TERRY GROSS, host:
This is FRESH AIR. I'm Terry Gross.
Our guest, Amy Stewart, wrote a bestselling book a couple of years ago called "Wicked Plants," about strange and dangerous inhabitants of the botanical world. For her new book, "Wicked Bugs," Stewart has moved from flora to fauna, detailing more than 100 species that creep, crawl, fly, sting, bite, infect, invade and annoy us in ways that will fascinate and sometimes nauseate you.
Stewart writes that she knows that most of the 10 quintillion insects alive today aren't harmful and do many helpful things, like pollinating plants and controlling pests. This book, she says, is about the dark side of the relationship between bugs and humans and about how bugs sometimes abuse one another.
A word of warning: Some of the descriptions ahead might trigger your gag reflex.
Amy Stewart has written four previous books on horticulture and the natural world. She lives in Eureka, California, where she and her husband own an antiquarian bookstore. She spoke with FRESH AIR contributor Dave Davies.
DAVE DAVIES, host:
Well, Amy Stewart, welcome to FRESH AIR. I read your book, and I'm all itchy.
(Soundbite of laughter)
DAVIES: Start us out with a good one here. Tell us about the Asian giant hornet.
Ms. AMY STEWART (Author, "Wicked Bugs"): Yes, a large and fearful hornet that we don't have to worry about too much, but if you were in Tokyo right now, you might want to start keeping your eye out for.
It's - it injects a deadly neurotoxin. It actually can be fatal. They actually call it - in Asia, they call it a yak-killer because it has such a potent neurotoxin.
But the interesting thing about the Asian giant hornet is not just that it's frightening for people but the way it goes after honeybees.
DAVIES: And how big is it?
Ms. STEWART: Well, you know, this thing, they call it a sparrow wasp because it's about five centimeters or so. So it actually can look like a little, tiny flying bird.
DAVIES: And what does it do to bees?
Ms. STEWART: Well, what it does to be is it goes after their colonies. It kills them, and it steals their honey. So this is actually a very aggressive, murderous, giant wasp.
And the honeybees have developed this interesting way to fight back, which is that they can lure one of these giant wasps into their hive and sort of snuggle up next to them and fly at such a fast pace right around them, just sort of hover around them and tremble right around them such that they raise the temperature to exactly 116 degrees, which is just hot enough to kill the wasp without quite being hot enough to kill the honeybees.
So it's this totally bizarre insect defense with body heat that's otherwise unknown in the insect world.
DAVIES: And when the Asian giant hornets kill the bees, I mean, how do they go about that work?
Ms. STEWART: Well, usually they send out a scout first, and the scout will look for a good hive and might grab a honeybee or two and take it back to feed it to its young. And if it looks like a good one, they'll mark it with a pheromone, and then a swarm of them will come and attack.
And they really do, like, tear through the hive, ripping the heads off of honeybees and tossing their bodies around and robbing the honey. And the bee larvae and taking them back to feed their own children. I mean, it really is this brutal massacre of honeybees.
DAVIES: And the other fascinating thing about this creature is that it's - some extract of it is actually a performance-enhancing drug?
Ms. STEWART: Yeah, this is the strange thing about these giant hornets is that they don't actually eat much themselves. So they fly around a lot looking for food for their young. They feed dead insects to their children. But they don't actually eat much.
So the way they actually get their food is that after they have fed their young, they bend over, and they sort of tap on their children, and their children open their mouths and offer up this little drop of clear liquid that's filled with amino acids and gives the parents energy to go on and do what they do.
So it turns out that these amino acids are considered a performance-enhancing drug and that Olympic athletes have actually used it. It's a natural substance. So it's allowed to be used. And there's actually a sports drink that mimics the amino acid component of these giant hornets.
DAVIES: Wow. A lot of people have talked about bedbugs. Early in the book, you introduce us to bat bugs. What are they?
Ms. STEWART: Yes. The African bat bug is a very close relative of the bedbug that we have all come to fear in this country. The bat bug would rather feed on bats if it can.
So the way people run across bat bugs is if you were to have bats nesting in the rafters of your house, maybe up in your attic, which happens, the bat bug will sort of live in the rafters and just feed on the bats every now and then. They only need to really eat once a year. So they're not - you know, they're just on the bats occasionally.
