The big cicada invasion of 2021 has already started in some parts of the eastern United States, and billions of these mysterious red-eyed insects known as Brood X will soon be digging their way out of the ground and flocking to trees in more than a dozen states.
The Brood X cicadas have been hiding underground for a very long time — 17 years, to be exact. And now that the soil is warming up, it’s almost time for them to emerge in huge numbers.
When and where will we see, and hear, these uniquely loud insects? Why do they make so much noise? Why do they stay underground for so many years? And will they pose a danger to our trees, flowers, vegetable gardens and dogs?
In case you didn’t study entomology and biological sciences in school, we’re here to answer those questions and more.
Where will Brood X cicadas emerge in the U.S.?
This cicada map shows the 15 states that are most likely to see big numbers of Brood X cicadas in May and June 2021. The target zone stretches from Georgia in the southern U.S. all the way up to New York state and Michigan in the north.
Before you grab your camera and start searching for these bugs, be aware that not every region of each of these states will see the Brood X cicadas. Experts say they tend to stay close to the places where their previous generations emerged, reproduced and went into hiding during their earlier life cycles.
In general, if your town or city had lots of cicadas making a racket in 2004 or previous 17-year cycles, there’s a good chance you will see the 2021 brood.
Which towns in New Jersey will see the cicadas?
Experts say one of the hot spots in New Jersey will be the Princeton area of Mercer County, which had many documented sightings of Brood X cicadas during their earlier invasions dating all the way back to the early 1800s.
Other hot spots include Kingwood and Lambertville in Hunterdon County.
Check the map below showing the areas that are most likely to see the Brood X cicadas in May and June 2021. Also, check if your town is included in the detailed list in the link above.
When will the cicadas emerge?
During the first week of May, the Brood X cicadas have already started emerging from the ground in large numbers in parts of Maryland, Virginia and Tennessee, according to Gene Kritsky, an insect expert at Mount St. Joseph University in Ohio who has been studying cicadas for 45 years.
In recent days, some cicada nymphs and dime-sized cicada holes have been spotted in New Jersey, primarily in Princeton and Lawrence Township in Mercer County, Bloomsbury and Kingwood in Hunterdon and South Amboy in Middlesex.
That’s the first telltale sign that the bigger invasion is on the way.
“It’s not considered an emergence yet” until the insects start to come out in big numbers, climb into trees and shed their shells, Kritsky told NJ Advance Media on Thursday, May 6. But the early sightings of the nymphs and holes are significant.
“It’s proof that they are there,” Kritsky said. “It’s proof that there are (Brood X) cicadas in New Jersey, and we’re waiting for the other shoe to drop.”
When will the cicadas get bad?
The recent sightings in Virginia and Maryland are indications that a bigger “invasion” of these cicadas will likely occur in parts of New Jersey in the next one to two weeks, said Michael Raupp, an insect expert who teaches at the University of Maryland and is known as “The Bug Guy.”
“By the third or fourth week of May, that’s when you’re going to be swamped with cicada reports,” Raupp said. “A big tsunami is coming.”
Other entomologists believe the Brood X cicadas won’t be seen in huge numbers in the Garden State until early June and will likely reach their peak in mid-June. They say a big part of the timing is related to soil temperatures, which need to consistently reach 64 degrees before big hordes of cicadas crawl out of the ground.
Why are the cicadas so loud?
First things first. Only the male cicadas make all that noise, which is their way of attracting a mate so they can reproduce. While most humans find the racket annoying, bug experts refer to the noise as “singing” and note the three different species of Brood X cicadas each sing a different tune.
That’s their way of finding a female of the same species.
How loud do cicadas get?
Experts say the noise generated by large groups of cicadas can get as loud as 90 decibels — as loud as a gas-powered lawnmower.
But that’s how loud it will sound if you are standing directly under a tree where a lot of cicadas are “singing.” It won’t sound as loud if you are not standing close to the cicadas.
Will I see cicada shells all over my yard?
When the cicada nymphs crawl out of the ground, they quickly move to trees — and sometimes to other objects, like utility poles.
Once there, they shed their outer shell, usually within 90 minutes, and then turn a dark color.
“They have to climb up a vertical surface, lock their legs into place, and then shed their shell,” Kritsky noted. “I’ve seen them do it on tires, fences, brick walls, trees… even on big blades of grass.”
A new shell will form in about four or five days, Kritsky said, and then the cicadas start singing to attract their mates.
Where do the Brood X cicadas go for 17 years?
When the cicadas mate up in the trees, each female can produce as many as 500 eggs, which are deposited into small slits that the critters dig into thin tree branches.
“New nymphs hatch from the eggs, they crawl out of the nest and literally drop to the ground,” Kritsky noted. “As soon as they hit the ground, they crawl to a blade of grass, then start digging underground.”
The nymphs will feed on grass roots for several days, then spend 17 years underground feeding on the sap of tree roots.
Can you eat cicadas?
It may seem unappetizing to most people, but cicadas can be eaten by humans. In fact, the Washington Post says some chefs, bug experts and “insect-curious folks are prepared to explore the culinary possibilities” during the 2021 cicada invasion.
If you don’t think it’s so gross, check out the details in the link above.
Will cicadas damage my plants and trees?
Most trees and shrubs, especially if they are healthy and well-established, should be fine if periodical cicadas like the Brood X variety converge on them, according to insect experts at the University of Connecticut.
Experts say young trees and unhealthy saplings are the most vulnerable to damage from cicadas, because the female cicadas dig small slits into thin branches to lay their eggs.
“Periodical cicadas can damage fruit trees or woody vines, in the same way that they damage young or delicate trees,” the UConn bug experts say.
Most likely, your annual flowers and perennials will be safe, because “cicadas have little interest in these plants — except if they are woody,” the UConn experts say. “You may see (newly emerged) cicadas sitting on such plants, or emerging on them, but they will soon move up into the trees.”
Bug experts at the University of Maryland say “cicadas are harmless to most plants,” including flowers and vegetable plants.
Do cicadas bite people or animals?
“No,” says the bug experts at UConn. “Cicadas don’t bite or sting defensively, and they are not toxic or poisonous.”
However, the folks at the Cicada Mania website say some cicadas may try to suck on your skin.
“Don’t worry, they aren’t vampires, nor are they malicious or angry — they’re just ignorant and think you’re a tree,” they advise. “Just remove the cicada from your person, and go about your business.”
Will dogs get sick if they eat cicadas?
“Sometimes dogs or cats will go crazy out there eating them, and they may eat so much that they regurgitate them,” said Amy Korman, an entomologist for the Penn State Cooperative Extension in Lehigh and Northampton counties in Pennsylvania. “But it won’t hurt them.”
Another bug expert said it’s possible some dogs that swallow too many cicadas could experience a blockage in their digestive system and they may need to get treatment at a vet.
But typically, dogs that are accustomed to eating stuff other than their regular pet food can handle a few cicadas. Pet owners, however, should keep a close eye on their pets if there are lots of cicadas around.
How can I report a cicada sighting?
There’s an app for everything. And that includes one that allows you to report sightings of Brood X cicadas, and submit photos to document your findings.
The free mobile app — called Cicada Safari — was designed by insect researchers from Mount St. Joseph University, who say the public reports will help them in their research on periodical cicadas and the areas where they appear.
As of early Thursday, May 6, the app had been downloaded by 82,000 people, according to Kritsky, the university bug expert.
“We expected forty-five or fifty thousand people to sign up. We may end up getting over a hundred thousand,” Kritsky told NJ Advance Media. “It’s fantastic because it’s giving us lots of data that we were hoping to get.”
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Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com.
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