Cicada Mania 2024: Billions To Emerge In Rare Double-Brood Event
A rare — and, depending on your outlook, potentially horrifying — event is about to take place throughout the American Midwest and Southeast. How unusual? Well, the last time this situation occurred, the year was 1803 and Thomas Jefferson was President. Basically, the region is set to be absolutely overwhelmed by what some have dubbed an “insect apocalypse.” Billions, potentially trillions, of cicadas are going to emerge from the ground to wreak havoc.
A remarkable creature
Cicadas are remarkable creatures. There are some 3,000 species accounted for, all of which have big eyes, see-through wings, and bulky bodies. We can broadly split all the species into different categories: the annual cicadas and the periodical cicadas. We’ll get into the differences between the two shortly.
Cicadas can be easily confused with locusts, and, sure enough, there are similarities. They kind of look alike, for one thing, with both sets of insects having six legs, bodies that are segmented in a similar way, and big eyes.
Cicadas vs. locusts
The distinctions between cicadas and locusts are significant, though. They’re members of different orders, with cicadas being considered Hemiptera and locusts being classified as Orthoptera. The differences between these two groups are real, but perhaps the subtleties involved are for the entomologists to think about.
As for the rest of us, there’s a pretty clear divergence that we can note: cicadas don’t swarm, but locusts very much do. And when locusts swarm, they can consume huge amounts of vegetation, potentially leading to famine for human populations.
Covered in creepy-crawlies
For thousands of years, certain areas have been ravaged by swarms of locusts. Even in recent times — like in eastern Africa across 2019 and 2020 — the insects have devastated populations’ food supplies. As for cicadas, we’ll never see anything like that. They don’t travel across great distances, as locusts can.
While cicadas don’t swarm, they do emerge in tremendous numbers when it’s time to reproduce. If you get caught up in that, you’re liable to get covered in the creepy-crawlies!
Time spent underground
Annual and periodical cicadas differ in the length of time they spend underground at the start of their life cycle. Annual cicadas generally spend two years beneath the surface as nymphs, while their periodical counterparts will be underground for 13 or 17 years!
Of the 3,000 or so cicada species, a mere nine are classified as periodical, and seven of those are based in North America. The other two are in India and Fiji, respectively.
A strange way of life
The cicadas have a strange way of life, at least from the perspective of us humans. As such, the insects have long been a source of great interest to people, with many cultures around the world considering the insects’ life cycle to be symbolic of the notion of rebirth.
In ancient China, cicadas were a special focus of reverence. On the one hand, they represented the beginning of summer, as that’s when they emerged. But they also symbolized renewal and were considered models of leadership!
The most amazing racket
Many cicadas — though not all — are capable of making the most amazing racket. It can sound like a buzzing or clicking, though different species produce different sounds. At their loudest, certain species make noises equivalent in intensity to a roaring chainsaw!
A species in Africa has been known to hit 106.7 decibels, which is incredibly loud. Some people can find the noise extremely unsettling, but, on the plus side, any such din willl be over in a matter of weeks.
The broods
Given the strange nature of the periodical cicada’s life cycle, entomologists place them into groups known as “broods,” which are each assigned a Roman numeral to help distinguish them. This system helps the experts to keep track of the insects and to figure out when each group is set to emerge from underground.
Basically, all periodical cicadas that belong to the same life-cycle type — as in, those that emerge every 13 years and those that emerge every 17 years — and that emerge in the same year are classified as part of the same brood.
The math
Cicada broods aren’t defined by members being the same species — it’s all about the timing of their life cycle. There are 12 broods that experience a 17-year life cycle, while there are only three that emerge every 13 years.
Given the mathematics of it, most years will see the emergence of one brood in at least one specific place. This year is different, though: an unusual overlap is about to occur.
Illinois and Indiana are in for some noise
Brood XIII — which exhibits a 17-year cycle — and the 13-year Brood XIX are set to emerge from underground this year. This is extremely rare. The last time it happened was in 1803 and it won’t happen again for another couple of centuries! The broods’ respective cycles will next overlap again in 2245.
The real kicker is that Brood XIII and Brood XIX are actually located close to each other. Yep, people in parts of Illinois and Indiana are likely to experience the simultaneous emergence of both sets of cicadas! The noise is likely to be deafening!
