Short Wave - Plot twist: We're probably way undercounting insects on Earth

Episode Date: July 10, 2026

Maybe you’ve wondered about it late at night as a mosquito buzzes in your ear. Or when you kick over a rock and watch dozens of little critters crawl away: How many types of insects are there in the world? Scientists have been interested in answering this question for years. A new study — based on a census of tiny and, frankly terrifying, parasitoid wasps — suggests there’s way more than previously thought. Like, millions more that are just waiting to be discovered.  Interested in more bug science in the news? Email us your question at [e-mail] public media with NPR+ and enjoy perks for over 25 podcasts like this one. It includes perks like bonus episodes, early access, archive access, curated playlists and sponsor-free listening. Learn more at plus.npr.org. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, short waver, is Regina Barber here. And Nate Rutt. With our biweekly science news roundup featuring fellow space nerd, Scott Detrow, of all things considered. Hey, Scott. I am slumming it here today talking in an episode that contains non-space news, but I'm doing that for you. Excellent. We're going to talk more about space next week, too.

But this week, we've got a few mysteries unraveling. First up, how much? How many different types of insects are there on the planet? Scott, do you have a guess? Like, overall raw total or like species? Species. Okay, I don't know. Four million?

I don't know. I don't know, a lot. Well, you didn't go over. I'll give you that. We're going to tell you. Quick side question, just because I'm a nerd. Do either of you guys have a favorite insect? Yes.

What's yours? It's a firefly because I never saw them on the West Coast until I moved to the East Coast. I like that. I was going to say firefly. Oh, we're the same. We're the same. Let's get firefly tattoos. I was literally looking up during the 4th of July, and I was looking at all the stars.

We were out away from city lights, and I saw the stars, and I saw fireflies in the trees. It was so cool. What a win. I know. Speaking of astronomy, you know, see, that was my segue. We have another story that looks at quasars, bright lights from ancient galaxies. So these are really, really old fireflies that can tell us more about the formation of the universe. Yeah, and the final study looks at the...

Let's say unfortunate eating hats of California wolves. You are listening to Shortwave, the science podcast from NPR. All right, Regina and Scott. We've got a lot to get into. Let's start with the insects. We've established there are a lot of insects. And I guess, like, I'm wondering, how do you even go about counting them? So this study starts in a protected area in Costa Rica.

And it looks at a very specific subset of insects called parasitoid wasps. And they're really diverse. There are these, like, tiny wasps, like really, really tiny. Like millimeters tiny, says Melissa Guzman, an entomologist at Cornell University. And these itty-bitty wasps are called parasitoids because they lay their eggs in or on other species, like caterpillars. Can I say something? I saw a was a was to a cicada in my backyard, and it was horrifying. It was like alien in real life.

Oh, my gosh. It blew my mind. Life finds a way. But don't worry. These are not hatching out of human chests. Good. It's going to be okay. Okay, okay.

Yeah, yeah, for now. But because these waspher are so small, it's, like, really hard to tell one species from another. So the scientists looked at a specific sequence of DNA from these wasps, and using that and some fancy modeling, they estimated there are 3,400 different species of one subfamily of parasitoid wasps in this one nature reserve. What? A lot. Yes, a lot. But scientists wanted to take it a step further to get a sense of how many types of all insects there were in the

reserve in Costa Rica. So they use that modeling and a larger sample of insects to get a number. And then they use that number to try to solve this big scientific mystery, Scott. I love myself a good big scientific mystery. Which one was this? So scientists wanted to know how many species of insects existed on the entire planet. And the best estimate to this point, based on studies of beetles, is that there are roughly six million. And for perspective, Scott, even the most generous estimates of how many bird species there are on the planet suggest only about 20,000. Okay, so it's more than 6 million, I'm assuming, is where this is heading.

Yes. So this new study published in the proceedings of the National Academy of Sciences suggests that that 6 million number, you are right, Scott, is a huge undercount. How many insect species are there on Earth? Yeah, between 14 and 20 million, at minimum. So up to three times as many species as previously believed. Here's Melissa again. There's so much that we don't know, right? And I think it's humbling just to get a sense of how much we have yet to discover.

That's wild. But what do you do next? Do you have like an insect census? How do you try and verify this in any way? I mean, yes. There's like a lot of uncertainty with this kind of modeling. And, you know, we've only taxonomically described about one million insects so far. So, you know, do the math.

