UNB biologist explains 'cicadapocalypse' hitting U.S. this year | CBC News (2024)

Raechel Huizinga · CBC News

· Posted: Mar 31, 2024 5:00 AM EDT | Last Updated: 5 hours ago

If you're in the United States this summer and see the earth crawling with hordes of insects, don't panic — this has been in the making for more than200 years.

This year, two broods of cicadas will emerge at the same time in parts of the U.S. After spending years in darkness, trillions of them will scurry out of the earth, mate furiously, hang out on some trees and die, all in the span of a few weeks.

"They're really handsome insects. They're kind of the size of your thumb," said Steve Heard, a biologist at the University of New Brunswick who studies interactions between plants and insects.

People usually hear cicadas more than they see them. For some, their low, buzzing whine is the emblem of summer, and if you spend time wandering through the forest during that season, you might come across their exoskeletons molted onto the bark of trees.

WATCH: See what it was like when just one brood emerged in 2013:

New Brunswick has cicadas, Heard said, but they come out every year, while the cicadas getting ready to party in the U.S.are periodical cicadas, meaning they spend long periods underground and emerge at specific intervals.

But why is this "cicadapocalypse,"as some scientists are calling it, happening in the year 2024? According to Heard, it has to do with math. One brood emerges from the earth every 13 years, the other every 17 years. Every 221 years, their schedules align in a stunning act of what Heard calls synchronized biology,and boom: cicadapocalypse.

The first cicadas will emerge sometime in April in southern U.S. states, such as Alabama, Heard said, and the rest will come out in the midwest and north, where it takes longer for the soil to thaw, throughout the summer. In terms of numbers, Heard predicts as many as one million cicadas per acre.

The 13-year brood will take over the south and the midwest, whereas the 17-year brood will emerge in the northern midwest, and there will only be a small overlap between them.Someone's backyard, or a small patch of woodland could have both broods.

"It's not like you're going to have twice as many cicadas in one spot, which would be spectacular," Heard said. "But it's already pretty spectacular."

While it would be a trek forinsect enthusiasts in New Brunswick to witness this phenomenon, Heard said there will be an abundance of social media posts documenting the cicadas. You might see images of exoskeletons piled up on trees three or four bodies deep, he said, or photos of the creatures on someone's hand, since they're not usually seen up close.

"When you do see one it's like,'Whoa, what is this thing?'" he said. "People get very excited about it. Sometimes scared, which they don't need to be, and sometimes excited because they're so cool."

Cicadas are not well-defended against predators, Heard said. They're not poisonous, and they don't fly well. Their survival method is one New Brunswickers might recognize in salmon. They produce an overwhelming amount of offspring so that at least some survive.

"No one could possibly eat them all," Heard said.

The primary reason cicadas spend so much time underground is their diet. Larvae tunnel underground after the mating season and only feed on watery sap from tree roots, so it takes a long time for them to mature.

Nature is complicated, Heard said, and the cicadapocalypse will have lotsof different impacts on the environment. The birds and small mammals that do eat cicadas will be very happy, he said, almost making cicadas unwilling martyrs for the creatures they usually eat.

"There's so many cicadas around that if you're a little caterpillar, maybe you escape," he said. "It's really fascinating to see how this cicada event is going to drive all these other effects."

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