Rare dual emergence of cicadas has some people buzzing: ‘We think it’s a big deal’

The main event is a few months away, but ecologists, educators and others in northern Illinois are busy preparing for their own big game of sorts – the pending emergence of billions of 17-year periodical cicadas.

Throughout the region, special exhibitions, educational programs, events and activities are planned for the arrival – likely in late May and lasting for several weeks – of what is known as Brood XIII and the unmistakable drone of male cicadas calling for mates.

Adding to the buzz of anticipation is the rarity of having 13-year (Brood XIX) and 17-year cicadas emerge simultaneously for the first time in Illinois since 1803, when Thomas Jefferson was president and the Louisiana Purchase was finalized.

The next time this will happen is 2245.

Periodical cicadas are different from annual or “dog day” cicadas that emerge in July or August each year, as they spend 13 or 17 years underground developing. The nymphs of annual cicadas stay underground two to five years.

The dual emergence of the two periodical broods likely won’t overlap, experts said, but there is a small chance. Thirteen-year cicadas will cover most of central and southern Illinois, with a transition area south of Kankakee if traveling on Interstate 57.

In any case, there will be ample opportunities to get a close look at the life cycle of an insect that spends almost all of its life underground and emerges only to reproduce and die.

Nonetheless, cicadas are considered an important part of the ecosystem as a protein-rich food for birds and other predators and by providing nitrogen to the soil as their bodies decay.

With striking red eyes, a dark body and orange-veined wings, the 1½-inch-long insects are loud – and not the most attractive winged creatures. But they don’t sting, bite or spread disease. Like them or not, these curiosities of nature are a spectacle and rare educational opportunity.

“I’ve heard people describe this as the Super Bowl for cicadas, but that doesn’t even seem like a grand enough term,” said Brett Peto, environmental communications specialist with the Lake County Forest Preserve District.

“We think it’s a big deal,” said Nina Baki, a naturalist who serves as public engagement and program manager for the Forest Preserve District of Cook County. “Staff is looking forward to and planning for the emergence and encourages the public to enjoy it.

“I hope people see this as a really interesting exciting year.”

The Forest Preserve District of DuPage County also is readying a variety of educational programs and content to coincide with the arrival.

“This is an exciting and rare experience that should draw the attention of both bug enthusiasts as well as everyday outdoor visitors,” said Matt Mulligan, an ecologist with the Forest Preserve District of DuPage County.

Gene Kritsky, a leading cicada expert and professor emeritus of biology at Mount St. Joseph University in Cincinnati, said he already has fielded several media inquiries.

“Usually, these things start up in the middle of April,” he said of the attention to the topic. “I’m not complaining.”

Kritsky just released “A Tale of Two Broods: The 2024 Emergence of Periodical Cicada Broods XIII and XIX.” He visited Lake County for the 2007 emergence and will be back in June to sign books and as a featured presenter at several programs.

His website, cicadasafari.org, features a wealth of information and allows visitors to submit photos and track the cicadas’ progress in real time. Cicadamania.com is another resource.

“All I want people to do is just enjoy cicadas,” he said. “It’s like having a [broadcaster and biologist] David Attenborough special in your backyard.”

Kritsky said a brood is “like a graduating class that has a reunion every 17 years.”

Cicadas need stands of large mature trees that are available in forest preserves, parks and some neighborhoods to survive, Peto said.

The highest density will be in the eastern half of Lake County, where there are large, well-established oak woodlands, he said.

When the top 8 inches of soil reaches 64 degrees, the nymphs that have been drinking sap from tree roots for 17 years will dig their way out and climb onto trees for their final molt.

“I think of it as a diver pulling themselves out of a wet suit,” Peto said.

They are mostly white while drying out for about 90 minutes. Then, the mating calls begin. Eggs are laid in grooves in tree branches, hatch in six to eight weeks, fall to the ground and burrow in for the next 17 years.

Nancy Kuhajda, program coordinator at the University of Illinois Extension office in Will County, said it’s impossible to predict how the cicadas will affect the Will County area.

“With this mild winter followed with [a] cold spot, we can’t accurately predict the quantity – or how many – you will have,” Kuhajda said.

Cicadas do drop to the ground. So if you had them in the past, you may have them again, Kuhajda said.

How badly? Nobody knows, she said.

“I understand that, for most people, it’s really unpleasant,” Kuhajda said. “But it’s a natural phenomenon and relatively brief – about a month.”

There is no way to prevent or control the cicadas, Kuhajda said, but the cicadas also are not harmful, and there are benefits.

“They are food for birds and other animals,” Kuhajda said. “Also, during the time they spend underground, they are aerating our lawns and increasing water flow in our heavy clay soil.”

Nevertheless, residents with young sapling trees – or trees with few or small branches – should cover them with netting for the four weeks the cicadas are out, Kuhajda said. That protects the branches from cicada egg laying, she said.

“[For] natural areas like parks and preserves, just let nature take its course,” Kuhajda said. “But in the home landscape, we want to best know how to manage the issue.”

Denise Baran-Unland contributed to this story.

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