The insect apocalypse?
Both broods look set to appear towards the end of April. Experts believe certain forested parts of Springfield, Illinois, are most liable to see both broods appearing at the same time. If you live there, you might want to book a vacation or something!
Certain quarters of the press have been describing this event as an “insect apocalypse.” That’s definitely an over-the-top way of putting it, but it can’t be denied that a certain amount of disruption can be expected.
The life cycle
Let’s take a deeper look at the periodical cicada life cycle, just to get an idea of what Illinois and Indiana residents can expect. A cicada’s life begins in an egg, which, after six to ten weeks, hatches. A nymph emerges and immediately begins to bore underground, where it feeds off liquids found in the roots of plants.
The nymph develops underground for either 13 or 17 years, before it molts and emerges from underground as an adult. It then mates, more eggs are laid, and the adults die.
The right conditions
The cycle relies on environmental conditions to be completed. The temperature of the soil is vital — it needs to thaw following the cold of winter and to ultimately hit 65°F. Then the cicadas can emerge to begin their mating frenzy.
As for the weird life cycle lengths of 13 and 17 years, scientists can’t be entirely sure of what’s going on. There are theories to account for it, though, and they’re intriguing.
Prime numbers
You may have noticed that 13 and 17 are prime numbers, but what’s the significance of that? Well, it means that potential predator species can’t easily synchronize their own life cycles with those of a specific brood of cicadas. That serves as a form of protection.
Another theory that tries to account for the prime number life cycles suggests that they serve to prevent members of different broods from mating. Evolution really is a remarkable thing.
An all-you-can-eat buffet
As for why cicadas emerge in such tremendous numbers, it’s thought that it’s also a defensive measure for the broods. The logic is that there are so many individual cicadas out and about that no predator could possibly eat them all.
That’s not for want of trying. There are plenty of creatures that do eat the cicadas when they emerge, including birds, wasps, spiders, and certain mammals. Cicada emergences are quite the all-you-can-eat buffet for them.
“Sitting ducks”
Martha Weiss, an insect expert from Georgetown University, explained the situation in more scientific terms. She said, “The whole point of the gigantic co-emergence is that they are synchronously coming out and satiating their predators. Because cicadas are hyperabundant, they are entirely undefended.”
“They are not poisonous, they’re not spiny, they’re entirely palatable, they are slow flyers — they really are just sitting ducks. Their defense is coming out in the billions. Predators really just can’t possibly eat all of them.”
The beginning
For anyone in Illinois or Indiana come the end of April, there’ll be indications that the mass cicada emergence from underground is about to begin. Look to the ground, and you’ll see little holes roughly the size of a person’s fingertip.
What’s happening is that the cicadas are digging their way out of their longtime underground homes. The “insect apocalypse” — if you’re minded to use that kind of hyperbole — is about to begin.
Shedding the exoskeleton
The wingless cicadas will get out of their holes as swiftly as possible, before rushing to the nearest vertical structure. It’ll likely be a tree, which they’ll climb and — this is the stuff of sci-fi — “shed their exoskeleton,” as BBC Science Focus put it.
For people in the area where this is happening, it means the ground will be littered with crunchy shells underfoot. The insects, meanwhile, will start using their wings for the first time. And now it’s about to get noisy.
The din
Near the center of the male cicada’s wings is an organ known as tympanic membrane. This is what produces the loud clicking sound that can reach such deafening levels. The noise is what attracts females to mate with them.
The females can also make a noise, too. They make it with their wings, and it all just adds to the din. This will go on for about six weeks, before the adults die off.
A feast
As unpleasant as this six-week-long noisy period can be for humans living in the area where it’s occurring, other animals can benefit hugely. Those that feed on the insects have essentially unlimited access to food, as Mike Raupp, a professor emeritus from the University of Maryland, explained to the BBC.
“Birds and small mammals will have a feast which will result in increased reproduction and survival of their offspring,” Raupp said. “From an evolutionary standpoint, it could be very interesting.”
