Carl & Ann Purcell

Meet Brood X: Billions of Cicadas Emerging Soon Within Eastern U.S.

Do you hear it? If you live in the Eastern U.S., it's likely the noisy entrance of the cicadas from Brood X as they emerge for the first time in 17 years.

April 22, 2021

The biggest red carpet since 2004 is rolling its way down the Eastern United States, where some will be lucky to catch an eye at the billions of cicadas that will soon be appearing from beneath the soil. The cicada insect is part of a group which stems from the “Great Eastern Brood,” commonly referred to as “Brood X” meaning they’re expected in geographic regions from Tennessee to New York, according to CNN. And don’t worry, east coasters, cicadas are not harmful to humans or animals (phew!).

Philippe Lebeaux / 500px

Cicadas, specifically part of Brood X have been living a “subterranean” life for 17 years. Kritsky, author of the new book "Periodical Cicadas: The Brood X Edition explained, “Brood X — the "X" is the Roman numeral for 10 — is the largest group of 17-year-cicadas. (Other periodical cicada groups emerge on a 13-year-cycle.)” As soon as they reach the Earth’s surface, it’s game on for finding a mate. The male cicadas create a loud buzzing noise (otherwise known to humans as a song) by flexing their drum-like organ called a tymbal. When enough are around and in sight, most refer to the cicada calls as similar to a chorus!

Entomologist Eric Day, of Virginia Polytechnic Institute and State University extension has made it clear that this “unusual biological phenomenon” is something many won’t want to miss. Surprisingly, periodical cicadas are only found in the Eastern United States and they typically die four to six weeks post-appearance.

When does the show start, you might ask? As soon as the soil reaches 64 degrees Fahrenheit and, depending on the geographic region, the first or second week of May. Scientists and entomologists alike are unsure of the specific purposes of the cicada schedules or why they have “prime-numbered life spans.” Luckily, the emergence of Brood X is quite large and aids the insects in surviving predation and successful mating. Brood X stands out among other broods in the fact that their appearances are commonly found to be within vicinities of large metropolitan areas. "About 35 million Americans will have the opportunity to interact with Brood X," Kritsky said. Early signs of their emergence can be seen by finger-size holes in the ground near the base of trees or a “chimney-like tunnel” appearing from the soil.

Eriko Koga


For those who would like to catch a glimpse at this phenomenon, cicadas can be found in Delaware, the District of Columbia, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, and Virginia.

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