But if the bats go, let's say you close up any gaps in your house so that bats can no longer get in, then bat bugs will wander around the house and find you eventually. They are going to find something to eat.
I mean, the interesting thing about bat bugs, too, is that they have this violent, weird mating method. So even though I was trying not to be too hard on bugs for what they do to one another, I was rather appalled with the ways in which bat bugs mate.
DAVIES: Yeah, well, explain that.
(Soundbite of laughter)
Ms. STEWART: So what happens is that the males don't bother looking for any particular, let's say, access point in the female's body. They sort of just stab their way into the female's gut any place they can find to inject sperm.
And as you can imagine, the females don't like this very much. And it's actually very hard on the females. And when you have colonies of bat bugs that are isolated in a laboratory, so the females can't get away, it kills them eventually. It's a very violent mating ritual.
So eventually the females developed this little false organ to accept the sperm so that there would be some way for the sperm to get in without just them being jabbed anywhere in their body.
And that kind of worked, but then what scientists discovered is that male bat bugs will actually go after other male bat bugs, as well. So the males developed a similar and even better false organ to receive the sperm, which would of course be useless to them, so that they could also avoid being stabbed anywhere in their body by their fellow male bat bugs.
And then the females, seeing that the males developed an even better version of this little false organ, improved theirs, too. So there's all these strange gender-bending changes going on in the bat bug world, as it turns out. And I don't think it's over yet.
DAVIES: Let's talk about worms a little.
(Soundbite of laughter)
DAVIES: The pork tapeworm, tell us about that, how it gets into the human intestine and the course it takes there.
Ms. STEWART: Oh, I'm so glad you asked me about the pork tapeworm. I'm totally - I am totally fascinated with this, and no one wants to talk about tapeworms with me. So I can't believe you actually want to hear this story. It's an amazing...
DAVIES: Oh, I'm here, yeah.
(Soundbite of laughter)
Ms. STEWART: It's an amazing story. So here's how pork tapeworm infestations work is that if a pig is infested with these tapeworms, they will have little cysts inside of them that contain the larvae of the tapeworms. So those are inside the pig's body.
And the way that they get into humans is if humans eat pork from pigs that are infested with the tapeworms, and that meat has not been cooked properly. So that would be its route into humans.
Now, the weird thing is that pork tapeworms have to get into the body of a human in order to develop into the next stage of its life cycle. No other animal works. We are what is called the obligate host of the pork tapeworm.
So once it gets into the human body, it kind of settles into the stomach. It grows to adulthood. It finds another adult tapeworm and falls in love, and they have a lot of babies. And the adults can live in the body for, you know, 10, 20 years.
And then the eggs - shall we say that the eggs leave people's bodies the way that most things leave our bodies...
Ms. STEWART: ...and that adult tapeworms will eventually leave on their own or die.
So, but here's the weird thing. So you can say: Okay, well, I don't really have to worry about pork tapeworms because I don't eat badly cooked pork, and, you know, pork in this country is - you know, our pigs are healthy and so on and so forth.
But here's the thing: A person who is infected with tapeworms can spread those eggs to other people directly, without having to bother with involving a pig in the process. So this is why it's so important that we wash our hands when we go to the bathroom.
These little eggs can - if someone handles food, they can get in food. And when you swallow one of those eggs, instead of getting the larvae from the pig, if you actually get an egg in you, then that little creature hatches and behaves very differently.
It doesn't just settle down in your stomach and start laying eggs. It travels all over your body. It sort of feels free to explore. It might get in your lungs. It might get up into your brain. It might go sort of anywhere.
So you actually have cases of people being diagnosed with brain tumors only to find out what they actually have is a tapeworm living in their brain. And what really astonished me is that tapeworms in the brain are the leading cause of epilepsy worldwide.
DAVIES: Really? Wow.
Ms. STEWART: Yeah.
DAVIES: Can people sense a tapeworm in their intestine?
Ms. STEWART: It does not appear so. I mean, pork tapeworms are actually pretty widespread in places in the world where a lot of pork is eaten, and while it might cause some digestive problems, a lot of people don't know that they have them.
