CHARLESTON (KDKA/CBS LOCAL) – This spring, residents in 15 eastern and central U.S. states won’t be able to miss the mass emergence of billions of cicadas. They come out of the ground when it reaches a certain temperature. And now, there’s an app for tracking them.

Loud and large, Brood X is one of the largest and most widespread of the periodical cicadas. After being underground for 17 years, billions are popping up.

READ MORE: Former Mylan Executive Pleads Guilty To Insider Trading, Preparing False Tax Return

While they may not be here in western Pennsylvania, our neighbors in West Virginia will be in for that unique buzzing sound.

RELATED STORIES:

Gene Kritsky is dean of Behavioral and Natural Sciences at Mt. St. Joseph University.

“If you look out your window in the early evening, you’re gonna see, literally, hundreds of cicada nymphs coming out of holes in the ground,” he says.

They’ll stay above ground for five to six weeks before blanketing lawns with their littered shells.

READ MORE: Pittsburgh Steelers WR JuJu Smith-Schuster Visits Western Pennsylvania School For The Deaf, Learns Sign Language

And of course…there’s the noise.

Kritsky says he’s measured their mating calls at nearly 100 decibels. “It just doesn’t stop!” he says, “It’s like what happens to you if you go to a rock concert, and you walk out and you still hear the vibration.”

Brood X will appear in 15 states, impacting some 35 million people, perfect for crowd-sourcing information, with Kritsky’s free app Cicada Safari. “If they see a cicada, they take a picture of it,” he explains. “Once that picture is approved, it goes on a live map that people can follow the emergence when it starts in northern Georgia and slowly moves north.”

While cicadas can be a nuisance, they don’t sting or bite and aren’t poisonous. Kritsky, however, recommends waiting to plant new trees after the cicadas are gone.

And until they’re gone, wedding planners have learned to adjust: Jessica Doan is a wedding planner. She recommends, “Maybe investing in a tent and then talking to your DJ. You want to make sure you can kind of drown out the noise.”

In fact, Kritsky says cicadas and weddings have something in common: “Periodical cicadas are the bugs of history. They’re like markers in life events. You’ll remember it the first time you experience one.”

MORE NEWS: CDC: Salmonella Outbreak Sickens Over 100 People, Including 2 Pennsylvanians

Even if you’re a city dweller, you won’t escape the cicadas. Brood X is also expected to emerge this time in urban areas where conditions are favorable.