What states can expect to see Brood X?
Brood X is expected to emerge in about 18 states, Dr. Kasson said.
In the past, Brood X cicadas have been spotted as far north as Michigan, as far south as Georgia, and as far west as Illinois. Other states where they might emerge include Kentucky, Ohio, New Jersey, New York, Pennsylvania and Tennessee.
Brood X, which is also known as the Great Eastern Brood, has three epicenters across portions of the country. One will be in the Washington, D.C., area, including Northern Virginia and parts of Maryland. Another will be rooted in Indiana, and there will be a smaller one in and around Knoxville, Tenn., Dr. Kasson said.
Not all states will see large emergences of cicadas, said Chris Simon, a professor of ecology and evolutionary biology at the University of Connecticut. “Some of them, it’s just a tiny little corner,” she said.
Other states, like Texas, get cicadas every summer, but those are typically annual cicadas or another type, Dr. Simon said.
Are cicadas dangerous?
Because they feed off plants, cicadas can injure small trees and shrubs but cause no harm to humans, Dr. Kasson said.
“They’re just really big and awkward,” he said.
If anything, he said, Americans should consider themselves lucky to witness the phenomenon. “It’s really something to marvel at,” he said.
They can, however, be annoying because of the sharp buzz they make when they’re looking for mates.
“Males go on a singing spree,” Dr. Kasson said, adding that in some areas with many cicadas, the sound can be deafening. “It results in this cacophonous shrill.”