The ground seemed to move at night, alive with bugs. After 17 years underground, crawling cicada nymphs marched in large numbers towards trees, climbing up and pausing to shed their skin and emerge as adults. And then the fun began.
Cicada chaos is thriving and flying. Trillions of once-hidden baby bugs are in the air, on the trees, and perching on people’s clothes and even faces. They have red eyes, are loud, and are frisky.
“What you saw was biblical,” said biologist Gene Kritsky, who has been chasing periodical cicadas for 50 years, yet was still amazed by the 3 to 5 million cicadas crowding a small patch of Ryerson Conservation Area north of Chicago. “There are things I’ve seen this time that I’ve never seen before.”
This spectacle only happens in the United States, and it’s the last of the triple crown of rare forecasted natural wonders.
First, there was the solar eclipse in April, followed by the Northern Lights unusually far south in May. Now the great dual periodical cicada emergence of 2024 — an event not seen since 1803 — has burst from below to join the earlier shows in the sky. It’s lasting weeks longer than the other two fleeting natural rarities, but in many places the cicada invasion is starting to wind down.
The males are singing for sex and won’t stop until they get a female cicada’s flapping wing consent. In some places in Illinois, the noise level hit 101 decibels, louder than a lawnmower. The sound flows in waves as an ever-present buzzing drone that seems like aliens descending in a science fiction movie. It is punctuated by bursts of the deeper-toned call “fffaaaro, fffaaaro.”
The sound is everywhere in the suburbs of Chicago, such as Oak Brook, but has already faded farther south in the state, including where two broods overlap. In a DuPage County shopping plaza with a lot of asphalt, cicadas mobbing the branches of the only tree drowned out the noise of the automated car wash’s whirring hoses and spinning brushes next door.
Cicada chasers in 18 Midwestern and Southern states have submitted photos of the bugs to the Cicada Safari app, mostly concentrated in two areas, each an emergence of different broods.
The Northern Illinois brood, called XIII and coming out every 17 years, is extra dense, with as much as 1.5 million bugs per tree-covered acre — which is nearly a billion per square mile — in some places like Ryerson, Kritsky said. The Great Southern Brood, which arrives every 13 years, stretches from Virginia to Missouri and southern Illinois to Georgia.
In Central Illinois, especially around Springfield, the two broods just about overlap. But it’s hard to tell which brood a cicada belongs to.
U.S. Department of Agriculture research entomologist Rebecca Schmidt said usually when she gets calls about bugs, it’s something bad and scary, like murder hornets. Periodical cicadas are different and “people are coming to us for good reasons, like ‘tell us more, we’re very excited, enthusiastic about this’,” she said.
“It’s a nice little gateway to these amazing things that the natural world does, some of which we can predict with a lot of accuracy,” Schmidt said.
They’re just weird, with powerful jaws and jets of urine and a zombie fungus that sometimes hits them.
Yet many people are scared or grossed out by the trillions of flying bugs that die soon after mating in a rather pungent pile on the ground.
The only possible danger is to young trees, mostly from when the females slit notches in branches to lay their eggs, Rydzewski said. So many newly planted trees sport white protective netting — a contrast to the black winged bugs lined up on some adult trees.
Overall, cicadas play an important role in the local ecosystem as fertilizer, aerating the soil and food for birds and other animals, said Marvin Lo, a tree root biologist at the Morton Arboretum. He picked up cicada carcasses from one area, ground them in his lab into a stinky powder to measure and test them later.
The Associated Press contributed to this article.