A Disgruntled Q&A with a Cicada Expert

Apr 28, 2021 at 10:36 am
Photo by John Ghent, Bugwood.org.
Photo by John Ghent, Bugwood.org.

When I heard a large amount of cicadas, Brood X, were reemerging this year after 17 years, I was disappointed and then incensed. Here I was, with one dose of the Pfizer vaccine in my arm and plans to go camping with my similarly COVID-safe friends after a year of relative isolation, and some bug-eyed arthropods were going to ruin that for me? My mind flashed to 2004, a summer when I was scared to leave my house. I was 9 and used to spending my time off school at the pool or reading outside. Instead, I watched from a window as my brothers waged war with the insurgent buggers. 

I expect many of us are feeling similarly: “So, I’m finally allowed to leave my house, and this is going to happen? Another plague of a different kind?” Logically, I know there must be some scientific benefit to having the cicadas return. So, I turned to someone who I thought could make me feel better: Jonathan Larson, or @bugmanjon on Twitter, a UK extension entomologist who also co-hosts a podcast: Arthro-Pod. Here I ask him my cicada questions, including the most important one: What did we do to deserve this? 

Jonathan Larson, UK extension entomologist.
Jonathan Larson, UK extension entomologist.

LEO: So the reason I’m not too psyched about these cicadas is that, it’s just this past year has been really tough for humanity, I think, with COVID confining us to our homes. And just as science has gifted us these wonderful vaccines that are going to allow us to reenter society, I receive news that there’s a large group of cicadas that are going to be emerging this year. So my first question is, is nature revolting against us? Jonathan Larson: I don’t think so. I think that this is more of a sign of the beauty of life, like this is another huge piece of nature that’s going to get to come out and experience their own sort of emergence, just like we are coming out of this coronavirus pandemic. They’ve been underground for 17 years, so they’ve had it a little longer than we have. I think it’s one of those beautiful, weird things that happens in nature. So, it’s just a sign of the fact that things are continuing, things are living and things are thriving.

Okay, so, if not a planned attack by the cicadas, or like the earth turning against us for the sins we’ve committed against it, why are they coming back this year?

That’s an excellent question. So this brood that’s coming out is called Brood X, and Brood X is made up of three species of 17 year cicadas. And that means that 17 years ago in 2004, the eggs were laid, their eggs hatched, they burrowed into the soil, they’ve been living down there below ground… And as a species, they have a time of emergence where they come out, 17 years after they go into the soil. So it’s just everything is going according to plan for them.

So because it’s three different species, it’s going to be larger than normal? A larger emergence of cicadas than in other years? Is that correct?

These are different species than the annual cicadas that we see every summer. So annual cicadas come out every summer in the middle and latter half of the summer. Those species tend to be larger; they tend to be sort of a green and brown and black mixture. And like I said, they come out later in the year. Brood X and the 17 year cicadas, they’re actually smaller than the annual cicadas. They’re all black; they have red eyes; and they have orange stripes on their wings. They look quite a bit different. And they emerge much earlier in the season compared to their cousins, the annual cicadas. 

I’m gonna be honest, the way you’re describing them…not enthusing me too much. But, what have they been doing in their underground lairs this entire time?

In their underground lairs they have been siphoning out tree sap from the roofs of their host trees. So they kind of feed on, especially maple syrup, all the live long day. They don’t have a very nutritious diet. It’s sort of like if we drink Dr. Pepper and Mountain Dew, and that was it every day in our life, we would probably take a long time to develop as well. So that’s what they’ve been doing, is they’ve just been sort of slowly feeding and developing, and then counting the cycle of the sap. So as the year progresses, the tree will have less sap at the lower part, and they can count that cycle, and that’s how they get to 17 and know that it’s time to emerge. 

So I’ve watched a lot of science fiction movies, and I feel like there is a message that you shouldn’t mess with nature. But hypothetically, is there a way to keep these cicadas from reemerging? Like, could we cover our yards in like the plastic wrap that old ladies put on their couches or something like that?

Could we Tupperware the whole world sort of? 

Yeah.

Unfortunately, we’ve kind of done that already, you know? When we talk about humanity and our interactions with the planet, we do a lot of urbanization. We’re in the Anthropocene, right — this whole idea that we are the ones dictating what happens. And we’ve taken away a lot of habitat from these already so they already emerged in fewer places than they used to seemingly. We’ve moved into their world rather than the other way around.

And what kind of effect does that have on the ecosystem, limiting their spread?

It’s an interesting question. It’s something that we ponder a lot in entomology: What is happening with these cicadas and their interactions with the rest of the wild world? It’s hard to say because they only appear every 17 years so they don’t have a huge presence every year, so there’s not a lot of things that depend on the cicadas. One of the reasons that we think that they do the 17 year thing, is that it helps to make sure nothing specializes on them. We don’t have something that only eats periodical cicadas or only lays its eggs in periodical cicadas just because that’s too long of a period for most predators and parasitoids to wait. So that’s an interesting thing about their biology. But if we have fewer of them, we also see that things have less of them to eat, and there’s a lot of things that like eating these cicadas: snakes, raccoons, squirrels, opossums, birds, turkeys, you name it. Anything with a mouth and the digestive tract basically likes to eat these. And so it’s a big huge protein surge that they get every 17 years, and it can help their populations. So they do have a role to play. They’re sort of a big nutritious snack that lots of things enjoy. I can’t go any more philosophically than that about what it is they do for the world, but they are a nutritious handy-dandy snack for some things.

