(2024-03-28) The Earth Will Feast On Dead Cicadas

The Earth Will Feast on Dead Cicadas. Brace yourselves, Illinoisans: A truly shocking number of cicadas are about to live, make sweet love, and die in a tree near you. Two broods of periodical cicadas—Brood XIX on a 13-year cycle and Brood XIII on a 17-year cycle—are slated to emerge together in central Illinois this summer for the first time in over two centuries

To many other Midwestern animals, plants, and microbes, they’re a rare feast, bringing new life to forests long past their death.

From Nebraska to New York, 15 broods of periodical cicadas grow underground, quietly sipping watery sap from tree roots. After 13 or 17 years (depending on the brood), countless inch-long adults dig themselves out in sync

Cicadas don’t fly far from their birthplace, so each brood occupies a distinct patch of the US.

Most years, at least one of these 15 broods emerges

Sometimes two broods emerge at the same time. It’s also not unheard of for multiple broods to coexist in the same place.

During 2004’s Brood X emergence, Lill remembers walking outside at midnight. “For two seconds, I was like, ‘Wow, I didn’t know it was raining,’ because I saw water flowing down the street. As my eyes focused, I realized it was literally just thousands of cicadas crawling across the street.”

Cicadas are shockingly chill, protein-packed, and taste like high-end shrimp—easy, delicious prey. “Periodical cicadas are sitting ducks,” says Lill. They don’t bite, sting, or poison anyone, and they’re totally unbothered by being handled

Much like an unexpected free dinner will distract you from the leftovers sitting in your fridge, this summer’s cicada emergence will turn predators away from their usual prey. During the 2021 Brood X emergence, Zoe Getman-Pickering, a scientist in Lill’s research group, found that as birds swooped in on cicadas, caterpillar populations exploded. Spared from birds, caterpillars chomped on twice as many oak leaves as normal—and the chain of effects went on and on.

Once mating season winds down, so does the cicada’s life. “In late summer, everybody forgets about cicadas,” Lill says. “They all die. They all rot in the ground. And then they’re gone.” By late June, there will be millions of pounds of cicadas piling up at the base of trees, decomposing. The smell, Kritsky says, “is a sentient memory you will never forget—like rancid Limburger cheese.”

They may smell like bad hamburgers, but Yang says that if you’re lucky enough to host a tree full of cicadas this year, it’s best to just leave their bodies alone to decompose naturally

Researchers are clamoring for citizen scientists to send in photos of their local cicadas to help map the upcoming emergence. The Cicada Safari app, developed by Kritsky, received and verified 561,000 cicada pics during the 2021 Brood X emergence—he hopes to get even more this time around.

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