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A buzzworthy emergence: Entomologist Austin Jones discusses historic cicada swarm

Last night was the Equinox, which means spring has officially begun. As temperatures rise later in April, a familiar sound will fill northwest Arkansas’ forests and grasslands: the raucous buzz of cicadas. These insects have an unusually long life cycle that requires more than a decade of maturing underground. However, as your eardrums know, cicadas eventually emerge, and this year’s crop of noisemakers will be a little different for some parts of the country. For the first time in more than 200 years, two particular cicada species will emerge from the earth simultaneously, producing a swarm of trillions. 

Ozarks at Large’s Jack Travis sat down with University of Arkansas entomology instructor Austin Jones to learn more about cicadas and this year’s historic population boom. Jones is now dedicated to invertebrates and their study, but he says he wasn’t always this passionate about bugs. He can trace his interest back to an entomology course in college.

The following is an edited transcript of that conversation.

Austin Jones: And I thought, that sounds like an easy A. I know what bugs are- I grew up in the woods. And so, I signed up for it thinking I was going to sleep through it like I did my weather class. And we had to do a bug collection. And every time I went outside with my net, I saw something I had never seen before. And it blew my mind that all this had been around me my whole life. And I was unaware. And so it seemed like the right field of study for me because I love being outside. I love animals. You know, a lot of people don't even consider bugs to be animals, but they don't have a lot of the same rights that vertebrate animals do. But the thought of having something that I could study anywhere was what intrigued me about them. I love the diversity of insects.

Jack Travis: We're going to be getting a whole lot more insects here coming up pretty soon. So, I was wondering if you could just kind of set the scene for our listeners regarding the cicada co-emergence. Why is it so rare? When is it happening? Why do these creatures do an emergence like this? I know that there's some background to that.

Jones: Absolutely. So periodical cicadas are kind of their own group within the family known as Cicadidae. There are about 3000 species of cicadas worldwide. There are about 175 species in the US. There are said to be about two dozen species in Arkansas. So, we've got a good diversity of them here. Magic cicada is the genus of the cicadas known as periodical cicadas. So the ones that we hear about come out in mass emergencies, those come out on two different cycles, some of them come out on 13-year cycles, some of them come out on 17-year cycles. The genetics behind that is really fascinating. We still haven't fully figured out what's going on with the genetics of these emergencies. But what makes this year so buzzworthy, as it were, and cicada comes from the Latin for to buzz. What makes it buzzworthy is that we have two large broods that are coming out in the same year. And with these being prime numbers 13 and 17. That doesn't happen very often. So actually, this would be the first time that these two broods have come out together in 221 years. Now, that sounds awe-inspiring. And especially if you've lived through one of these events before, you know there are billions of these bugs out and about. But with the co-emergence, it's really not going to make that seem more intense in any one location. It just increases the geographical range of where they're going to be emerging. So we have brood. I always get these numbers confused. I believe it's Brood 19 that's coming out in Arkansas this year, their 13-year cicadas, and that's the largest of all the broods that come out. It's going to be synchronous with brood, a northern brood. I think it's Brood 13. And there are only a few areas where you may have an increased population from a normal emergency here and that would be we're about halfway up Illinois, the state of Illinois. So if you live around like Springfield area of Illinois, you may have cicadas both north and south of you coming out that you wouldn't experience on a normal emergence here, but anywhere else, it's just gonna be like a normal periodical emergence.

Travis: Okay, so even though you're in northwest Arkansas and you won't really be experiencing anything different from what normally happens, what are your emotions leading into this? Because, on an entomological level, it's like you said, it's every couple of centuries that this happens. What are your emotions going into this? What's on your mind?

Jones: Well, I am always trying to come up with what kind of questions we could answer from these periodical emergencies because they only happen so rarely. You know, what can we find out about the synchronicity of this in the future? What can we say about how our environment has maintained stability since the last emergence? Cicadas are kind of unique insects because most insects rely not only on time but also on temperature to reach their developmental thresholds. So I set before you, as a 40-year-old person, we measure our development in time. But if I was an insect, had I been raised near the equator where it was hot all the time, I may look like I'm 60 right now. And if I was raised in a more northern environment where I couldn't accrue as much heat energy, I might still look like I'm 20. So temperature has a direct effect on almost all arthropod development. But what's unique about the periodical cicadas is that no matter how fast those nymphs have been growing, they seem to know to all come out together. Whether they've accrued enough heat or enough nutrition, they think that perhaps they count the seasons by knowing the different chemical cycles of the plants they're feeding on. But it's really unique to me that, say, this batch of cicadas was already ready to go a few years before the emergence. They may just be holding on until the rest of their cohort has gained enough nutrition to come out all at once. And the reason that's important is because a periodical cicada emergence has, for what all we know one driving force, and that's to overcome predators. And that's one of the reasons that they've maintained in these periodical cycles is yes, we have groups of cicadas that can emerge off year, one year or four years are the most common. But when these appear kind of off year, there may not be enough of them to overwhelm predators to start another brood as it were to go down that cycle. When I think of this happening, I think of the last two times this has happened in my life and how vivid memories I have of those things. So since we have a 13-year emergence that's happening here, I look back to, you know, 26 years ago or so, when I was just a kid, and I was seeing all these cicadas just buzzing around certain sites where males will congregate to try to be as loud as they can to draw in females to those areas. And just feeling like the whole forest was vibrating around me. Cut scene to the next time it happened. I was about 27 years old, and one of my hobbies at the time was catfishing. I really liked setting limb lines and going out and checking them for catfish. That summer, when these things emerge in late May or early June. It is such a pulse of nutrition for wildlife. I mean, these things have been growing underground, relatively inaccessible to predators, for a long time. You know, most insects live less than a year for their lifecycle. And so when they come out, everything that consumes insects is going to have a feast. Every catfish that I caught that year had a belly full of cicada nymphs that had been washed into the lake. Birds eat them, foxes eat them, copperhead snakes eat them, frogs eat them, and there are even parasites and parasitoids that rely on them for their life cycles as well.