It would take a lot, a lot, a lot of work. Okay. Next topic. Quasars, fun word to say. Cool thing. Remind us what they are. Yeah. So they are blazing bright centers of galaxies, and at the center of that is a super massive black hole.

Millions of billions of times the mass of our sun. And dust and gas is spiraling into that black hole. It heats up and starts to glow. So when astronomers see these quasars, the light that they see is... A supermassive black hole caught in the act of feeding. What an amazing thing to think about. Yeah. So that's Damien Young.

He's the first author of the study out this week in the journal astronomy and astrophysics, which reports the discovery of 31 quasars. And these are among the oldest quasars ever found. And before this study, astronomers only knew a handful of quasars this old. Yeah, and Scott, something that's kind of cool about this, is that these were all found with a space telescope that not a lot of people know exist. It's called Euclid. The European Space Agency launched it in 2023. And although it isn't as powerful as the Hubble Space Telescope or James Webb, it was designed to scan large swaths of the sky, which makes it really awesome at finding rare objects.

I mean, this is a cool thing to think about and envision, but I assume astronomers need a little more than this is cool for doing this work. Like, what is the practical value of spending time trying to ID these? Yeah, so these quasars are from, like, soon after the Big Bang. They're much bigger and brighter than astronomers would expect them to be that early in the universe. So Da Ming says there's a lot of questions about how they got so big, so fast. Like, what are they grown from? How did they grow?

like these questions, by only collecting more of these quasars, we can answer this. And these ancient quasars might tell scientists more of the era when stars were born from the primordial hot goo that occurred after the Big Bang. We will save the primordial hot goo for another day. Yes. And let's move on to topic three. Wolves. Yes, an animal that is often controversial, wherever it is cohabitating with people. You know, whether that's in the Western U.S. where I am, the Midwest or Europe, you name it.

Yeah, and a new study out this week in the journal Plus One is not going to soothe any of that hate some people feel about this predator. Hmm, why is that? So this study focuses specifically on wolves in California, which have migrated here from Oregon. And it looks at the impact they're having on cattle and, consequently, people, ranchers. Yeah, and researchers at UC Davis did a DNA analysis of the scat, you know, their poop from two wolf packs in 2022 and 2023 to see what they were eating. In both years, Scott, they found that the problem. primary food source for these packs was cattle. I mean, I guess my reaction, I'm not super surprised by that, right?

Because that's the particular reason that ranchers have such stark feelings about wolves. Like, what am I missing? That's reasonable to think, but it's uncommon for livestock to be the primary food for these wolves. So Tina Sightone, the studies lead author, says in most states, wolves predominantly eat wild game. But when wolves come to a human-dominated landscape like California with very little prey, You're going to see a very different composition of prey. So in other words, you know, California doesn't have big populations of elk like Montana or Wyoming. We don't have as many deer as there are in the Midwest or the northwest.

So the wolves just don't have a choice then. Is that it? Yeah, that's right. So Neil Carter, who studies wolves at the University of Michigan, says this study, which he wasn't involved with, underscores how complicated it is for carnivores to come back to places that have fundamentally changed. If you want to have these animals on the landscape, You know, you have to start kind of building back the full ecosystem. Which in California would mean boosting mule deer populations, which are currently declining because of habitat loss, boosting other game species like elk that the wolves can eat. And look, that's not something that could happen overnight.

But I think this study does give the people that manage wildlife and want to see fewer conflicts between wolves and humans, something to think about and to aim for. Scott, I hope you enjoyed this, you know, not space segment, but, you know, news segment. And a little bit of space. A little bit of space. Just enough. Just enough. I'll be back soon for spacing out. But in the meantime, always love being here.

Yeah, come back anytime. Yeah, thanks, man. You can hear more of Scott Detrow on Consider This and PR's afternoon podcast about what the news means for you. And for more signed stories, just like this one, follow shortwave on whatever app you're listening to. This episode was produced by Rachel Carlson and Jordan Marie Smith. It was edited by Rebecca Ramirez and Christopher in Taliatta. Tyler Jones checked the facts. Anli Wong and Tiffany Vera Castro were the audio engineers.

I'm Nate Rot. And I'm Regina Barber. Thank you for listening to Shorewave, the science podcast from NPR.