Is it true that the Louisville area may get the cicadas worse than other areas? I think I read that. I mean we’re already a place with one of the worst allergy seasons, like what other unholy conditions have led to this possibility if that’s true?

So, Louisville is on the Ohio River. We see these insects associated very commonly with river corridors because there’s a lot of trees along river corridors, and so they like those long-limbed tree species that get in those spots. So yes, Louisville is one of the spots we expect to see quite a few cicadas come out. In 2004, there were 16 counties thereabout that reported large cicada emergences for Brood X. In Kentucky, Jefferson County was one of them. If you look at the map of it, they’re all really kind of along the Ohio River and then sort of tailing down from other smaller river corridors from those counties.

So, am I overreacting? How much should I actually expect these bugs to interrupt my vaxxed girl summer, or my pet’s, or my plants’?

It’s not an overreaction. I mean everyone is allowed to feel the way they want to feel about bugs. That’s one of the things about humanity. So I won’t say that you’re overreacting, but they’re not going to do anything directly to you. They don’t bite people. They don’t sting people. They do attack some of our trees. The larger, more mature trees that have been in the landscape for some time, those trees we don’t really have to worry about. They like oaks and maples and a lot of fruit trees. They stay away from our evergreens and a few other species, but they do have about 80 different hosts that they’ll lay their eggs in, but they’ll avoid things like perennial flowers and annual plants, and they avoid a lot of our ag-crops, So, it’s not that they’re going to be a plague that confounds farmers and everything like that. The biggest issue I would say is the noise. So, male cicadas do sing in order to attract females, and then they sing a courtship song to her in order to mate. And if they are singing together — which is one of their behaviors in their species is this chorus where the males will all sing in a tree to try and bring females to that tree — it gets over 100 decibels. And that is the thing that most people complain about is just that it’s so loud. It doesn’t stop until they’ve mated and died. So that’s really what really kind of confounds most people is just the noise level that they have to contend with.

So, when can we expect these creatures? Like, are there any warning signs, or will I just wake up one day with one crawling on my face? 

They won’t be in your house, luckily. You will go to bed one night and then the next day it will start. You’ll start to hear them, you’ll start to see the shells on the trees. They’re usually emerging in a nocturnal pattern. A warning sign is actually the blooming of irises. So what we see is that irises tend to bloom at the same time that the soil, eight inches deep, has reached 64 degrees Fahrenheit, which is the temperature they need to know it’s time to emerge. So we have had these weird fluctuations in weather. Recently, we just had snow on the ground here in Lexington I don’t know about over there. So I think that we’re on track for probably the early part of May, like the beginning of May. Sometimes it happens at the end of April, but based on these weird cold snaps that we’ve had, I would guess, the beginning of May.

OK, and then how long will they torture us for? 

Six to eight weeks is how long they’ll be around. They have this staged emergence pattern so the early ones that come out are the ones that get eaten a bunch, and then everything gets sick of eating cicadas. And the ones that come out in late May, early June, they’re the ones that tend to get to mate and have successful broods that they put in the soil.

And is there anything else you could say to make me feel better about Brood X descending upon the land? 

I would say that this is a uniquely American experience. You don’t get to see this anywhere else in the world. Some people travel to this country in different years when there’s not a pandemic just to see this weird bug Mardi Gras, where all of these teenage insects sing their song and have sex in trees. It’s a wild and wacky time, and it’s beautiful, it’s kind of unique and almost poetic. They come out, they sing this big musical number, and they, it’s a celebration of life, and then they die. So I think it’s unique and weird. That’s one thing to say about it. I do know that it bothers some folks, but think about all the good it will do for some of the animals, and that it won’t last forever. It won’t happen for another 17 years and maybe by then you’ll live in Wyoming or something where it doesn’t occur. 

Thank you. That is reassuring. The only way to escape is to move. So, will you be happy at least. Will you be excited about these? 

I am super excited. So cicadas are one of my favorites insects. I love the annual cicadas, by and large, but the periodical ones they’re — I guess there’s something I associate with kind of the beginning of my interest in entomology. When I was in high school, the emergences [were] happening in 2004 in Indiana, where I’m from. And it was just amazing. It was something that was quite enthralling. And it was this power of entomology, this power of insects — the fact that they are able to do something so weird and wild like this — it was one of those things that kind of brought me into the fold. So, I am excited. I know that I’m one of the few people that gets excited about billions of bugs boiling up out of the ground. But, it’s weird. I hope that some people will at least go out to places like Big Bone Lick and a few others, where we’re expecting heavy emergences, and take a listen, take some pictures. And if they do that, they can upload their data to an app called Cicada Safari, which will help us to map the population in Kentucky and better understand where these insects still thrive in the state.

That’s good. When I am sitting at the pool in a beekeeper’s suit, I will think of you, and I’ll say, ‘At least Jonathan is happy right now.’”