Travis: So where can you know? You mentioned that. I mean, it's not like we're going to see anything different, right? But where could—if someone was interested, where should someone go to maybe experience—they won't see the co-emergence on the scale that you might expect. But where could they go to experience what you’re talking about, seeing the forest buzz around you?

Jones: Anywhere that you're gonna have a good canopy cover forest has the potential of becoming a site for these males to congregate. anywhere on the Ozark Plateau that has a wooded area within reach- I think it would be a good place to see this happening. There's actually these broods that come out actually contain multiple species within the same genus that come out sometimes. The way that we kind of ID them is by the pitch of their song- some will have a slightly higher pitch, and some will have a slightly lower pitch. In the year 2000, there were two researchers from Michigan who came to Arkansas to record their songs during an emergence. And they actually hypothesized that there was another species that hadn't been IDT that was calling in northern Arkansas. So Arkansas actually could have as many as four species of cicadas all coming out with this one brood that happens this year.

Travis: What's the significance of that?

Jones: You know, genetically, it's kind of a conundrum. And I think that's really the significance of it is finding out what is the driving factor for these broods, maintaining, and coming out on the cycles that they do. There are three species of 17-year cicadas, and there are four species of 13-year cicadas. But each 13 year cicada has a closer relative in the 17 year cycle, they have they have names like, like desam, and trace in the species names to indicate whether they come out 17 or 14 years apart. But as I mentioned, sometimes these come out off-cycle, and you can actually have some 13-year cicadas that don't come out until 17 years or vice versa. And I think the significance is trying to unlock the puzzle that created this scenario in the first place. I mean, they've done a lot of genetic testing to find that all these populations were probably one population 4 million years ago and that whatever's happened has happened since that time. It says something about the natural history of the Eastern US, in particular, how forests arrived and how moisture was redistributed around the country. And then trying to understand how these things are coming out as multiple species as one brood but still maintaining their genetic viability as species and not all just hybridizing and becoming one thing. So to me once, it's kind of like what intrigued me about entomology, it seems like it's an infinite area of study. And when you only get to collect data points every 13 Or seven teen years, it may be a long time before we can put enough data points together to answer some of those questions.

Travis: So, remind me again when this will be taking place.

Jones: This will be happening. You may have some come out towards the end of April. But I would expect it to happen more around Memorial Day, when I'm kind of pinpointing that they like a certain soil temperature for them all to be emerging at once. I don't remember the exact temperature Fahrenheit, but I think it's somewhere around 67 degrees. Soil temperature, something like that, is when they're going to be emerging.

Travis: So, how will you be spending your time?

Jones: Well, we've got a lot of big events coming up this spring, we've got the total solar eclipse that's happening in April, and then we've got this that's going to be happening a little later in the year. I tell you, I'm going to be spending as much time in the woods as I can. And I'm probably going to be trying to drum up some sort of a special problems or special topics course where we could get some folks out into the field recording some songs, gathering some specimens. I've even got one student right now talking about wanting to try some new recipes on the cicada nymphs as they're emerging because that's one of the things a lot of folks like to try some cicadas as snacks when they come out of the ground. You know, there are lots of edible insects. They can be great sources of fat and protein. And I believe it was a maple chili recipe that one of my students wants to try this spring.

Travis: Will you be trying?

Jones: I would Yeah, if somebody fried up some cicadas, I definitely give it a shot. Am I going to go that far as to do it myself? Probably not this year, but you never know.

Travis: Well, I look forward to hearing how that tastes. Before we stop, is there anything I forgot to ask or anything else that you felt was worthy to mention?

Jones: Gosh, let's see. So you know, people think about cicadas as being this mass emergence. But know that most cicadas in the state have them coming out every year. Of those two dozen species, we have. Most of them are kind of camouflaged in color and a couple of inches long. But they have unique calls for their species. And you can go online and find websites that have all the recordings so that you can ID what species you have by their call. And some cicadas we have here are grassland specialists, they only get to be about a quarter to a half inch long. And so that's kind of the small size, small into the realm of size for cicadas in the state. But cicadas, in general, are probably my favorite sound on the planet for whatever reason, only the males make the noise. They have hollowed out their thorax, and their body chamber has become a hem-Holtz resonator to amplify sound as best they can to be heard by their potential mates, which don't have that same sound-making capability. The females cannot make that noise. It's only the males you're going to be hearing. Males are expendable. When you're making noise. You're letting predators know where you are, too. And so the same thing with crickets. It's only the males that make the call. And then the females make the decision as to who's making that call, the best call.

Ozarks at Large transcripts are created on a rush deadline by reporters. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of KUAF programming is the audio record.

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Jack Travis is a reporter for <i>Ozarks at Large</i>.<br/>
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