Billions of cicadas will emerge this spring. What does that mean in Florida?

Cicadas, the winged, red-eyed critters you hear chirping outside your window on hot summer days, are going to be even more abundant this year.

Researchers are predicting a rare cicada emergence that will culminate in billions of bugs leaving their cocoon-like shells for trees and grasses across the Southeast. Two generations — or what scientists call broods — of cicadas will emerge together at the same time and in close proximity for the first time in more than 200 years.

Brian Stucky, a biologist with the U.S. Department of Agriculture, has spent years studying the insects while stationed in Gainesville.

He says people in Georgia and Alabama won’t be able to escape cicadas’ incessant mating calls. But Florida, which sits just outside of the range for these two emerging broods, should be more quiet than neighboring states.

The Tampa Bay Times recently spoke with Stucky about the once-in-a-lifetime natural phenomenon and what Floridians should expect come May.

This conversation has been lightly edited for clarity and length.

Tell us about the life of a cicada.

The basic cicada life cycle is the female cicada will lay her eggs into the branch of a plant. And then those eggs will hatch these little, tiny baby cicadas — nymphs. They just drop down to the ground and the first thing they do is they burrow down into the ground and they look for a root that they can feed off of.

And then they’ll spend all of their developing years underground feeding on the roots of plants. And something that’s rather unusual among insects is that cicadas tend to have really long life cycles.

Most insects are relatively short lived. Oftentimes, an insect species will complete their life cycles in less than a year, but cicadas typically will live for many years. The vast majority of that time is spent underground while the cicadas are developing.

Then the nymphs will crawl out of the ground, and then typically crawl up the trunk of a tree or stem of a plant or — if it’s in an urban area — will crawl up fence posts or the sides of houses. People are familiar with the little shells that you can find on trees sometimes where the the adult cicada emerges and then eventually is able to fly off and complete its lifecycle.

As adults, basically all they’re focused on is finding a mate. If they’re females laying their eggs, then the adults die that same summer and then the life cycle starts over.

What are some misconceptions about these bugs?

People tend to be kind of scared of cicadas because they’re big insects. They look sort of ominous or kind of threatening, but they are actually completely harmless.

They don’t bite, they don’t attack, they don’t sting. As adults, all that they’re focused on is trying to find each other.

And something else I’ll mention that I think people are confused about sometimes: At least in Florida, you don’t often see cicadas because the species that we have, most of them are up in trees all the time. You can hear them all summer long, but people rarely see them. And there’s a bunch of other insects that live up in the trees that make noises, too.

There’s various species of katydids in Florida. And there’s the one species in particular — the true katydid — that calls in loud choruses, night after night for a good part of the summer. A lot of times, if it’s at night, typically what you’re hearing would be katydids and not cicadas. Cicadas are generally active during the day or maybe at dusk because it’s starting to get dark. But then by night, cicadas typically are no longer active.

What is significant about a cicada emergence like the one coming this year?

So what we haven’t talked about is there’s a group of seven cicada species — they’re all in the same genus that are called periodical cicadas. And those are the species that people are talking about for this spring. And what makes them unique is that all of the individuals within a certain geographic area will emerge at the same time every 13 or 17 years.

It’s one of these really spectacular natural phenomena because you have basically the entire population, emerging above ground every 17 years. The density of cicadas is incredible during an emergence here. It’s been estimated at over a million per acre.

As you can imagine, it can be extremely loud. There’s just cicadas everywhere. It’s an amazing thing. I think everybody should try to see it at least once in their life because it’s one of the most amazing natural phenomena.

Typically, the 13-year species and the 17-year species don’t usually emerge at the same time because those are both prime numbers. For a given 13-year brood, and a 17-year brood, that pair would only emerge at the same time every 221 years. So, that’s pretty rare.

And 2024 is a year in which a 13-year brood and a 17-year brood are emerging at the same time.

There’s actually a possibility that 17-year and 13-year species could interact with each other as adults, which is something that doesn’t happen typically. And there’s a chance that they could actually mate with each other and produce some kind of hybrid offspring.

If you are in an area where periodical cicadas are emerging, you absolutely cannot miss it. Because you will see them everywhere. You will hear them all day long. It’s incredibly loud. The males will typically form choruses. So they will kind of aggregate together and in trees.

If you find one of those chorusing centers, it’s extremely loud.

But Florida is outside that projected range, right? What should we expect to see (and hear) in our state?

As far as we know, there are no periodical cicada species that occur in Florida. They don’t seem to occur this far south. Intriguingly, there is some historical evidence from quite a long time ago that maybe there used to be periodical cicadas in the Panhandle of Florida, like a very small area. But they have not been re-observed there in many years. So as far as we know, there are none there.

They’ll be in Georgia. They’ll be in Alabama. And so if folks want to see it, depending upon where you live in Florida, you might not have to drive too far north.

In Florida, we have about 16 species of cicada. But we don’t have any of the periodical cicada species. The species that we have in Florida are sometimes called annual cicada species. And that’s because we see adults every year. They’re not synchronized like every 13 or 17 years. We have some adults of every species every year.

But the annual cicada name is a bit misleading because that makes it sound like they have a one-year life cycle. But that’s almost certainly not true.

For most of the Florida species, we don’t know what their life cycle is. But it’s a very good guess that it’s multiple years. We just don’t know how long.

Why is it that we don’t know all that much about Florida’s cicadas?

I think we have a good idea of which species occur in Florida. That number would be 16, as far as we currently know. But, yeah, for most of these species, we really don’t know a whole lot about their life cycle.

They live underground most of their lifetime. Their life cycles are long, which is not very conducive to laboratory research. They’re difficult animals to study.

Do you feel like there is a lack of research on cicadas in the state?

I think that’s fair. There haven’t been a lot of people that have really focused on them — trying to understand more about their biology and natural history. I think that’s absolutely true.

I think people are often surprised by how much we actually don’t know about most insect species. I think sometimes there’s this perception that we’ve kind of discovered things that are to be discovered about the natural world and animals.

But for groups like insects, there’s a lot more we don’t know than what we do, actually. And cicadas are part of that.