How Insects Changed The World—And Human Cultures

SOPHIE BUSHWICK: This is Science Friday. I’m Sophie Bushwick.

Did you know there are 10 quintillion individual insects on the planet? That is a 10 with 18 zeros after it. Which means that for each and every one of you, dear listeners, there are 1.25 billion insects hopping, buzzing, and flying around. And this incredible menagerie of insects has fundamentally changed the world. Think honey bees, silk moths, fruit flies. And, for better or worse, we can’t forget critters like mosquitoes and fleas.

The Insect Epiphany: How Our Six Legged Allies Shape Human Culture, is a new book that examines the many ways the insect world has changed our own, from fashion to food, to engineering and beyond. Joining me is entomologist and author Dr. Barrett Klein. Welcome to Science Friday.

BARRETT KLEIN: I am thrilled to be with you on Science Friday.

SOPHIE BUSHWICK: How far back in time does the relationship between humans and insects go? Do we know that?

BARRETT KLEIN: 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 katydid, on a sliver of bone found in the Cave of Alain, in France.

And then later, maybe 7,500 years ago, you can see the remnants of a painter’s ocher pigment on a cave in eastern Spain, depicting a robbery of a honeybee colony from a cliff face.

SOPHIE BUSHWICK: Wow.

BARRETT KLEIN: Well, the very oldest, complete and decipherable sentence ever found in an alphabetic script pertains to insects.

SOPHIE BUSHWICK: OK, so what does it say? I have to know.

BARRETT KLEIN: One of the archaeologists, 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.”

SOPHIE BUSHWICK: [LAUGHS]

BARRETT KLEIN: 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.

SOPHIE BUSHWICK: 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.

BARRETT KLEIN: Yes, indeed. In fact, some of your listeners may be imbibing a beverage, consuming a food, or taking 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 considered them worms or berries, or worm berries. 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.

SOPHIE BUSHWICK: Wow, the perfect red. So there really are insects everywhere for those with the eyes to see.

BARRETT KLEIN: That’s right. So another scale insect, the lac insect, is harvested by millions of people in India and Thailand, and, if processed properly, creates this coating. So imagine 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 phloem, 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 on your body, that shiny apple, that shiny piece of candy, that 78 RPM record, may all be derived from the secretions of lac insects.

SOPHIE BUSHWICK: Wow. So if you had to pick just one, what singular insect do you think changed our world the most?

BARRETT KLEIN: Yow! Well, I mean, we have over 180,000 known species of moths and butterflies, all of whom spin silk to form cocoons, for example, in which they can pupate. But one, for 5,000 years, has been domesticated to such an extent they no longer fly of their own volition. They utterly rely on humans. And that’s the Bombyx 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.

SOPHIE BUSHWICK: 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.

BARRETT KLEIN: Yes. So silk, thanks to Bombyx mori, they form cocoons as larvae within which they pupate. Well, picture one of these cocoons plummeting from a mulberry tree into a hot cup of tea. The tea belongs to an empress. And this is Leizu. So we’re talking 5,000 years ago, legend has it, Leizu witnessed this cocoon dropping in her steaming hot cup of tea. And the Saracen adhesive that holds the fibers together starts to melt. The lustrous fiber unravels. And Leizu has a lady in waiting grab one end and walk and walk and walk, say, a mile away, and the single thread exposes or reveals the potential that Leizu– again, according to legend– conceives as being a new textile, and then imagining, as an entrepreneur, sericulture, the business of producing silk from the domesticated silkworm moth.

SOPHIE BUSHWICK: 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?

BARRETT KLEIN: 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.

SOPHIE BUSHWICK: 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 bio-mimicked group of critters out there, huh?

BARRETT KLEIN: 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.

SOPHIE BUSHWICK: I really enjoyed the story about the CIA’s Insectothopter.

BARRETT KLEIN: Oh, yes, that’s a winner. So here you have the US 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 aficionado on the team. He said, how about Anax 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 cross wind through the whole project off kilter.

SOPHIE BUSHWICK: Oh, no. [LAUGHS]

BARRETT KLEIN: But it did fly for 60 seconds and 200 meters.

SOPHIE BUSHWICK: All right, so not entirely a failure. But you also wrote about biomimicry in medicine like with vaccines. So how do we look to insects to make better vaccines?

BARRETT KLEIN: A lot of ways. So we can look to venom, surprisingly, to aid us biomedically. For example, bee venom therapy has been used for arthritis, arthralgia, Parkinson’s, maybe ALS, multiple sclerosis, and other conditions. Poisonous proteins from caterpillars and Cantharid beetles have anticancer 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 armyworm caterpillar.

SOPHIE BUSHWICK: 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.

BARRETT KLEIN: Well, when I lived in New York City, I did study mantis-style kung fu 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 [IMITATES A CICADA DRONING] 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 him. So learning the movements of the upper body of a mantis compelled Wong Long to learn this art until he defeated his brother, monk Feng, upon his return.

So I’ve studied mantis-style kung fu, 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.

SOPHIE BUSHWICK: 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?

BARRETT KLEIN: 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 also see all of the explicit, as well as the hidden ways, that insects affect our cultures start to dwindle, vanish, crumble, or change irreparably.

SOPHIE BUSHWICK: How is this relationship with insects going to be part of our collective legacy when humans are long gone?

BARRETT KLEIN: 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 of 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 Waspman or all manner of insect music or reports about how insects have affected human culture.

SOPHIE BUSHWICK: Barrett, Thank you so much for sharing this bug joy with us.

BARRETT KLEIN: Wow, thank you so much for having me. The opportunity to think about how we as a collective can think more 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.

SOPHIE BUSHWICK: Dr. Barrett Klein is an entomologist and the author of The Insect Epiphany, based in La Crosse, Wisconsin.

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