What to Know About the Cicadas in Nashville

Will a Cicada Apocalypse Hit Nashville This Spring?

The buzzing of Tennessee Cicadas is a familiar sound of spring and early summer in Middle Tennessee. Cicadas usually provide a background hum for the season, but in some years, cicadas emerge in large numbers and swarm the area—occasionally damaging young trees. 

You may have heard that in May, the emergence of a large group of Tennessee Cicadas known as Brood X will affect parts of 15 states, including Tennessee. Does this mean Nashvillians will soon need to take cover from the dive-bombing bugs? 

David Cook, the University of Tennessee extension agent for Davidson County, says the last big local emergence occurred in 2011, when millions of Tennessee Cicadas came out of the ground on May 11. But David reassures us that cicadas won’t be as numerous in Nashville this year, though there will be some Tennessee Cicada activity in Wilson County and eastern Davidson County. The next big emergence in Nashville, he warns, will be in spring of 2024. 

The Cicada Life Cycle

Tennessee Cicadas are known for their 13- or 17-year periodical emergence, which usually begins in the first week or two of May. The soil warms up to a specific temperature and signals to the cicadas to move to the surface and emerge. Cicadas live in wooded areas and locations that have been recently developed but maintain exposed soil and trees, like rural areas, subdivisions or parks.

Female Tennessee Cicadas are attracted to stems that are about the width of a pencil and will slice into the underside of a branch to insert a dozen eggs. They’ll do this to several trees, and after a while, the eggs will hatch, and the larvae will fall (or as David described it, “float,” due to their tiny size) to the ground and instinctively burrow into the soil. During the 13 or 17 years spent underground, the insects don’t cause any significant injury to the root system of nearby trees. 

David explains, “Life is pretty fragile as an insect; you’re at the bottom of the food chain. Most insects don’t have long lifespans because they’ll be eaten, so they don’t have regular generational turnover like Tennessee Cicadas. Since cicadas live underground and emerge only once, they can be tracked, and we can know when to expect them. Comparatively, they don’t do much damage to plants or humans; there are other insects to be more worried about.” Nevertheless, there is a bit of danger with Tennessee Cicadas around young trees. 

Potential Long-Term Branch Damage

When females emerge from the ground, they feed on plants like any other insect but don’t cause extensive damage in doing so. The potential for damage comes when Tennessee Cicadas lay their eggs in very young trees and shoots. The damage done by an incision is a physical injury that can make a branch structurally weak in the long term and might cause it to break as the branch grows and gains more weight. This is something that can be caught with regular tree care by a certified arborist. If limbs are inspected every year or two, a structural weakness like that can be removed before it becomes a danger to people or property.

According to David, cicadas don’t necessarily target any specific tree other than those in abundance. For example, cicadas are often found in dogwoods, which are found in cities like Nashville since they’re such a popular tree to plant. Cicadas prefer small- to medium-sized trees, and big older trees with many layers of bark will be ignored. New growth is sought after, so trees like maples might also be targets since new shoots on branches are prime material for the cicadas to lay their eggs. 

What Can Homeowners Do to Manage a Large Cicada Emergence?

David says that there isn’t much that can be done to prevent Tennessee Cicadas from laying their eggs, but there are some things that homeowners can do to be proactive and avoid damage to young trees. For many reasons, it’s generally advised to plant trees in the fall or winter. That’s especially helpful for avoiding cicada damage, because these insects usually die off by the end of July. For the next big emergence in 2024, David advises not to plant a tree that year until after the cicadas have passed. 

It’s important to keep in mind that Tennessee Cicadas aren’t all bad news for trees and humans — they offer many benefits to the local ecosystem and tree canopy. During their lives underground, they help the soil remain bioactive, eating and decomposing other organic life, making nutrients available for plants and trees to grow. Once they emerge, they are food for birds and other animals, and when they die, the decaying organic matter releases nutrients back into the soil, fertilizing for a flush of new growth of plants. Plants, trees and soil absorb excess rainwater and regulate temperatures, some of the many ecosystem services we rely on every day. 

If you’re located in Wilson or eastern Davidson counties, you may want to avoid making outdoor plans in May-July 2024, when the cicadas will be out in full force for several weeks. They won’t bite, but they may land on you or in your food. David reminds us, “Dogs and children can be curious, and they tend to put things in their mouths, including bugs. Eating a cicada won’t hurt, though; they’re a protein source, and people say they taste like asparagus.” 

If you’d like to learn more about caring for young trees and managing your yard for insects, reach out to us here at the Nashville Tree Conservation Corps!