Ologies with Alie Ward - Smologies #43: CICADAS with Gene Kritsky

Episode Date: May 6, 2024

They are numerous. They are patient. They are COMING for the United States in droves this spring: They are cicadas. *The* Cicada guy Dr. Gene Kritsky joins to chat all about the annual cicadas you may see every summer vs. the periodical ones that cycle through the states in broods of giant numbers. Learn how they survive underground for decades, what they are doing down there, all about their lifecycle, why some cozy up underground for 17 years while others get moving 4 years quicker, plus get inspired to take a cicada safari, download Cicada Safari, and appreciate their songs, which can be as loud as an ambulance. By the end, you’ll want to don a bug costume and take a road trip to one of the 18 states expecting a periodical emergence this spring!Dr. Gene Kritsky’s new cicada book A Tale of Two Broods: The 2024 Emergence of Periodical Cicada Broods XIII and XIXDownload the Cicada Safari app at the Apple Store or Google Play Store.Check out Gene’s websiteAlso see CicadaMania.com, and follow them on InstagramA donation was made to Mount Saint Joseph’s cicada research in the School of Behavioral and Natural SciencesFull-length (*not* G-rated) Cicadology episode + tons of science linksMore kid-friendly Smologies episodes!Become a patron of Ologies for as little as a buck a monthOlogiesMerch.com has hats, shirts, masks, totes!Follow @Ologies on X and InstagramFollow @AlieWard on X and InstagramSound editing by Mercedes Maitland of Maitland Audio Productions, Jarrett Sleeper of MindJam Media and Steven Ray MorrisMade possible by work from Noel Dilworth, Susan Hale, Kelly R. Dwyer, Emily White, & Erin TalbertSmologies theme song by Harold Malcolm

Oh, hello, this is Smologies. If you're like, what is that? Smologies are digests of classic episodes. We've taken a classic episode that was for adults sometimes, and we've cut them down so they're shorter, they're kids safe, they're G-rated. Okay? They're just for you. This one about cicadas. Love this one.

Cicadas are back, and so we're making this as Smologies for you. So do enjoy. If you want the full length, all the details, including some swearing, you can find the original full length, all the details, including some swearing, you can find the original full length version at the link in the show notes. But for now, this is just a shorty, Smologies. Oh hey, it's your friend's older sister, Ali Ward.

Back with an episode I have waited most of my life for, no exaggeration. When I first came up with allogies as a concept, it was partly just to trick an expert into talking to me about cicadas. Okay, let's get to cicadology. Cicada in Latin means tree cricket, but your Appalachian friends may call them jar flies, I just found out.

I have only seen a cicada in the wild maybe three times in my life, and each time I crowded around it and gasped and took pictures like an American at the Eiffel Tower. I have never even seen a periodical cicada, the ones that emerge in the trillions every 13 or 17 years in the U.S. So this year, we're getting ahead of their emergence. And thisologist, who is the authority on periodical cicadas, he hails from North Dakota. He's written multiple bug books and authored scores of papers on insects. He is the cicada guy. So he typically appears in the news.

Sometimes maybe you've seen him in all khaki field gear and a tan sun hat. And he has a gentle silver beard with kind of a tidy upturned mustache, like a friendly smile. And we hopped on a call to record and I just screwed it up so bad, like immediately. I dropped off the connection and I could not log back in and there were all these tech hiccups. So I texted our wonderful assistant scheduler, Noel Dilworth. I said, hey, I sent him a new link, but he hasn't shown up, but I hope he's not mad.

And then I got the reply, I am not distressed. And I had texted him that instead of Noelle. So between wanting to do this episode for 17 years, and then talking to the world expert in it, and texting him about him, my level of body sweat was clinically dangerous. But regardless, we figured it out. We got on the line to chat about life cycles and ghostly remains, cicada chasing the decibel levels of our springtime friends. And what you should do if you see a cicada, the app Cicada Safari, and what they are doing underground for nearly two decades while we miss them with icon, legend, and sick-hatologist Dr. Gene

Kritsky who may or may not already be mad at me. Smologies. Smologies. Smologies. Smologies. Smologies. Smologies. Oh my god. Are you mad at me? Why would I be mad? I don't know. I felt so mad. I was like, oh no, maybe he just left forever. I was mortified when I realized that went to you, but secret's out.

