark in Copenhagen. Thanks for listening. Don't forget to rate and review us wherever you listen, but only if you like the show. It really does help us get the word out and get the show in front of new listeners. Today's episode was produced by Shoshana Bucksbaum.

I'm Flora Lichtman. Thanks for listening.