Hundreds of eggs
Throughout the frenzy, the female cicadas will punch little holes into trees and shrubs. Into these holes they’ll lay their eggs, typically about 20. That’s just the start of it, though, as males and females will mate on many different occasions.
A female that survives throughout the whole six-period will lay something like 600 eggs in total. The numbers involved are difficult for us to comprehend: the lives of cicadas are just so different to mammals like us.
Nymphs emerge
When all their mating has been completed, the cicadas will die: their 13- or 17-year life cycle is over. The eggs, meanwhile, will remain in place for about six weeks, before they then hatch. The nymphs emerge and drop to ground level.
The nymphs, as their parents did before them, begin to bore into the ground. They feed off plant roots and remain down there for 13 or 17 years, depending on the brood.
A vital role in death
As for the remains of the dead adults, they still have an important purpose — aside from freaking out people on the surface who step on them, that is! They also serve to boost soil health; as they break down, nutrients enter the soil and plants thrive.
Experts have observed increased tree growth in areas that have hosted the phenomenon of a large-scale cicada emergence. It’s like fertilizer being laid in the area, and it’s vital to the ecosystem.
A macabre Mardi Gras
This particular event, in which Broods XIII and XIX will emerge at the same time, should conclude by the start of July. Only then will people living in affected areas experience calm: until that point, they’ll just have to grin and bear it.
Attempting to characterize the event, University of Kentucky entomologist Jonathan Larson told Smithsonian magazine, “It’s pretty much this big spectacular macabre Mardi Gras. It’s a lot of singing, lots of paramours pairing up, and then lots of dying.”
Excited entomologists
Entomologists are obviously fascinated by what’s about to occur. One such expert, Catherine Dana, told Scientific American, “I’ve been looking forward to this for years. We have two different broods emerging in the same state, and that’s a very rare thing.”
For citizens without a specific interest in insects, though, the prospect of the dual emergence isn’t quite so rosy. Normal life is set to be temporarily overturned in favor of this insect frenzy.
Not dangerous
The important thing to note about all this, though, is that cicadas aren’t dangerous. They can’t bite you, nor can they sting you. They won’t destroy crops or your garden plants: they’ll just make a lot of noise and leave a trail of exoskeletons and bodies in their wake.
The Environmental Protection Agency advises that people shouldn’t deploy pesticides to deal with cicadas. Given the sheer number of cicadas that emerge, there’s no way the chemicals would be able to manage the situation.
In and out
A lot of people are going to be moving in and out of Illinois and Indiana because of this rare dual cicada emergence. On the one hand, there’ll be locals who want nothing to do with this insect apocalypse who will desperately flee the area. While on the other hand there’ll be insect enthusiasts flooding into the region to see this once-in-a-lifetime occurrence for themselves.
Gene Kritsky, who wrote A Tale of Two Broods: The 2024 Emergence of Periodical Cicada Broods XIII and XIX, mentioned this to NBC News. “I’ve talked to half a dozen people already who want to go on vacation and come into the area to seek the cicadas,” he said. “In years past, I’ve also helped people plan vacations to leave while the cicadas are here.”
Dressing for the occasion
Locals who stay may want to dress for the occasion. Reports documenting previous cicada emergences have described people taking to the streets wearing beekeeping suits, which is a pretty good way of making it through the frenzy without hundreds of insects clinging to them.
Without access to something that sophisticated, other people have been forced to improvise protective outfits. Some have employed umbrellas and shower curtains to keep themselves insect-free: desperate times call for desperate measures!
An upsetting experience for some
Most people who experience the dual cicada emergence will make it through the six or so weeks it lasts okay. It’ll be an inconvenience, certainly, but not much more than that. This year is unusual, yes, but singular broods emerge most years, and the people who experience it are fine by the end of it. Some people, though, will be upset by it.
In 2021 The Guardian spoke to people who’d previously seen cicadas emerge. Michelle Dillingham was one such person, and she told the paper, “I was totally taken by surprise. It was so debilitating: sitting in my car, looking out the window, seeing these very large cicadas flying around and feeling frozen, like I could not move.”
A major fear
It’s estimated that 12.5 percent of adults in the United States suffer with a specific phobia at one point or another. Entomophobia, an aversion to insects, is an aversion that some people experience, and for such people, cicada season can be a nightmare.