I'm a human being. That's all right. So am I. All right. Down to business. I'm Gene Kritsky and I use he, him. And now can you tell me a little bit about what we can expect this year from the cicada population in the United States? We'll start seeing our first sign of cicadas in late April after a big heavy rain. Some of the cicadas, especially the soil is a very heavy clay soil, they'll actually extend their tunnels above ground.

They're called chimneys or turrets, very similar to what crayfish will sometimes do. News flashed to me that crawdads, aka crayfish, emerge sometimes out of tall lumpy turrets they build. And also, I googled cicada tunnels. And one image taken under a deck looked like a coral reef or like big tall stacks of dirty poker chips. Or like the tallest birthday cake ever out of which a beautiful ghoul pops up to say happy 17 years day! Surprise! But that's the first sign that we'll see that'll be usually in late April.

They come out of the soil when the soil temperature reaches 64 degrees Fahrenheit. And then very specific. Very specific. Well, these are cicadas. You know, they got they got things to do. They got to come out in 17 years and keep track of numbers and what have you. Once you hit that temperature for 64 degrees Fahrenheit, and then you have a really nice soaking rain that just sort of saturates everything, then they really pop. I mean, it's just, it's amazing.

The highest density I've ever seen was 356 per square yard. And that was over the course of about a two week period. They kept it. But the first evening they come up by the hundreds and thousands. They were, if there was as much larger, you could probably have a really good sci-fi movie. Well, what's the difference between a periodical cicada that might come out every 17 years or 13 years and annual cicadas? They belong to different genera.

But if you want to look at them, you'll find that the annual cicadas, some are called dog day cicadas because they come out of the dog days of summer. They're much larger. Their head is more flat. Their eyes are black, so it has green flat, their eyes are black, sometimes green, many of them are black with brown markings or black with green markings, they look more camouflaged. And as I say, they're about a half inch to an inch larger than the periodicals.

So the annual ones come out in the heat of summer every year, and although they are more chunk, you won't see their camouflaged bods as readily and you will not witness anything Near the numbers of the periodical cicadas the annual ones are just all in all more low-key Is that part of their evolutionary strategy is just a ton of them at once. How does that work? Well, it's it's works well for them It's called predator satiation is what we think is happening. They come out in these large numbers. Some of the birds are major predators of them, but their little crops can't hold many more cicadas.

And the analogy I like to use is imagine walking outside and all of a sudden you see the whole world is inundated with flying Hershey's Kisses. I'm fond of Hershey's Kisses. And you would tend to eat and eat and eat and eat and eat some of these. But eventually you will get tired of them. And 1991 and route 14 emergency. I saw this dog the first day they're coming snapping out of all over the yard, you know, just going at him. Five days later, go back to see how the emergency is

going on at some of my test sites. And that dog is just lying on the porch. Paws folded and cicadas walking all around him. Does not carry over it. I'm over these things. So, periodical cicadas are in the genus Magicicata and they make a splash. They are smaller than the annual cicadas, but they have such style in the form of blood red eyes. And there's billions, maybe trillions of them. In fact, their genus looks like magic cicada,

but magi actually comes from the Latin for many, not from the word magic. But there are over a dozen 17-year broods and a small handful of 13-year broods. And I'm going to link on my website to a US map to see which broods might be in your area. Now, elsewhere in the world, you can always gaze at an annual cicada if you have them.

You can tell you love it if you can find it. But if you have periodicals in your area, they're hard to miss because they blanket everything. And this is one thing I think that still mystifies us. But can you describe a little bit of the life cycle? What are they doing that whole time? Let's start when the adults emerge from the ground. But what will happen, as I mentioned, the soil will be 64 degrees

Fahrenheit, nice soaking rain, and that causes the nymphaline cicadas to come out of the ground. They start wandering on trying to find a vertical surface to crawl up because our whole purpose now is to shed their nymphal skin and transform to the adult. I've seen them crawl up trees our whole purpose now is to shed their nymphal skin and transform to the adult. I've seen them crawl up trees, brick walls, fence walls, tombstones, blades of grass, whatever. They climb up that surface and they lock their little legs

into the tree trunk, let's say it's a tree, and then all of a sudden the back of the thorax splits open like somebody wearing a black coat or with a white shirt underneath it, that's just too small, they split the seam. You see this thing open up, and then it goes up and cracks the head capsule, and then slowly the adult cicada wriggles its way out.