DAVIES: Our guest is Amy Stewart. Her book is "Wicked Bugs." We'll talk more after a break. This is FRESH AIR.
(Soundbite of music)
DAVIES: If you're just joining us, our guest is writer Amy Stewart. She has written a new book about scary, creepy, crawly things called "Wicked Bugs."
You have a chapter about zombie bugs and some of the ways that they use and abuse other species. Let's talk about the emerald cockroach wasp. This isn't a cockroach, this is a wasp, a jewel wasp, right, but it has a special relationship with a certain kind of cockroach, right? Explain this.
Ms. STEWART: Yes. This is a wasp that likes to actually lay her eggs inside a particular species of cockroach. So what she does is she goes and finds herself a good cockroach, and she stings it, and the sting kind of paralyzes it for a minute. And she's able to get her stinger right into the brain of the roach and inject a sting into the part of the cockroach's brain that actually sort of disables it from any instincts to run away.
So it makes it this very docile, obedient cockroach, if you can believe this. And so then the roach pretty much does her bidding, and she's able to grab it. They have even been seen grabbing on to the antennae of a cockroach and leading it around the way you'd lead a dog around on a leash.
And she can lead the cockroach around, park the roach wherever she wants it to be, lay her eggs on the roach's belly, and it will just sit around and wait for the eggs to hatch, and the larvae eat the roach. I mean, that's the whole point of laying the eggs there.
And it very patiently puts up with that and basically allows itself to be devoured. And it ends up becoming a protective cocoon for the larvae as they're getting ready to emerge into adulthood.
DAVIES: Yeah, well, I guess some would consider that a fitting fate for cockroaches.
Ms. STEWART: Right, yes, we all hate cockroaches.
DAVIES: But I'm fascinated that somebody somewhere has studied this wasp and has actually observed it stinging the cockroach's brain in exactly the right spot and then leading it around by this little antennae leash. This has all been observed and studied.
Ms. STEWART: You know, you bring up a good point. Entomologists are my favorite people in the world. For every bug, there is an entomologist somewhere who is more than happy to tell you about the lifetime of research they've devoted to that particular little insect.
I had such a good time tracking down people who have spent their whole lives specializing in and studying these insects. I found two different entomologists who study the insects of the Civil War, the insects that affected Civil War soldiers.
And one of them is in fact himself a Civil War re-enactor, and he carries around live examples of the kinds of bugs that would have lived on the soldiers and lived in their food, as well. There were weevils in the hard tack. I mean, bugs were a big part of the Civil War, and it's just fascinating to me that someone has decided to make that their life. I love these people.
DAVIES: So someone is carrying weevils for their hard tack biscuits for a re-enactment?
Ms. STEWART: Carrying weevils around but not just weevils, also lice and bedbugs and all the other critters that actually inhabited the soldiers themselves and not just their food.
DAVIES: Oh, boy. One more of these zombie creatures: the green-banded broodsac. Do I have this right?
Ms. STEWART: The green-banded broodsac. So what I love about the green-banded broodsac is how highly improbable a lifecycle like this actually is.
So this is a tiny, little flatworm that begins its life in the gut of a bird. So the little eggs are excreted through bird droppings. They land on the ground, and in order for them to move into the next stage of their life, those little eggs have to get inside the body of a snail.
So those bird droppings sit there, and if a snail comes along and eats them, then the little eggs can hatch, and they can grow into the next stage of their life.
But then, in order for them to reach adulthood and mate and start the next generation, they have to get back inside a bird. So they actually push their way through the snail's tentacles and force the tentacles to wave around in the open air, which is something that no snail in its right mind would ever do.
So they're sort of waving around like: Hey, bird, come get me. You know, and the snail's like: No, no, don't do that. And so a bird spots them, sweeps down, eats the snail, thereby swallowing these little larvae, which will grow into adults and mate and lay eggs and start the cycle all over again.
Ms. STEWART: I mean, who thought of that? Like, what are the chances? It just seems so highly improbable, these intricate lifecycles that require you to move from one to the next to the next to the next in order to survive. I mean, youve got to give it to these bugs.
DAVIES: Yeah, well, they've been around for, what, a billion years or more?
