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Two generations of periodical cicadas are emerging simultaneously for the first time in 221 years.
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Generations XIII and XIX overlap in a small portion of Illinois, around Chicago.
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People can help scientists track these insects using citizen science apps.
2024 is the year of the cicada apocalypse.
This is because two generations of periodical cicadas, generations XIII and Generation XIX, will emerge from their underground lairs simultaneously for the first time in 221 years.
The last time the two generations came together, Lewis and Clark began their journey through newly acquired territories through the Louisiana Purchase, the United States Supreme Court heard the landmark case Marbury v. Madison and Thomas Jefferson was president.
The hype over red-eyed insects has increased reached social networkswhere commentators are dismayed and excited about possible encounters with dual cicada swarms.
“In what sign of the apocalypse do we find ourselves again?” joked one Instagram user.
“Leap year, cicadas and an election year? I don’t know if I can do it,” said one commenter on Instagram.
Fortunately for those preparing to spend spring in their basement, the two generations of periodical cicadas won’t overlap – much.
Brood XIX will appear predominantly in the southern states, while Brood XIII will appear in a small section of the Midwest, primarily Illinois.
A portion of Illinois will see an overlap. That’s where cicada hunter Gene Kritsky and his wife Jessee Smith will head this year, along with many other cicada sites, to map his appearances.
“I’ve been mapping cicadas since 1976. I’m that old,” Kritsky told Business Insider. “I’m going to the Chicago region (I’ll be there the first weekend in June), where I’ll give lectures and do some hiking in the Lake County Reservation Area.”
Kritsky, an author, professor at Mount St. Joseph University and creator of Cicada Safari, an app that collects photos of cicadas for scientific research, is excited to see cicadas again this year after last year’s lapses. However, he is well aware of how polarizing the bug can be, both on and offline.
This is because they appear in their thousands, make a lot of noise, and their crushed remains can even pose a danger to drivers by making roads slippery. Sometimes they can damage young trees by trying to lay eggs on them.
However, cicadas are harmless and do not harm people or animals.
“I’ve helped people plan vacations to where the cicadas are emerging,” Kritsky said. “I’ve helped people plan vacations to be outside of where they’re emerging. So there’s both extremes to that.”
Unlike annual cicadas, periodical cicadas spend years in their underground quarters as brooding adolescents (is that why they are called hatchlings?) in 13- or 17-year cycles. In the case of the next two emerging broods, Brood XIII emerges every 17 years, while Brood XIX emerges every 13 years.
There are 15 calves in the US: 12 are 17-year-old calves and three are 13-year-old calves. Kritsky said this means there have been other cases of two generations appearing simultaneously in more recent history.
“In 1998, we had a 17-year-old calf and a 13-year-old calf,” Kritsky said. “So this happens. It happened probably 12 times, at least, in the last 200 years.”
That doesn’t mean, however, that periodical cicadas, which emerge by the millions, aren’t a sight to see.
The life of a periodical cicada.
Periodical cicadas, a red-eyed insect with a black body and orange rings, spend most of their lives a few centimeters below the ground, under trees. It’s a little cold at that depth, about 56 degrees Fahrenheit, so they don’t move much. Cicada nymphs make tunnels and live on the sap of tree roots. Kritsky told BI that many live near parks and cemeteries in suburban areas because they are attracted to “mature trees, full sun, low vegetation.”
This is their life for 13 to 17 years until it is time to reproduce. Scientists don’t know exactly how they determine how many years have passed, but evidence shows that they track the seasons by detecting the flow of sap in trees.
When the time comes, they emerge in late spring, when soil temperatures reach about 65 degrees. This happens at different times and in different places, between the end of April and the beginning of June. Depending on temperatures, Kritsky said Brood XIII could appear in early June or late May. The XIX calf, also known as the Great Southern calf, could appear as early as April.
Cicadas usually appear for the first time at night. The males will go out during the first few days, climbing the trees, and the females will follow later. The first days of freedom consist of shedding their old exoskeleton and hardening their new exoskeleton to become fully grown adults. Then it’s time to mate.
To attract a mate, male cicadas use an organ on their body that creates a sound similar to a high-pitched buzz. This may be what people recognize most about cicadas because they can make a lot of noise, like running a loud lawnmower.
If a female participates in the call, they mate. The female then searches for trees in brighter areas, locates tiny twigs at the end of the branches, cuts them off, and lays between 400 and 600 eggs. If they run out of space on one twig, they will fly to another, Kritsky said.
Once they complete their mission, the adult cicadas soon die. In about six weeks, the eggs hatch from the trees, fall to the ground and are buried to begin the cycle again.
Crowdsourcing has changed the game for cicadas
Before the existence of Cicada Safari, Kritsky said the largest number of cicada records was about 8,000 records of cicada locations. His research teams have received more than half a million records since 2019, thanks to thousands of cicada enthusiasts who submitted photographs. Kritsky said he has helped cicada scientists more accurately understand the distribution of periodical cicadas.
“We found records from areas where cicadas had never been reported before, not because they weren’t there, but because no one knew who to report them to,” Kritsky said.
The app has also helped researchers detect new patterns of emergence. Typically, smaller swaths of periodical cicadas emerge four years earlier, in a phenomenon scientists are still trying to uncover. However, more recently, scientists have noted that cicadas emerged a year earlier.
In 2023, researchers like Kritsky were able to record these patterns, which may indicate changes induced by climate change, thanks to observations by citizen scientists.
But more than that, the app, Kritsky said, has encouraged people to connect with family and friends through cicadas.
“You can mark your life by the appearance of cicadas that you have remembered,” Kritsky said.
Read the original article on Business Insider
