- June 9, 2021
Just when people thought it may be safe to take a collective breath after the roller coaster year that was 2020, something big is on the way — and they’re planning on arriving in the billions. Brood X, also known as the Great Eastern Brood, will be emerging from the soil after many years developing
Just when people thought it may be safe to take a collective breath after the roller coaster year that was 2020, something big is on the way — and they’re planning on arriving in the billions.
Brood X, also known as the Great Eastern Brood, will be emerging from the soil after many years developing underground. Brood X is a generation of cicadas (magicicada cassinii) that only appears once every 17 years. Scientists group cicadas based on the year they see the light of day after growing in subterranean bunkers. Some emerge annually, some after 13 years and others after 17 years. Scientists speculate that the unusual, prime-numbered life cycles prevent generations of cicadas from having run-ins with the life cycles of wasps that prey on them. Another theory says the timing reduces the likelihood that 17-year cicadas will mate and hybridize with cicadas of different species or generations.
Brood X is one of the most widespread and prolific cicada generations. The insects are likely to appear mostly along the eastern coast of the United States, but could extend as far west as Missouri and Illinois. Cicadas are preparing to climb trees, start their incessant mating calls, which experts at Iowa State University note have been likened to “pressing scissors against a grind wheel in rapid succession,” and shed their exoskeleton shells in a neighborhood near you. Expect to start seeing them in late April and early May.
Cicadas are unique insects. Despite their large size and bulbous eyes, cicadas aren’t harmful to humans. Nymphs live in the soil and feed on roots. Mature adults come out in the spring to breed and lay eggs after being triggered by warmer soil temperatures. The University of Florida’s Book of Insect Records says the noises cicadas “sing” are how they communicate, reproduce and even scare predators away. The U.S. Department of Health & Human Services states that cicada songs can reach 90 decibels, which is the equivalent of the noise made by a lawn mower or dirt bike.
It is easy to distinguish cicadas from other insects. Cicadas quite large, measuring at .75 to 2.25 inches in length. They have stout bodies, broad heads and clear-membraned wings, according to National Geographic. Cicadas do not eat vegetation, but drink the sap from tree roots, twigs and branches. They also don’t decimate crops like locusts can, though large swarms may overwhelm and damage young trees. Adults will die four to six weeks after emerging, so there’s limited time to get to know this insect before it’s gone for another 17 years. Apart from hearing their calls, people know cicadas have arrived when they find discarded cicada shells on their properties, which are left behind after the insects molt.
Brood X is waiting to peek out of the soil, and communities will have about a month to cohabitate with these interesting insects before they say, “Until we meet again.”