Science Friday - How Insects Changed The World—And Human Cultures

Episode Date: October 30, 2024

Did you know that there are ten quintillion—or 10,000,000,000,000,000,000—individual insects on the planet? That means that for each and every one of us humans, there are 1.25 billion insects hopping, buzzing, and flying about.A new book called The Insect Epiphany: How Our Six-Legged Allies Shape Human Culture celebrates the diversity of the insect world, as well as the many ways it has changed ours—from fashion to food to engineering.Guest host Sophie Bushwick talks with entomologist and author Dr. Barrett Klein about the beauty of the insect world, how it has shaped human history, and what we can learn from these six-legged critters.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Insects are all around you, and sometimes they're closer than you think. Some of your listeners may be imbibing a beverage, consuming a food, or kicking on some cosmetics that feature the dried-up, pulverized bodies of cochineal bugs. It's Wednesday, October 30th, and you're listening to Science Friday. I'm sci-fri-producer Rasha Iridi. Did you know that there are 10 quintillion individual insects on the planet? That's a 10 with 18 zeros after it. That means that for each and every one of you, dear listeners, there are 1.25 billion insects hopping, buzzing, and flying around.

And that incredible menagerie of insects has fundamentally changed the world. Think honeybees, silk moths, fruit flies. And for better or worse, critters like mosquitoes and fleas. Here's guest host Sophie Bushwick with more. Joining me is entomologist and author, Dr. Barrett Klein. Welcome to Science Friday. I am thrilled to be with you on Science Friday. How far back in time does the relationship between humans and insects go?

Do we know that? Well, it most certainly precedes Homo sapiens. So when we hit the scene, insects were already on the scene. for 400 plus million years. So being surrounded by insects, we had a source of sustenance, food. We heard the first musicians and were surrounded by insects

that we could use in all manner of ways. So some of the hints of these connections came way later. So for example, you can look at the oldest depiction known of an insect by a human artist is the inscription of a cave cricket or a Katie did on a sliver of bone found in the cave of Anlen in France.

And then later, maybe seven and a half thousand years ago, you can see the remnants of a painter's ochre pigment on a cave in eastern Spain depicting a robbery of a honeybee colony from a cliff face. Wow. Well, the very oldest, completely. pleat and decipherable sentence ever found in an alphabetic script pertains to insects. Okay, so what does it say? I have to know. One of the archaeologist Yosef Garfinkel helped to uncover this and translate it.

You have 17 letters, forming seven words, and this transports us to the age of the Canaanites. And this is what the sentence said. May this tusk root out the lice of the hair and the beard. Sure enough, those letters were just on a louse comb, a fine-toothed comb that tells us how ancient, deep, and conflicted our relationship with insects has been. Oh, my gosh. I mean, in reading your book, I'm seeing insects everywhere now. They're in food, they're in fashion, even in just the color red.

Tell me about where that started. Yes, indeed. In fact, some of your listeners may be imbibing a beverage, consuming a food, or kicking on some cosmetics that feature the dried up, pulverized bodies of cochineal bugs. These are scale bugs that thousands of years ago were harvested, domesticated by Aztec and Maya people. Now these scale insects don't look much like insects at all. Some consider them worms or berries or wormberries. Well, the conquistadors exported by the ton these scale bugs to the old world. Second only to exports of silver, this valuable resource changed the way we viewed, well,

everything, color. So artists, textile manufacturers, and nobility took advantage of this, what Amy Butler Greenfield, called the perfect red. So nobility, clergy, and others would take advantage of this source of red. Wow, the perfect red. So there really are insects everywhere for those with the eyes to see. That's right. So another scale insect, the lack insect, is a lot of insect, is harvested by millions of people in India and Thailand, and if processed properly, creates this coating. So mention this.

You've got a true bug that protects itself underneath this little armored excretion or secretion from her own body in order to safely feed on the plant's floam or sugary solution. Well, an enterprising human comes along, finds this hard substance, liquefies it, processes it, and we can create our own protective layer over everything. So wood furniture, floors, plaster, electronics, cosmetics, cosmetics on your body, that shiny apple, that shiny piece of candy, that 78 RPM record may all be derived from the secretions of lack insects. Wow. So if you had to pick just one, singular insect do you think changed our world the most?

Yow! Well, I mean, we have over 180,000 known species of moths and butterflies, all of whom spins silk to form cocoons, for example, in which they can pupate. But one, for five thousand years, has been domesticated to such an extent they no longer fly of their own volition. They utterly rely on humans, and that's Bombix Mori. That paved the path for the Silk Road. For hundreds of years, much of the world was connected for commerce, and that meant material goods being transported, but also language, ideas, religions, and disease, as well as genes. So the silkworm moth is probably one of the top contenders for most radically impacting human history. One thing that you mentioned in the story of the silkworm insect is this story about a teacup.

And I was wondering if you could tell it to us now. Yes. So silk, thanks to Bombix Mori, they form cocoons as larvae within which they pupate. Well, picture one of these cocoons plummeting from a bulberry tree into a high. hot cup of tea, the tea belongs to an empress. And this is Leszhou. So we're talking 5,000 years ago. Legend has it. Lezhu witnessed this cocoon dropping or steaming hot cup of tea. And the saracen, the adhesive that holds the fibers together starts to melt. The lustrous fiber unravels. And Leszou has a lady in waiting, grab one end.

and walk and walk and walk, say a mile away in this single thread, exposes or reveals the potential that lays you, again, according to legend, conceives as being a new textile. And then imagining, as an entrepreneur, Sarah Culture, the business of producing silk from the domesticated silkworm moth. More insect joy is coming. Coming up right after the break. Let's switch gears a little bit and talk about a bug that doesn't get the recognition.