And by this time it's out, it's white in color, it's got red eyes, two black patches behind the head, and then they'll eventually look like the typical adult cicada, with the red eyes and the black body and the memberless wings with the orange color on the major wing veins at the base. And then the thing it wants to do now is basically climb to the tops of the trees and then they start flying and that's when you'll see the birds really attune to them. And at

this time more males emerge the first couple days than females. That vanguard there is going to give their lives so that others can live. So the early male gets the axe. Just first on the scene, looking for ladies. They are delicious. They're like the first french fry you eat out of the drive-thru. Just the least likely to survive. And males and females will sprout out over the next couple weeks, all looking for springtime,

summer loving. And after about five days or so after they've emerged, the males could start singing. Yes, I have so many questions about this. When you say singing, what would you say that it sounds like? It's beautiful. Yeah, I love it. I think it sounds kind of otherworldly to me,

just this really kind of high-pitched buzzing. Yeah, it's very much so. There are three species that are called that are different from the three species. The large one, Septindessum, has a sort of like barrel. And it sounds like when you hear a whole chorus of these things, it sounds like some 1950s science fiction movie. That's the sound of the flying saucers flying in. Yeah. And then the smaller species,

castanets is more of a constant shh. Shhh sound. And it doesn't all stay constant in sound and levels. It'll get louder and then drop off, louder drop off. The highest I've measured is 96 decibels. Ooh, my gosh. That's about as loud as like a rock band playing, right? As a rock band. I've never been more like your old uncle. But yes, different calls like the ones on the wonderful, incredible website Cicada Mania, run by Dan Mosgai, hit different decibel levels. And some are said to approach 120 decibels, which I looked it up, and that is a volume

of an ambulance siren. So man bugs. Screaming for love. Mount St. Joe is on the flight path. This is an international airport. And cicadas will drown out the jets. Wow. How are they making that loud of a sound? The sound is made by a timble.

There are two timbles on the first abdominal segment of the male. And then the male's abdomen is mostly hollow. And so that acts almost like a resonator to get a little louder. Think of the belly of a stringed instrument. So there is a reason a violin or acoustic guitar is hollow. And you put 10, 20,000 of these in one tree, it's going to add up. And the sound, if you've ever taken the bendy straw, you know, the one that has, and you can, you pull it out, you hear that little snapping sound, do that about 150, 200 times in a second. And that's your call for that

mail amplified with the abdomen being hollow, and then multiply that by 20,000, and you might have a good example of a chorus. Yeah, oh my gosh, oh. And also, apparently, if you are hosting a boy's cicada on your hand, and you want to prompt it to perform, try snapping your fingers at it.

It will mistake the sound for a lady, and then try to your fingers at it. It will mistake the sound for a lady and then try to impress you by screaming. And now what happens when she is gravid or preggers? What happens? Well then she's got to find a place to lay her eggs. Okay. And she will lay her eggs in the new growth of trees and she has a structure called an ovipositor which is a structure at the tip of her abdomen, which she pulls out of a slit

at the tip of her abdomen, and then literally, it has a central rod, and on each side are two structures that are serrated, and they move opposite each other, and literally cut into the wood. And it turns out they are also, like we see with the conneumodated wasps, that lather eggs that are bark and so on,

also reinforced with metals, and these metals are increased along the side of the serrations. So they're armored cicadas. Oh, wow. Oh, that's amazing. I'm just gonna restate that for all of us. So cicada ladies ovipositors are serrated like knives

and reinforced with metal, also like a knife. She'll lay between 10 to 20 eggs in each little egg nester. It's about a quarter of an inch long, walk another quarter down, puncture the tree twig again, lay more eggs and so on. And she keeps doing that until she either runs out of a branch, then she has to fly to another one, and eventually runs out of eggs. But they still have quite a trek to make, right?

They do. After she lays her eggs, they die. And both the male is dead, and the female then drops dead and that's it. And it takes six to eight weeks after the eggs were laid that they'll start hatching. And that's usually the end of July, 1st of August. If you're at the right time, the right place when the eggs are hatching and the nymphs crawl out of there, the egg nest, and the sun is the right ankle, you

can actually see these things drop like little little flecks to the ground. And that's when they're extremely vulnerable. Spiders, ants, ground beetles go after these things like crazy. So as soon as they hit the ground, they've got to find a crack in the soil, that's usually along a blade of grass, and they get underground immediately as fast as they can. So yes, eggs are laid in slits in tree twigs and then they emerge and once on the ground they start looking for 13 or 17 year real estate. And so they feed on

