“One of the craziest life cycles”: billions of American cicadas will emerge

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“One of the craziest life cycles”: billions of American cicadas will emerge


In 15 states in the United States, billions of bugs will emerge soon after 17 years underground, scientists said, a sign that despite climate change, nature continues.
Two of those scientists working in the east coast state of Maryland, sift through a shovel laden with soil in a suburban backyard, Michael Raupp and Paula Shrewsbury to find their career: a cicada nymph.

In perhaps a third of a square foot of land, entomologists at the University of Maryland find at least seven cicadas – a rate of just under a million per acre. A neighboring court gave a rate closer to 1.5 million.

In a matter of days, a few weeks at most, Brood X’s cicadas (the X is the Roman numeral for 10) will emerge after 17 years underground. There are many broods of periodic cicadas that appear on rigid schedules depending on the year, but this is one of the largest and most noticeable. They will be in 15 states from Indiana to Georgia to New York; they are now coming out en masse in Tennessee and North Carolina.

When the whole brood emerges, the backyards can look like rippling waves and the chorus of insects is loud from the lawn mower.

Cicadas will come out most of the time at dusk to try to avoid anything that wants to eat them, squirming through holes in the ground. They will try to climb trees or anything vertical including Raupp and Shrewsbury. Once on the ground, they shed their skin and attempt to survive this vulnerable stage before becoming the dinner party for a host of creatures, including ants, birds, dogs, and cats.

Billions of cicadas are expected to emerge in 15 U.S. states in the coming days and weeks [Carolyn Kaster/AP Photo]

It’s one of nature’s strangest events, featuring sex, a race against death, evolution, and what can sound like a bad sci-fi movie soundtrack.

Some people can be pushed back. Psychiatrists are calling entomologists worried about their patients, Shrewsbury said. But scientists say Brood X’s arrival is a sign that despite pollution, climate change and the dramatic loss of biodiversity, something is wrong with nature. And that’s quite a spectacle.

Raupp presents the story of the life of the cicada with all the verve of a Hollywood blockbuster.

“You have a creature that spends 17 years in a COVID-like existence, isolated underground sucking sap from plants, right? In the 17th year, these teens will come out of the earth by billions, if not billions. They’re going to try best whatever wants to eat them on the planet during this critical time of the night when they’re just trying to grow taller, they’re just trying to be adults, get rid of that skin, get their wings, climb into the treetops, escape their predators, ”he says.

“Once you’re in the treetops, hey, it’s all about romance.” It is only the males who sing. It’s gonna be a big boy band up there as the men try to woo these women, try to convince that special someone that she should be the mother of his nymphs. He will play, sing songs. If she likes it, she’ll snap her wings. They’re going to have wild sex in the treetops.

“Then she will move to the small branches, lay their eggs. Then it will all be over in a few weeks. They will collapse. They will essentially fertilize the very plants from which they were spawned. Six weeks later, the tiny nymphs will fall 80 feet from the treetops, bounce twice, burrow into the ground, return underground for another 17 years.

A cicada nymph is sitting on the ground; they emerge in large numbers partly as a survival strategy – not all predators can eat them [Carolyn Kaster/AP Photo]

“This,” says Raupp, “is one of the craziest life cycles of any creature on the planet. “

The United States is the only place in the world that has periodic cicadas that stay underground for 13 or 17 years, says entomologist John Cooley of the University of Connecticut.

Insects do not appear in large numbers until the soil temperature reaches 64 degrees Fahrenheit (17.8 degrees Celsius). This is happening earlier in the calendar in recent years due to climate change, says entomologist Gene Kritsky. Before 1950, they appeared at the end of May; now they are coming out weeks earlier.

Although there have been a few early insects in Maryland and Ohio, soil temperatures have been in the high 60s Fahrenheit. So Raupp and other scientists believe the great emergence is a few days away – a week or two, at most.

Cicadas that come out early do not survive. They are quickly eaten by predators. Cicadas have developed a key survival technique: overwhelming numbers. There are just too many of them to all eat when they all emerge at once, so some will survive and reproduce, Raupp says.

It is not an invasion. The cicadas are here all the time, quietly feeding on tree roots underground, not asleep, slowly moving around waiting for their body clocks to tell them it’s time to come out and breed. They have been in America for millions of years, much longer than people.

When they emerge, it gets loud – 105 decibels, like “a singles bar has gone horribly wrong,” Cooley says. There are three distinct species of cicadas and each has its own mating song.

Highest concentrations of cicadas expected in Washington, DC area in May 2021 [ File: Jim Lo Scalzo/EPA-EFE]

They are not locusts and the only plants they damage are young trees, which can be harvested. The year after a big batch of cicadas, the trees fare better because the dead bugs serve as fertilizer, Kritsky says.

People tend to be afraid of bad bugs, says University of Illinois entomologist May Berenbaum. The mosquito kills more people than any other animal because of malaria and other diseases. Still, some people really dread the emergence of the cicada, she said.

“I think it’s the fact that they’re a downside. Plus, when they die en masse, they smell bad, ”says Berenbaum. “They really disrupt our sense of order.”

But others love cicadas – and even munch on them, using recipes like those in a University of Maryland cookbook. And for scientists like Cooley, there is real beauty in their life cycle.

“It’s a story of well-being, my friends. It really is and we need more of it in a year, ”he says. “When they come out, it’s a good sign that the forests are in good condition. Everything is as it is supposed to be.



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