Where billions of cicadas are about to emerge, in one map

For the last 17 years, a group of cicadas known as Brood XIV has been buried several inches underground, doing very little. This particular batch of insects has missed a global pandemic, Donald Trump winning two presidential elections, Brexit, multiple wars, and more.

Now they’re about to emerge.

Across large portions of the eastern US, from Long Island to central Tennessee.

Around May and June, the noisy insects will erupt from the ground and live only for a few weeks — just long enough to find mates and lay eggs — before dying. Once their offspring hatch, the young will bury themselves underground, remaining largely oblivious to the world for another 17 years.

The map above, which shows Brood XIV in neon green, provides only a rough approximation of where different broods will appear. For a more granular map, check out this one the University of Connecticut provided. This year’s brood is similarly shown in neon green on that map.

Eastern North America is the only place in the world where you find periodical cicadas — groups of cicadas that emerge from the ground every 13 or 17 years, depending on the brood, or group. Slightly different kinds of cicadas, known as annual cicadas, appear every summer and have a global distribution. (How do cicadas count years? Likely using the flow of tree sap, as I explain here.)

Brood XIV is the second largest brood of cyclical cicadas and surfaces every 17 years.

While brief, the coming insect explosion will shape ecosystems for years to come. These pulses of bugs provide food for pretty much everything in the forest and have been shown to increase bird populations and shift the hunting patterns of other species. As one study put it, pulses of periodical cicadas can “rewire” entire forest food webs.

If you come across what you think is a Brood XIV periodical cicada, report it! You can download an app called Cicada Safari to submit your photos. It’ll help the researchers who study them.