grassroots for the first few weeks and then by New Year's Day they're 10 to 12 inches below the surface latched onto a tree root sucking. And I know it because on New Year's Day I went out and dug up cicadas. Really? So they've already latched on there. So do they spend those cold winters just sucking up sugars from the tree roots? Well, yes, but they're feeding on the xylem tissue. And as you remember from biology, xylem is the water conducting tissue

that brings water and minerals from the soil up to the leaves. The phloem has the sugars coming down. So they're feeding on this nutrient poor fluid for the next 17 years and not moving probably more than a yard or a meter in any direction during that time. Got everything I need right here with me. It's thought that the long life cycle might be a response to their evolving and adapting to the ice ages. Really? Yeah, okay. So tell me a little bit about that,

about these long life cycles and how they know when to come out. The life cycles, well, there's two life cycles, 17 years and 13 years. And they grow at different rates. One of the differences between 13 and 17 years cicadas is that the 13 years cicadas molt an extra time within that first five years of life. Oh, okay.

And that triggers their coming out four years early. But the idea is that the 13-year cicadas evolved south of the glaciers, and if you look at the 13-year cicada distribution, they're mostly in the southern part of the eastern United States. But then the 17-year cicadas are generally more north than that. Although there are some of that in eastern Oklahoma that get a little far south. So Gene explained that cicadas are generally more north than that. Although there are some that in Eastern Oklahoma that get a little far south. So Gene explained that cicadas are creatures of climate, evolving and separating into different species

and broods and groups relatively recently in the last ice ages, adapting to ice sheets and going further south and then advancing north again when they receded. And the 13 and 17-year periodical cicadas separated over the last 300,000 years, which geologically speaking is pretty recently, and then further split into the three 13-year broods and 12 17-year broods. Can I ask you questions from listeners?

Sotrly. But before we do, a quick note about sponsors of the show. Because of them, we can toss a cicada load of money at a worthy cause each week. And this week, Dr. Kretzky requested it to go to Mount St. Joseph's University in Cincinnati School of Behavioral and Natural Sciences. And Gene says, you can designate it for cicada research. Our VP will be shocked. So let's do that.

Now, if you feel like tossing a few bucks that way, there's going to be a link in the show notes. And thank you to the following sponsors for allowing this podcast to donate. Okay, many patrons such as first time question askers Molly Cousins and Alex Bowman wanted to know how are they better at time management than people essentially? How do they know when to come out? Is there a stage manager underground? What's happening? Do you have any idea? Do scientists know if there's something chemical that triggers that emergence? How do they sense it? We know that they can determine year passages by the changes in fluid flow in the xylem. When the tree goes dormant,

there seems to be some that they can detect that. Leaf sets and flower sets can trigger that because you'll see more fluid flow. But what we don't know is how do they remember what year it is? Mm hmm. We did have an event happen here in Cincinnati in 2006. We had a December that reached 70 degrees and it continued into January. And the maple tree in my backyard leafed out. I thought it was just amazing. This is January. Then we had a hard freeze in February,

all the leaves fell off. Come the late March, early April, the trees started leafing out again. And in parts of Cincinnati, where brood 14 was expected to come out the following year, they came out. So for those cicadas, they thought 17 years had passed, even though they had two leaf sets that occurred in one year. For more on how leaves come and go, by the way, check out the Phenology episode.

Also heads up to Hannah Neust, I'm about to pronounce your name wrong and I am sorry. And so this dovetails into a question from several listeners. First time question asker David Ordanoff, first timer Hunter Elliott, Hannah Neust and Earl of Grimelkin all wanted to know in well in Earl's words not to be depressing But to be depressing how is climate change affecting? Cicadas and a hunter wanted to know could their hibernation cycles be altered because of it That's one of these that we're looking into and it seems possible as I mentioned they are Climate insects if you will they emerge when the soil temperature reaches 64 degrees Fahrenheit and prior to 1950 the average for Cincinnati was May 28th 29th since

1950 and in the last few years they're now coming around between the 13th and the 16th of May. So spring is now two weeks warmer than we were back in the first half of the 20th century. What that could do, for example, if you had continuous, like what happened in 2006 to 2007, if you had a year event happen where there was like trees that seemed to the cicada, if a two year things had passed, they might molt in that first five years, which would trigger a four year early acceleration

of the merging off cycle. And that's actually happened. In 1991, my students in my ecology and evolution classes know that we would go out to the orchard at the university and we'd dig up cicada nests. To sort of drive home the scientific method, I gave this wonderful paper written by Monty Lloyd and Joanne White. It talked about the difference between 13-year cicadas and 17-year cicadas.

