Now that the solar eclipse in Illinois is behind us, it’s time to look forward to the next rare phenomenon of 2024: cicadas.
Experts say 13-year-old cicadas and 17-year-old cicadas – also known as Brood XIX and Brood XIII – will soon surface at the same time in Illinois. This unusual and synchronized emergence is expected to bring “billions” of cicadas to the state.
“We are in the center of the explosion this year,” said Allen Lawrance, associate curator of entomology at the Peggy Notebaert Nature Museum in Chicago. “It’s quite rare to have two broods – one of 17-year-old cicadas, one of 13-year-old cicadas – emerging at the same time in an area where they overlap a little bit.”
Brood XIX will emerge “all over northern Illinois,” while Brood XIII will be in the southern part of the state, Lawrance said, with some parts of the state seeing both.
And they should arrive sooner than expected.
When will the cicadas appear?
Cicadas typically emerge in mid-to-late May and into June, when the ground begins to warm in spring and early summer. A National Weather Service article states that emergence can often depend on soil temperature.
“Research shows that the night at which periodical cicadas emerge depends on soil temperature,” the post reads. “Juvenile cicadas, or nymphs, emerge after a rainstorm when soil temperatures 8 inches deep exceed about 64°F.”
Climatic vagaries can also affect timing and emergence. According to the NWS, climate change impacting the emergence of a cicada occurred in 2017, when Washington DC experienced “a partial emergence of Brood X four years earlier.”
In theory, warmer temperatures in Illinois before summer could lead to earlier emergence, but “we’ll have to wait and see,” Lawrance said.
“Insects are cold-blooded,” he said. “They grow faster when it’s warm and slower when it’s cold.”
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Chicago officials issued an advisory last week, saying the first emergence is expected between late April and early June, but that the city may not see as much impact.
This means an emergence is likely between mid-May and early June, although some could begin as early as late April.
For the Chicago area, Brood XIII will be most visible in parts of northern Illinois and Indiana, and perhaps even Wisconsin and Ohio, in late May 2024, said Dr. Gene Kritsky, dean of behavioral and natural sciences at Mount St. Joseph University in Cincinnati said in a 2023 press release.
According to an article from the University of Illinois Urbana-Champaign Extension, emergence of the northern Illinois brood typically occurs in May and June and lasts about four weeks.
“Adult cicadas will be active until mid- to late June, but you will see evidence of them long after they are gone, including their wings, molts and decomposing bodies,” said Catherine Dana, an expert in cicadas. cicadas and affiliated with the Illinois Natural History Survey. told NBC Chicago.
Where will we see the two broods?
The Northern Illinois Brood, or Brood XIII, will be most visible in parts of northern Illinois and Indiana, and perhaps even in Wisconsin, Iowa and parts of Ohio . According to experts, this brood will be the largest in the Chicago area for the next emergence. But the distribution will be unequal.
“Not every neighborhood is going to be as dense as others,” he said. “One area might be slightly quieter and you’ll hear them in the distance. And then you go to the next neighborhood, and it’s jumping, and they’re everywhere.”
There is, however, one determining factor: if they were there before, they will be there again.
“So the neighborhoods you expect to find them in will depend on where they were the last time they appeared,” Lawrance said. “If the ground had been completely dug up and replaced because of construction, there might be fewer cicadas. But if they were there last time, there’s a good chance they would still be there.”
Meanwhile, Brood XIX, or Great Southern Brood cicadas, have a more widespread population, covering parts of Missouri, Illinois, Louisiana, North Carolina, Virginia, and Maryland.
“Brood in Oklahoma,” reports the University of Connecticut. “Although 13-year-old cicadas are generally considered to have a southern distribution, the northernmost known record of this brood is in Chebanse, Illinois, approximately 75 miles from Chicago’s Loop.”
Although the two broods have different regions of emergence, there could be overlap of the two in some places.
“Somewhere in central Illinois, probably like around Springfield, some researchers are predicting that we might see some overlap of these two different broods,” Dana said. “It won’t be a big area. But there will probably be some mating between these two broods, which will be really exciting.”
What do cicadas do underground?
For the past 17 years, billions of Brood XIX cicadas have lived underground, drawing on fluid from plant roots, Lawrance said. Once they emerge, they will be there for four to six weeks, Lawrance added.
However, how and when they emerge in such a harmonious manner remains a bit of a puzzle.
“It’s a big mystery,” Lawrance said. “How are they so synchronized to do this? At the same time? There seems to be something that is genetically or physiologically controlled, so they instinctively know to do this.”
And once they dig, there’s “really no escaping from them,” Lawrance said, especially on and around trees, where “heaps” of shells can be expected of cicadas after the insects have feasted on the liquid from branches and woody shrubs.
“You’re just going to see them flying around, hanging out in the trees, and you’re going to hear them everywhere you go,” Lawrance said.
That is, until they die and are composted into the soil. Or get eaten.
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“Everyone eats them,” Lawrance said. “The ‘life strategy’ of periodical cicadas is to emerge all at once. Anything that eats them can eat as many as it wants, and there are still more than enough cicadas left to maintain the population.”
Periodical cicadas, Lawrance said, are a “tasty little snack” for squirrels, birds or snakes. Dogs can eat them too, Lawrance added, in moderation.
“As far as insects go, they are very big and fleshy,” Lawrance said. “They have a lot of nutrients in them.”
What exactly are we supposed to do with it?
Not much, Lawrance said.
“You definitely shouldn’t try to remove them from an area that has billions of them,” he said, adding that they themselves will be composted into the soil.
“That’s kind of the important role that they play within our ecosystems: They spend a lot of time concentrating nutrients from a very good food resource of xylem and plants,” Lawrance said. . “And then when they emerge en masse, they return those nutrients to the soil in one big group.”
These nutrients could lead to a “large increase” in plant growth over the next two years, Lawrance added.
“Any animals that are there when they emerge will be very full and happy,” Lawrance said. “Plants are going to get a little boost in fertilizer…when we have extreme weather events, like a drought, the emergence of cicadas happens at just the right time and can provide a really valuable food source when nutrients are very rare.”
According to Lawrance, these nutrients could also be used in home gardens.
“If you want to fertilize your garden or save fertilizer for your garden, you can just throw a few piles of cicadas in there while they decompose,” Lawrance said.
“There is no way to stop them”
According to the Environmental Protection Agency, pesticides are “generally ineffective in repelling cicadas.”
“So many cicadas emerge at the same time that others will inevitably move in,” the agency said. “Spraying also doesn’t make sense because cicadas are generally harmless. Applying pesticides to control cicadas can harm other organisms, including animals that eat cicadas.”
With such large numbers, there will be nowhere to go in June, Lawrance stressed.
“There’s no way to stop them. They’re here. It’s temporary, and there’s really no way to escape them,” he said.
NBC Chicago
