NASHVILLE, Tenn. (WTVF) — It may be hard to find someone more excited about the upcoming rare double cicada emergence than Rob Kraker.
“This is a part of nature, and it's actually pretty cool that we get to be a part of that. The last time this happened was when Thomas Jefferson was around — 221 years ago!”
Once the ground warms to the mid-60s, likely in May, we can expect two cicada broods to emerge: the 17-year Brood XIII and the 13-year Brood XIX.
I spoke with Kraker — a certified tree arborist with The Davey Tree Expert Company — about the species, and he told me that the insect is helpful.
“They actually help aerate the soil — they emerge from up to 8 feet to 8 inches. So when they make those tunnels, it's about a quarter of an inch to a half an inch. By doing that it actually helps aerate these Tennessee clay soils — which then in turn water gets down these passageways and other organic matter goes into those tunnels," Kraker said. "If you really want to get into it, the exoskeletons that are on the trunks — those break down into the soil and provide nutrients into the roots. Normally they fall off and fall around the root crown of a tree, which is basically your highway of nutrients for that tree.”
Cicadas lay their eggs on tree limbs which can cause some die-back. Kraker says it won’t bother mature trees, but the new landscape is worth keeping an eye on.
“On your hardwoods or on your bigger trees, you will have cicadas and you will see the exoskeletons on the side of the trunks but that is not a bad thing. If it's a younger tree or a newly planted tree you're definitely not going to want a heavy infestation on one of those trees. You're never really supposed to prune more than a quarter of the live growth,” he said.
Kraker says you may need to place a net around the new landscape to deter the insects.
Cicadas are known for their high-pitched buzz which can reach 100 decibels, their beady eyes, and three-inch wingspan, but Kraker says just remember — they don’t bite!
“The nice thing is they do not have chewing mouth parts, so you don't have to worry about them biting you.”