And it said what stage of growth they should be at each year. And I said, OK, what stage should they be at? And then we got shovels and went out and dug up cicadas. And the skaters were bigger than they should have been. So what that meant to me was, they're going to come out four years early, and they came out. Oh, and massive numbers. It was mind boggling. What's going to happen to that one? Is it going to get off cycle now?

Or is it going to step in line with the rest? Oh, that's what we wanted to know. So of course, working with cicadas, that's the problem. This is to the year 2000. Yeah. So I went back in 2013, my wife and I went to the study site and they started coming out, they're coming out, we found shells all over the place, we went out there and even the hundreds of them came out. But go back the next day, we couldn't find a single adult cicada.

Those cicadas did not survive predation to reproduce in 2013. Wow. Wait four more years. Now you remember, this is now 17 years later. So this last early emergence happened in 2017 and adult cicadas who were just little baby eggs in that early 2000 emergence emergence made it all around Cincinnati

and their babies were on time 17 years later and not in one backyard, but at 33 different locations recorded. So what happens to all these early bird cicadas? Things are out of sync. What we've seen now is the origin of a new population of brood six. Oh, wow. patron David Ordonoff asks, Are we looking at dwindling

populations? So what kind of headcount are we talking? It's sort of interesting. In 1919, headlines and newspapers around the country talked about brood 10s emerging, it's probably on its way out. There's concern about it's going extinct. As crazy as that sounds, it's happened. Brute 11, which emerged in massive numbers, the 1699, just outside of Boston, went extinct in 1954. Wow.

Here in Ohio, in Northwest Ohio, several counties that reported cicadas in the late 19th century, early 20th century no longer have cicadas. So one of the things I'm hoping that we do with people helping us with the cicada safari app is to really give us a good picture. What's the status of Brew10?

And so now people can download cicada safari and they take a picture and let you know where they took it, like geo-tagged it. Yeah, we wanna do two things. We wanna help people have more enjoyment with the cicadas. So after you've downloaded the app and it's free, we encourage people to go on their own cicada safari. And if they see one, they take a photograph and submit it.

I've got a group of colleagues who are volunteering and working to help us identify and examine every photograph. US Oligites, do your thing. Cicadas for app. I know that there's so much that you love about them, but is there something that is your favorite thing about cicadas? Oh, wow. I know.

There is something about when they first start coming out, I will go out with my tripod, my iPhone flashlight, and I'll set this thing up and I'll sit there for hours photographing a cicada as it goes. I've got probably 20,000 pictures of this now. But it never gets old. It never gets old. And that's almost like a zen moment when you can do, when that happens.

And then to the opposite extreme, but still fun, is when the numbers are really big and they're screaming. And it is just fun. It is just great. So ask world-renowned experts basic questions, even if you have to wait 17 years to do so, and you screwed up for the first couple minutes. At the link in the show notes, you will find the app Cicada Safari and you can help Gene's lab track these suckers. You can learn more about cicadas from Dan Moskai's website Cicatamania which is wonderful and he has an Instagram Instagram.com

slash cicatamania highly recommend following them and I am Ali Ward on Twitter and Instagram with just one L and the show is at Ologies on Twitter Instagram. Also linked is Ali Ward.com slash Smology's which has dozens more kids safe and shorter episodes you can blaze through and thank you Mercedes Maitland of Maitland Audio for editing those and since we like to keep things small around here the rest of the credits are in the show notes. And if you stick around until the end of the episode you know that I give you a piece of advice. And this piece of advice is that if you love bugs

and you love taking pictures of them, you might want to ask a grownup, maybe for your next birthday, for like a little macro lens that you can clip on to a phone or an iPad. You can take up close pictures of bugs. Even the smallest patch of dirt becomes fascinating with that.

But you can also just get up close with any kind of camera and check out and see what's under leaves, what's on the underside of a branch. There are so many bugs hanging out everywhere. And you'd be surprised. You can go on a bug safari with the smallest little patch of lawn. So enjoy.

I love doing that. I'll sit in the garden. I'll just be like, who's out here? Boom. I got 10 new friends in a second. All right. bye bye. Smology. Smology.

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