For people with mild entomophobia, the emergence of cicadas is still pretty awful, even if their lives won’t be totally upturned. But for the people with severe versions of the condition, it can be a crippling experience.
“Not normal behavior”
The Guardian also spoke with someone called Ritter Hoy, who falls into the latter category of people. “Sure, it’s irrational,” she admitted, “a bug that comes out every 17 years, how does it affect your life? But it really does. It’s traumatic.”
Even the very nature of the cicada life cycle freaks Hoy out. “They just chill underground, for almost 20 years. I went to college in that time! That is not normal behavior.”
Impossibly difficult
Some people can find everyday life impossibly difficult when the cicadas are around. Maybe they’ll be unable to attend work, or to pick up their kids from school — it really can be disruptive for some.
That’s why Dillingham set up a Facebook group for people afraid of cicadas to seek support. Just over a month following its establishment, the group had welcomed nearly 1,000 people into its ranks, which just goes to show how many people are affected.
Grasping the insect
The group does appear to have helped some people to, if not totally overcome their phobia, then at least make progress towards managing it. One person posted to inform the other members that they had felt empowered enough to take an ailing cicada into their hand.
“Its legs were still kicking — but I held it,” this person posted. “I don’t want a bug to control me.” Not everyone has made such progress, though, with another person writing, “My home has become my prison.”
A nice meal
It must horrify the members of the phobia group, but there are people out there who find a good use for the swathes of cicadas: they eat them! After all, it’s a lot of protein that just appears from the ground one day. Why let it go to waste?
Cicadas can be deep-fried or sautéed, and they apparently taste kind of nutty. Just be mindful of the possibility of having a reaction: apparently people also allergic to seafood are especially prone.
Young trees may need protection
If you have young tree saplings in your garden, you may want to protect them. Older trees won’t suffer because of cicadas, but the young ones might be weakened. If you cover them with a mesh, they might be alright.
Older trees and any fruits and vegetables you might be growing should be okay by the end of all this. As previously mentioned, it’s not like a locust infestation, so there’s no need to panic on that front.
Mast years
Big trees are rarely killed by cicada damage, but their own life cycles can still be affected by the activities of the female insects. As they lay their eggs, certain trees can be damaged to the extent that “mast years” are instigated. That means they produce fewer seeds for two years.
At the end of those barren years, though, a new harvest will see a huge number of seeds being produced. It’s an amazing phenomenon that itself has a remarkable impact on ecosystems.
A strange, but vital, life cycle
Strange as it can be to think about, entire forests can be profoundly influenced by the life cycle of cicadas. As George Washington University’s John Lill pointed out to Scientific American, “[Periodical cicadas] were here long before people were.”
“They have a really strange life cycle, but they’re an intrinsic part of these forest ecosystems that have been here for millions of years.” Their behavior might seem bizarre to humans, but cicadas are vital to our world.
Changes to the cycle
Inevitably, the lives of cicadas are being affected by climate change. According to Kritsky, over the last 100 years or so they have started to emerge from their underground homes earlier than they used to. He added, “And there have been more broods emerging four years ahead of schedule.”
The continued destruction of woodlands is also a major problem for cicadas and the ecosystems that rely on them. Some broods have already gone extinct because of this, and it remains a concern.
Fun for bug geeks
But despite the ongoing concerns about the future of the cicadas, insect experts and enthusiasts will enjoy this coming dual-emergence event. As Raupp told the BBC, “There could be more noise, more fear for entomophobes, more fun for bug geeks like me. And yes, it is a wicked cool and interesting event that happens nowhere else on Earth.”
For anyone who isn’t actually terrified of cicadas, this is an event to treasure. It might be noisy and weird, but it’s a remarkable phenomenon that doesn’t come around very often.
A lifelong memory
Nobody alive today will ever get the opportunity to see Broods XIX and XII emerge at the same time again. The next overlap will take place in 2245, and, well, who knows what sort of state the world will be in by then? If you’re in a position to, this event should be appreciated.
As Catherine Dana told Scientific American, “Kids will remember this for their lifetime. Maybe they will remember it as being disgusting and loud, but it’s also, in a way, magical.”