It really deserves the dung beetle. Can you tell us about the Australian dung beetle project and what it taught us about the importance of these insects? That's right. So if we look at the marsupials in Australia, they produce pretty dry, small excreta, dung. But when from England, cattle were first brought to Australia, you had voluminous, moist, massive amounts of dung that the native dung beetles of Australia simply couldn't deal with. And dung beetles work on as decomposers dung in a lot of different ways. They'll roll balls away most famously. Well, here, you didn't have the beetles who could cope with that dung.

So this project, many years later, imported exotic dung beetles that were used to dealing with cattle by great number. And then gradually, the smelly fields of domesticated cattle and in the wilds started to clear up. Wow. I also find biomimicry really fascinating. Basically, when we're looking towards nature to inspire design, And it seems like insects might be the most biomimicked group of critters out there, huh? Absolutely. And I had a fun time looking deeply into story after story after story, whether it be biomedical research, architecture, art, robotics, to see how from head to tarsus insects have solved engineering and other problems.

I've really enjoyed the story about the, the CIA's insectothopter? Ah, yes, that's a winner. So here you have the U.S. Central Intelligence Agency in the 1970s with their top secret operation to create a micro-aerial robot that could service them for espionage. So how do you sneak up on two people in a secret conversation? Well, send in an insect. And originally they thought bumblebee, but bumblebees fly really erratically, and there was

an amateur dragonfly officinado on the team. He said, how about Aenex Junius, this large green darner dragonfly? So they built a robot, a robot that could fly thanks to a gas-operated motor in the thorax that would run through the body and glass beads for eyes that would be deformed given voices,

and then lasers that would guide that dragonfly and bounce off those beaded, glass eyes in order to recreate the conversation. Sadly, a slight crosswind through the whole project off kilter. Oh, no. But it did fly for 60 seconds and 200 meters. All right. So not entirely a failure. But you also wrote about biomimicry and medicine, like with vaccines. So how do we look to insects to make better vaccines? A lot of ways. So we can look to venom, surprise. to aid us biometically. For example, B-Venem therapy has been used for arthritis, arthritis,

arthritis, arthralgia, Parkinson's, maybe ALS, multiple sclerosis, and other conditions. Poisonous proteins from caterpillars and cantherid beetles have anti-cancer properties. And even in the case of a vaccination for COVID-19, if you're allergic to one of the ingredients in the most popular vaccines, you could rely on Novavax, a vaccine that instead included an ingredient, proteins developed from a moth, army worm caterpillar. Your book also has this chapter called Act Like an Insect. So I want to know what's one way that you are trying to behave more like an insect.

Well, when I lived in New York City, I did study Mantis-style kung-fou for a while. That was a winner. So picture Wong Long, long ago studying Shaolin Kung Fu and being defeated over and over and over again by his brother Feng. Until studying on his own Confucian texts heard a cicada nearby, grabbed by, the speed and power of a mantis. This inspired him. So he took the mantis home, stuck a piece of straw right in the mantis's mug, and saw how the mantis would use raptorial forelegs to evasively maneuver or grab whatever object was presented to. So learning the movements of the upper body of a mantis compelled Wang Lung to learn this art until he defeated his brother, monk,

Feng upon his return. So I've studied mantis-style kung-fou, but I've been most impressed by dances, theater performances, fashion, and music that all incorporate insects in different ways. And as I traveled through the different stories, I found surprise after surprise after surprise. As we've talked about, insects have fundamentally changed how we exist in the world. But at the same time, insect populations are crashing right now. How do we reckon with that? That's right. All evidence suggests that anthropogenic change, human-induced catastrophes from global climate crisis, habitat destruction, pollution that can be light pollution, chemical pollution, invasive species spread, all of these factors and more exacerbated by humans have caused

major declines in arthropods, those segmented, jointed, -legged animals that are so diverse on the planet, and most of whom are insects. So with 1.1 million described species and so many more, maybe magnitudes more, undescribed species, we're experiencing losses like never before. We're in a major mass extinction of our own making, and we are experiencing some of the consequences of that. So not only do we experience ecosystem services faltering with insect declines, but we'll see all of the explicit as well as the hidden ways that insects affect our cultures start to dwindle, vanish, crumble, or change irreparably. How is this relationship with insects

going to be part of our collective legacy when humans are long gone? We have a choice as to what legacy we can leave. We can leave a legacy of destruction, exacerbating diversity declines and the loss of not only insects, but all those organisms, including humans, who depend on insects, we can contribute to the loss of our cultural assets thanks to insects, or we can shift gears. For example, we've sent two physical objects that have escaped the heliosphere, the pull of the sun, two Voyager spacecraft, and we still have contact with one of them.

And marvelously, one carries an image of an insect and a recording of a cricket. If those are ever intercepted, those cultural associations will come with them. We've sent out electromagnetic radiation that flies through interstellar space. If ever intercepted, you can hear who's wasp man or all manner of insect music or reports about how insects have affected human culture. Barrett, thank you so much for sharing this bug joy with us. Wow, thank you so much for having me.

The opportunity to think about how we as a collective can think more positive. positively about our associations and celebrate the miniature marvels all around us. I just implore your listeners to take time to appreciate our biodiversity on the only living planet we know. Dr. Barrett Klein is an entomologist and the author of The Insect Epiphany, based in La Crosse, Wisconsin. And that's it for today's show. Lots of folks help make it happen, including Emma Gomez.

Sandy Roberts. Robin Casmer. Beth Rami. Join us tomorrow for a Halloween offering to discuss vampires and paribiosis, a spooky procedure that taps into young blood. I'm SciFri producer, Rasha Aridi. Catch you then.