Residents in the Northeast U.S. waiting for warm temperatures may get a surprise along with their May flowers: When the soil reaches 64 degrees Fahrenheit, they’ll also get a visit from billions and billions of cicadas.
This latest brood is composed of several species including Magicicada septendecim, M. cassini and M. septendecula, and is expected to take over West Virginia, Virginia, Maryland, New York, Ohio, Pennsylvania and a tiny spot on Long Island.
In an event that only happens once every 17 years for this brood, the creatures will soon dig their way out of the soil, shed their exoskeletons and emerge en masse. The swarm will spend two to six weeks mating and singing their grating, sing-song call before dying and blanketing the ground with their crispy brown corpses.
Entomologists have identified 14 broods of periodic cicadas in the U.S. which only emerge at 13 and 17-year intervals. Cicadas spend the vast majority of their lifecycle as grubs, burrowing through the ground feeding on the juices of plant roots, according to The Christian Science Monitor. After emerging from the ground and mating, the female cicada lays her rice-grain sized eggs on a tree branch. Then the adults die while the nymphs crawl their way to the edge of the branch, dropping to the ground below where they burrow into the soil and wait for another 17 years.
Researchers have theorized that the insects spend such a lengthy time underground in an effort to outlive parasites that may harm them, Eoin O'Carroll wrote for The Christian Science Monitor in 2013. Other researchers speculate that the 13 and 17-year life cycles, both prime numbers, are an evolutionary adaptation and a mathematical trick that keeps cicadas from emerging during peak population periods for their predators.
“A cicada that emerges every 17 years and has a predator with a five-year life cycle will only face a peak predator population once every 85 years,” writes Patrick di Justo in The New Yorker, “giving them an enormous advantage over less well-adapted cicadas.”
Getting caught in a swarm of the red-eyed cicadas is both awe-inspiring and frightening. The 1.5-inch insects can reach a density of 1.5 million insects per acre. But people have nothing to fear. The cicadas drink only tree sap and don’t bite, sting or cause serious crop damage.
The hordes of insects may drive some people away, but for some areas it’s become a tourist attraction—some resorts even advertise the insects, Ohio State University professor Dave Shetlar tells CNN. “They have visitors that are coming from China and Japan and European countries [who] want to come and experience the cicada emergence,” says Shetlar.
One particular hotspot embracing the swarms is Cleveland, which will host cicada walks, talks and a festival. “It’s going to be a wild ride," Wendy Weirich, director of Outdoor Experiences for the Cleveland Metroparks tells Cleveland.com. “It’s like Rip Van Winkle for insects.”