Billions of Brood X Cicadas Expected to Emerge from the Ground

Cicadas usually spend most of their lives one to two feet underground, feeding on the roots and sap of plants. The only time cicadas ever come up to the surface is to mate, breed, and then die. There are over 3,000 discovered species of cicadas, and almost all of them fall into the same two categories: annual cicadas and periodical cicadas.

Annual cicadas are precisely what the name says. These cicadas can be seen above ground once every year, generally in the summer, to mate, lay eggs, and soon die. For two to five years, they live underground and suck on the roots of plants to survive. Around July and August, they climb to the surface and shed their skin to become winged adults. That is when they finally sing, mate, and lay the eggs of the next generation. Annual cicadas tend to lay their eggs inside twigs or tree branches. When the eggs hatch, the newborn cicadas begin to burrow down and stay underground for two to five years. The winged adult cicadas can suck plant juices but only live above ground for about three weeks before they die. Annual cicadas tend to be bigger than periodical cicadas, but in exchange, they have a much shorter lifespan.

Periodical cicadas can be categorized into two smaller groups which are 13-year and 17-year cicadas. Periodical cicadas are well known for their highly synchronized life cycles. Just like their name says, they spend about 13 or 17 years underground as a larva. Similar to annual cicadas, periodical cicadas also feed on fluids from plant roots and share a remarkably similar life cycle. While cicadas are not endangered, these types of cicadas are vulnerable to pesticides and chemicals while buried in the soil. Since they have to spend so long in the soil, they are considered a vulnerable species of insects.

This May, a group of 17-year cicadas known as Brood X, is expected to emerge. Brood X is one of the 15 broods of periodical cicadas. Out of all the 17-year cicadas, they are considered the biggest and most concentrated group. This year, over a billion cicadas, are expected to emerge across 15 different states. John Cooley, a biologist at the University of Connecticut, says, “It’s not something you can ignore… When they come out, it’ll be millions per acre.”

A little while before they finally emerge, the cicadas will begin to dig exit holes in the ground, and when the soil reaches 64℉, the cicadas will fully dig themselves out and start to fly to tall vertical structures. This is where they begin singing their songs to attract mates and lay the eggs of the next generation of Brood X cicadas. Luckily, for people who wouldn’t want billions of cicadas buzzing around our homes, we won’t be seeing the Brood X cicadas for another 17 years.