Return of the Cicadas: Double Trouble!
Nashville Cicadas 2024
For the Eastern United States, springtime in 2024 is going to be unique! Two broods (or breeding groups) of periodical cicadas will emerge. Although Nashville will only see one of these two groups, the insects will be in much larger numbers than the annual cicadas that we hear in summer every year. If you’re located in Wilson or eastern Davidson counties, you may want to avoid making outdoor plans between May and July of this year, when the cicadas will be out in full force for several weeks.
What to Expect From Cicadas in Tennessee This Year
We checked in with one of the Nashville Tree Conservation Corps’ resident ISA board-certified master arborists, Bo Arington, to learn a bit about what we should expect. He told us, “They should start popping up around mid-May. Most of them should come up around the same time, but some will be later than others.”
The cicadas usually survive for a few weeks once they’re above ground, and their timing all depends on the weather and location, which can be variable even within Davidson County. Since their mating season only lasts for about a month, the periodical cicadas should be gone by July.
What’s the Difference Between Periodical and Annual Cicadas?
The periodical cicadas that will emerge this year are different from the ones we hear every summer (known as annual, or “dog day,” cicadas). The periodical species, which emerge in the spring of their cycle year, are smaller in size, with black and orange bodies and red eyes, compared to the larger green and brown, black-eyed annual ones.
Annual cicadas are smaller in number, which is why periodical emergences are so notable; there’s a good reason that this brood emergence is being called a “cicadapocalypse.” Thousands, even millions, of periodical cicadas can emerge across a single acre; it’s expected that billions in total will emerge across the US this season. This is why they will be particularly loud this year—that many cicadas singing at once can even drown out the sounds of a jet engine!
Broods XIII and XIX
The last time that these two broods (XIII and XIX) emerged at once was in 1803, 221 years ago! In that year, Thomas Jefferson was president, the Louisiana Purchase was completed, and Nashville wouldn’t be incorporated as a city for another three years, in 1806.
Brood XIX, a group that emerges every 13 years, is the cicada population that we will see across the Nashville area this year. This is the most widespread group, which is one of the reasons they’re making national news. Brood XIX cicadas will emerge in Tennessee, the Carolinas, Alabama, and Arkansas, with some of the most widespread emergence occurring in Missouri and the southern half of Illinois.
Brood XIII, a 17-year emerger, is located in the upper Midwest: in the northern half of Illinois, eastern Iowa, and southern Wisconsin. It’s only in central Illinois and southeastern Iowa where the two broods will be emerging in the same place, with only very small areas of overlap.
It’s believed by experts that broods remain in distinct areas, with very little overlap, as an evolutionary result that helps species keep their biologically driven breeding cycles intact. The 13-year and 17-year cicadas have multiple species within those brood groups, and it's thought that these odd-numbered, spaced-out emergence cycles are a way for breeding populations to be successful by not aligning with predator reproductive cycles.
Managing the Periodical Cicada Emergence
Cicadas live underground for most of their lives, coming up above ground to reproduce and lay their eggs in the branches of trees, after which time they die. While the cicadas are active, though, they are a nuisance at most. Unlike locusts or tree-boring beetles, they don’t bite, and they don’t decimate trees, gardens, or crops. Mostly, they just get in the way and make a lot of noise!
The number of periodical cicadas might, however, damage young or small trees that haven’t yet developed thick bark and sturdy branches. Arrington advised us on how to safeguard saplings and understory trees: “One thing people can do to protect small or young trees is to cover them in fine nets or wrap the branches in burlap. Smaller ornamental trees are more likely to be killed by cicada damage than larger, more established trees.”
Pet owners should keep an eye on their animals during this period. While it will be a veritable feast for large birds like geese and ducks, as well as many mammals and even some humans who can sauté or grill the bugs as a protein source, cats and dogs might have some sensitivity to the shelled insects. If your pet seems sick after ingesting a cicada, have them checked by a veterinarian to be sure they’re cared for properly.
If you’re hoping to be able to plant one or more trees this year, don’t worry! The cicadas will have passed by the fall, which begins the tree-planting season here in Nashville. Check out NTCC’s tree sale to find the right trees for your landscaping needs, and consider volunteering with us to help get more trees in the ground across the city. For regular information on Nashville’s canopy, subscribe to our email newsletter!