Ms. STEWART: They've been around forever, and they are so tenacious, and they manage to keep going in spite of our best efforts to get rid of them.
DAVIES: You write some about spiders, including the black widow, not as deadly as people think, right?
Ms. STEWART: Yeah, there's not actually much mention in the news of people getting bitten by a black widow or being harmed by a black widow until the 20th century.
But the fact is that black widows don't want to bite you. It's painful. People, their - people's nervous system will sort of, you know, go on the alert, and a flood of pain will course through your body, and you can get kind of dizzy. You can get some - you know, your heart will race.
It's not fun, but there are really no reports of people being killed by black widows. And brown recluse, same thing. You know, people love to hate the brown recluse, and everyone insists that they have them, even where they don't.
You know, I live in California, and everyone is convinced they've seen a brown recluse, and entomologists in California are so frustrated by this that some of them actually got together and started a show-me-the-spider challenge and offered a cash reward to anyone who could send them a brown recluse that they had captured in California. And no one could.
They don't exist there, and yet we cling to this notion that they are out there in our backyards and that they are out to get us, when in fact, you know, they're really not.
DAVIES: Bugs have been used as weapons of war at times, right? Tell us some examples of those.
Ms. STEWART: They have, yeah. I was really surprised by this. They have been used in a lot of really interesting ways. So there are ancient examples of bugs being used as war, you know, like the Greeks or the Romans filling up a hive with angry hornets or with scorpions and lobbing it at their enemies.
But there have actually been some more recent and really more terrifying uses of bugs in a war. And I think the most disturbing one was in World War II. There were some experiments done by the Japanese with fleas infested with the plague.
And their plan was to take clay bombs filled with plague-infested fleas and drop them into enemy territory. And this is something they actually did.
They tried it out on the Chinese. They dropped some into China, and, in fact, instances of the plague were found. I mean, it worked. And they had a plan to do it in California. It was called - the operation was called Cherry Blossoms at Night, and the plan was to drop these clay bombs filled with plague-infested fleas over California. The war came to an end before that could happen.
But, you know, that's recent. And there's even actually, there's even a project going on right now. So the Pentagon is working on a project where they would like to embed computer chips into butterfly larvae and let those caterpillars hatch into adults and with the hope that they can remotely control the flight path of a butterfly using a little computer chip. So they could fly a butterfly into enemy territory and do a little surveillance that way.
(Soundbite of laughter)
Ms. STEWART: Isn't that astonishing?
DAVIES: Now, you wrote the book "Wicked Plants," and I've read that you still have a garden with some poison plants in it. Is that right?
Ms. STEWART: I do. You know, it's tough for me to write about plants that I've never seen. And I really wanted to grow these plants if I could. Some of them are really hard to get. So for instance, mandrake is not a plant that you can just walk into a garden center and order up.
So if I found somebody, if I found some plant collector, some person off the beaten path that happened to have any of these really poisonous, deadly, strange plants, I wanted them.
So - and once I started collecting them, they couldn't live forever under grow lights in my office. They really had to go outside. So I have a little section in my garden that's gated off. I have chickens in the backyard, and they free range. So, you know, the chickens couldn't get in. It was protected from the neighbors who might be wandering past in the front.
And I planted about 35 or 40 species of poisonous plants in this garden. And I decided to go ahead and make it a really creepy garden. Instead of having plant markers, I actually made tombstones, little cement tombstones that had not the name of the plant but what the plant did.
So there's all these tombstones that say things like kidney failure and madness and asphyxiation and chemical warfare. And there's bones buried around the garden and all kinds of, you know, all kinds of creepy, scary elements. So it was a very fun garden to do, and it's one that's actually been imitated.
There are some botanical gardens who have sort of taken that idea and run with it. So now everybody's doing it.
DAVIES: Well, Amy Stewart, it's been really creepy. Thank you.
(Soundbite of laughter)
Ms. STEWART: My pleasure.
GROSS: Amy Stewart is the author of "Wicked Bugs." She spoke with FRESH AIR contributor Dave Davies. You can read an excerpt from "Wicked Bugs" and see pictures of many of the bugs mentioned in the interview on our website, freshair.npr.org.
I'm Terry Gross, and this is FRESH AIR.