In this video, Matthew Ayres, a professor of biological sciences, explains the lifecycle of cicadas known as Brood X.
“Magicicada is the genus name, and they’re magic,” he says. There are seven species of the insect, four of them with a 17-year lifecycle and three of them with a 13-year lifecycle. They emerge from the ground in large numbers once in a generation. And 2021 is one of those years.
The cicadas are already emerging in some areas of the Eastern Seaboard, the only place on Earth where they exist. The sight of the large winged insects covering the ground, trees, and brush can be alarming, but there’s nothing to fear, Ayres says.
“No place else in the world do we get to witness this,” he says. “So, when you see them coming out in such large numbers, maybe in your backyard, realize that for 17 years they’ve been living beneath your feet. They’re about as benign a natural history splendor as one can find, so enjoy.”