FAQ: What to Know as Brood X Cicadas Emerge in 15 States and DC

When will the 17-year cicadas arrive, and how long will they stay? Here are answers to your top questions

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Billions of cicadas are beginning to stir underground in D.C., Maryland and Virginia, and the first few are crawling up to begin a weekslong period of cacophonous mating.

While some may be worried about creepy crawlies, University of Maryland entomologist Michael J. Raupp encouraged people to get excited about this exceptional event.

“This is a unique, natural phenomenon that happens nowhere else on earth besides the eastern half of the United States,” Raupp said.

These cicadas breed and grow in 17-year cycles, so they haven’t been visible in the D.C. area since 2004 — and a lot of people are wondering what to expect.

Here are answers to the most common Brood X cicada questions.

With the end of the month drawing near and warmer weather over the past few days, we’re seeing a few “early rising” cicadas. Storm Team4 Meteorologist Amelia Draper reports.

When do the Brood X cicadas emerge in D.C., Maryland and Virginia?

Cicadas emerge when temperatures several inches underground reach about 64° in your neighborhood.

The first signs of cicadas emerging appeared in late April in areas including College Park, Maryland, and upper Northwest D.C. More will come out in the coming weeks.

Cicada season will likely be in full force in the capital region by the last two weeks of May, Raupp predicted. Each area’s timeline could vary depending on the temperature and other factors in different areas, but once you start seeing cicadas in your area, their numbers could explode overnight.

By the end of June, the swarm should be over.

How many Brood X cicadas are there?

Certainly billions, and likely trillions.

How do you pronounce "Brood X"?

There are 15 broods of cicadas found in the United States. The cicadas emerging in 2021 are Brood X, sometimes called the Great Eastern Brood.

The "X" in Brood X is the Roman numeral for 10, so you'd say "Brood Ten," not "Brood Ex."

Where are the Brood X cicadas?

Brood X covers the largest geographical area in the United States.

Brood X cicadas can be found in parts of Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and D.C.

You’ll see the highest number of cicadas in parks, nature preserves and neighborhoods that underwent less construction and development in the past several decades.

Brood X cicada map:

Brood X cicadas are found in parts of 15 states. The USDA Forest Service's map below shows Brood X territory shaded with yellow, or red with black stripes.

Brood x cicada map

Where won’t there be cicadas in D.C., Maryland and Virginia?

Southern Maryland doesn’t get periodical cicadas, and Brood X isn’t typically found in central, southern or western parts of Virginia.

You’re also not likely to see them in recently built-up neighborhoods such as Navy Yard.

What’s the cicada timeline?

Individual cicadas climb out of the ground, molt and then mature into adulthood over several days. Once adults, cicadas live three to four weeks.

The peak of cicadas singing, mating and laying eggs — and buzzing all around your neighborhood — typically happens within five weeks, according to Cicada Mania.

Memorial Day might be buggy, but by the Fourth of July this rare event should be over.

Signs of Brood X Cicadas Emerging: Look for These Clues

What are the signs of cicadas emerging?

There will be signs that cicada time has sprung — even before their legendarily loud mating songs begin.

The first indication that cicadas are emerging in your area would be dime-sized holes that go deep into the soil. Cicadas could stay in the holes for a while after digging them or climb up into trees.

After that, the signs will become harder to ignore. Expect to see a lot of empty, molted shells, even some that are left attached to vertical surfaces.

Then, you might need noise-canceling headphones to block out their songs.

What do Brood X cicadas look like?

There are three species of Brood X cicadas. They all have six legs, red-orange wings and legs, and most have large, red eyes — except for a few rare instances of blue eyes.

Magicicada septendecim are usually the first to emerge and the largest. Their undersides are orange.

Magicicada cassini are typically smaller and emerge shortly after the septendecim species. They have black bellies.

Magicicada septendecula are also small. Their undersides are orange and black.

What do Brood X cicadas sound like?

Loud. The chorus of mating calls can reach 100 decibels — louder than a lawnmower.

They’re making a huge racket to find their mates, and different species have distinct mating calls.

M. septendecula make a ticking noise; M. septendecim make a “wee-oh” sound that’s been compared to a spaceship, and M. cassini sound like static.

You may remember the beady red eyes, the translucent wings or the constant noise: Seventeen years after Brood X cicadas headed underground, they're coming for the D.C. area again. News4's Megan McGrath talks to an expert about what to expect.

Why do the Brood X cicadas come out every 17 years?

Cicadas emerge in massive numbers every 17 years to mate. That's right: The loud chorus of buzzy screeches is a love song.

Their long lifecycles and massive numbers are likely both survival mechanisms for the species. Predators don’t rely on them for food, and their sheer numbers allow them to guarantee plenty of cicadas are born into the next generation — even if birds feast on many of the adults.

Are Brood X cicadas dangerous or harmful to people and pets?

No. Brood X cicadas don’t bite or sting and aren’t poisonous or venomous.

If dogs or cats eat a lot of cicadas, they may get some stomach discomfort due to the hard wings and shells.

Cicadas are not great fliers and sometimes land on humans. They have hard exoskeletons and suckers, though, and could poke your hand if you hold or squeeze one.

Are Brood X cicadas edible?

Yes, but be cautious if you have allergies — especially to shellfish.

If you do decide to chow down on a cicada, you may want to avoid the crunchy, hard shells and wings.

Will Brood X cicadas eat or harm my garden or trees?

Most healthy trees will be able to withstand cicadas, Raupp says. Cicadas eat the sap from trees and lay their eggs on woody branches, especially of young trees.

You can use cicada netting to protect young or recently replanted trees.

If you’re considering transplanting any trees, it’s safest to put it off until the fall planting season.

Should I use pesticides on cicadas?

Raupp advised against using pesticides, since it’s harmful to the cicadas and may not be effective.

How can I have some fun with cicada season?

Play cicada bingo, download the Cicada Safari app to track what you see and tag @nbcwashington in your photos on Instagram, Twitter or Facebook.

News4's Tommy McFly reports on the "Cicada Bingo" adventure planned for Fairfax County.
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