A Group of 17-Year Cicadas Will Emerge in 14 States This Summer

In a few months, you'll likely be able to enjoy sunsets outside with a little something extra: A loud chorus of cicadas. Along with the bugs that appear annually, there are also periodical cicadas that only come out every few years. Basically, It's like the insect world's version of Rip van Winkle, the folk story character who fell asleep for 20 years. Some periodical cicadas only emerge every 17 years, and a group of them (which scientists call Brood X) is expected to emerge this year across much of the Eastern United States for the first time since 2004, according to the Baltimore Sun. But other than making a racket for a few weeks and maybe giving you the heeby-jeebies because of their large size and sheer numbers (millions of them are expected to appear), these fascinating insects are harmless to people.

Where and When Will 17-Year Cicadas Appear?

Brood X is expected to make an appearance in May, once the ground temperature has reached 64°F, in Delaware, Georgia, Illinois, Indiana, Kentucky, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. Other broods of periodical cicadas live as far west as Nebraska and south as Texas, but Brood X is the only group of 17-year cicadas expected to emerge this year.

All cicada larvae live underground, but some species spend much longer there than others. Annual cicadas usually stay underground for two years, but the adults emerge every year for mating (which is why you hear cicadas singing every summer). Periodical cicadas, on the other hand, only emerge every 13 or 17 years, depending on species. When they finally appear as adults, they'll spend 4-6 weeks above ground to mate and lay eggs for the next generation. Periodical cicadas have black bodies just over an inch long with yellowish wings and red eyes, while annual cicadas tend to be brown or green with dark eyes and black or green wings. The rasping drone they create en masse can reach the volume of a lawn mower.

Do Cicadas Damage Plants?

For the most part, you don't have to worry about cicadas doing any damage in your garden. However, periodical cicadas appear in much greater numbers when they do emerge, so there's a chance that they can end up damaging trees when laying eggs. Female cicadas create tiny slits in smaller twigs and branches to deposit their eggs. A few of these cuts won't hurt a tree, but if hundreds of the bugs lay their eggs on the tree at once, you may notice some dead branches later in the season. Usually, you can trim these twigs off and your tree will be just fine. Using pesticides to control them is not recommended because the chemicals won't slow them down for long, but would likely kill other beneficial insects in the area.

If you live where periodical cicadas are emerging this year, you may want to delay planting any new trees. It can be harder for young saplings to recover from damage, so it's best to wait until the cicadas are finished laying eggs, usually about two months after their first appearance. The eggs hatch after about six weeks, then the larvae drop to the ground and burrow into the soil. And for Brood X, that's it until they make their next above-ground appearance in 2038.