Nashville has seen its share of apocalyptic plagues in the last year, whether the prevalence of COVID-19, or rampant flooding. Luckily though, the whole swarm of insects thing will pass the city by this year.
The second week of May will mark the arrival of the long dormant 17-year periodic cicada in the U.S.
During that time, innumerable large, but mostly harmless, insects, Tennessee’s share of “Brood X,” will spring up from the ground for their long-awaited cyclical mating ritual, which last took place in 2004.
Billions of cicadas are set to emerge in the U.S. this year, with one female capable of laying 400 to 600 eggs during her short, one-month of above ground life before death.
However, according to University of Tennessee Agricultural and Commercial Horticulture Extension Agent David Cook, Brood X will not raise much of a fuss for the Nashville area, specifically.
That, he said, will come three years later.
As Cook explained, in the U.S. the three species of the 17-year periodical cicada, due to emerge in just weeks, are more commonly found in northern states above Tennessee or in eastern Tennessee at higher, cooler elevations.
“If people live on the eastern border of Davidson (County) that adjoins Wilson (County), they’re probably going to see a flurry of activity. It doesn’t mean we won’t get some stragglers that come out in Davidson County, but it was not a significant event by any means 17 years ago,” Cook said.
“I expect people we’ll see a few, but not enough to cancel a birthday party, I’ve had calls about weddings, outdoor events. I had someone from metro school board worried about their central heating and air conditioning units on buildings getting clogged up with cicadas. I think he remembered 2011 when it was a big deal.”
In 2011, Davidson County residents witnessed the reemergence of the three species of the more southern, warmer-climate inclined 13-year periodical cicada, which are due to reprise that appearance in 2024 in plentiful fashion.
“2024 is going to be a gangbusters emergence (for Davidson County),” Cook said.
While cicadas are old news to midwesterners, in 2024 their numbers, size and 80-100 decibel mating call might come as a shock to the system of the abundant transplants from the west coast and northern New England.
But both periodic varieties of cicada are stingless, do not bite and behave similarly, emerging as massive collectives as their internal clocks coordinate with rising seasonal soil temperatures.
“They emerge after dark, late at night. They don’t want to be eaten after 17 years underground. It’s a party for them. They actually get to mate,” Cook said. “You don’t want to make a mistake and come out to early and get eaten by a bird or something. That would ruin everything.”
Cicada eggs are typically laid in smaller “pencil-like” trees before falling to the ground about five weeks of development, when the next generation of larvae will burrow underground and wait for their time in the sun.
The cicadas numbers, Cook said, are a species-level defense mechanism.
“Only so many are going to get eaten. There’s good safety in numbers. Birds get tired of eating them,” he said. “If someone said free hot dogs for two weeks, or donuts, people are going to swarm on that store, then finally go ‘I don’t want to eat another doughnut or hotdog.’”
While cicada habits revolve around laying eggs in and feeding off trees, and then burrowing near tree roots, the cicada offers little risk to its environment, not like that of its far more troublesome migratory grasshopper counterparts, locusts, with which cicadas are sometimes confused.
“People really don’t need to protect any vegetable gardens. Even though the cicadas have a beak type mouth where they can feed, they only go to woody plants like trees and don’t do much feeding at all,” Cook said. “Shrubs generally are not bothered.”
This May, Davidson County residents won’t have to go far to fully experience the rare reemergence, as Hickman, Wilson and DeKalb counties are expected to see huge numbers.
“It’s supposed to be the largest (ever) emergence of the 17-year-cicada (for the region). For the people that have them in their counties this is going to be a big emergence,” Cook said. “People will get tired of counting them.”
Cook advised one way Nashvillians might prepare for 2024, when it will be Davidson County’s turn.
“We’re going to get a lot of calls and we’re going to tell people ahead of time, don’t plant trees in the fall preceding the spring of 2024,” he said. “Those young trees are great targets for them.”
Other targets of the cicada include anything emitting a mechanical hum, which it may mistake for the call of a mate and fly toward.
And the cicadas themselves make a great target for curious pets, though they’re perfectly edible for dogs, cats and even humans.
“There are actually recipes out on the internet, believe or not, on how to make a cicada casserole. I’ve heard they’re similar to asparagus,” Cook said. “I’m not sure I’ve never eaten a cicada. I’ve eaten other insects, but they were well-prepared. I don’t think cicada on a stick would go over very well.”
And if you did get 17-year cicadas in the Nashville area way back in 2004, chances are they’ll emerge in very similar fashion in 2021, as is the case with the 13-year variety from 2011 to 2024. The insects tend to stay very near the place they surface to lay their eggs and repeat the process.
However, Nashville is a very different place in 2021 than it was 2004, and it will likely look even more foreign in comparison come 2024, which can lead to issues due to urban sprawl and development.
“So some areas are going to see diminished populations of cicadas,” Cook said. “The cicadas can’t emerge, they’re trapped underneath, they’re kind of entombed then.
“You’ve seen the growth in Davidson County, my gosh, everywhere someone can buy land they’re putting in homes and businesses. It will be interesting to see what is reported this year in the counties that had previous activity with the 17-year, then it will be interesting to see what’s reported in 2024 with all the urban sprawl continuing.”
While the march of commercialism is likely to continue predictably until then, with nature, Cook said it’s his experience that one should expect the unexpected.
“Sometimes mother nature will surprise us with what she throws at us,” he said.
The UT Extension is asking area residents to keep them informed on any cicada sightings in Davidson to keep data up to date.