Breakdown: Why this year’s cicadas will be more numerous & loud

Published: May. 7, 2021 at 1:18 PM CDT
Email This Link
Share on Pinterest
Share on LinkedIn

MEMPHIS, Tenn. (WMC) - You may soon hear a loud, familiar sound in just a few weeks! After living quietly underground for 17 years, a group of periodical cicadas called Brood X will emerge from the earth to fill outdoor spaces and share their inescapable mating calls.

This is the same buzzing and massive brood that became the soundtrack of the Summer 2004 with their harsh mating call loud enough to drown out the sound of thunder.

This is a big one, a generational event. We’re talking billions of cicadas across 15 states – including portions of Tennessee.

These 17-year cicadas are found nowhere else on the planet except on the East Coast and in the Midwest.

Where billions of cicadas will emerge this spring (and over the next decade), in one map
Where billions of cicadas will emerge this spring (and over the next decade), in one map(United States Forest Service)

An exact date is hard to pinpoint, but their return typically starts around early-to-mid May. A warm rain will trigger their debut, Entomologists (scientist who studies insects) say, and they’ll slowly begin to overtake the area. They emerge when soil temperature hits 64 degrees Fahrenheit, usually around dusk.

They don’t all emerge at once. It takes about two weeks for all of them to dig out from underground, so there may be a few stragglers that linger far into the summer.

Once they do surface, they make a mad dash for a nearby vertical structure, often the tree whose roots sustained them.

At their peak, you can expect to see cicadas on trees and on the façade of your home -- seemingly everywhere.

They’re relatively harmless to living things and are mainly just a a nuisance, flying into windshields and littering your yard with tiny carcasses.

They don’t sting or bite. They won’t wipe out fields or gardens, and though they may land on them, they won’t feed on them.

Once they attach themselves to a structure, they’ll begin to shed their exoskeletons. After a few days resting and waiting for their shells to harden, the mating begins and the males start emitting their high-pitched mating song. They attract mates by rapidly vibrating drumlike tymbals on the sides of their abdomen to produce their distinct sound.

These insects can emit sounds between 80 and 100 decibels, which is on par with the level of a low flying airplane or a lawn mower.

Their life span is roughly four to six weeks above ground and they’ll die in late June into July. After the cicadas mate, each female will lay hundreds of eggs in thin tree branches. When the eggs hatch, new cicada nymphs will fall from the trees and burrow back underground, starting the 17-year cycle again.

It’s a natural cycle that cicadas have followed for thousands of years.

Copyright 2021 WMC. All rights reserved.