Billions of cicadas should be arriving in May, as they approach their 17th birthdays; the last cicada uprising of this sort took place in 1999. Once they arrive, they’ll be making lots of humming noises and likely serving as a nuisance for residents of states like New York, Maryland, Pennsylvania, Virginia, West Virginia, and Ohio.
According to Discovery News, there are three different species of “17-year cicadas,” while there are others who have a schedule of 13 years. And once temperatures of nighttime soil about eight inches below the surface reach 64 degrees for at least four days consecutive, the 17-year cicadas will crawl to the surface as nymphs, then climb into trees. They then shed their exoskeletons ahead of the mating process.
While cicadas don’t cause any significant damage to plants, and aren’t poisonous nor known for biting or stinging humans, people find them a nuisance due to the noise they create.
“Words seem inadequate to describe that vaguely menacing hum-whistle that seems to be everywhere but emanates from no single place in particular,” wrote David Snyder for the Washington Post in 2004. An Arlington (Va.) resident named Gene Miller also chimed in with his thoughts, saying that cicadas sound like an “alien spaceship coming in.”
The loud buzzing noise made by cicadas is actually a mating call, as males make these sounds to attract the attention of females. Once the mating process is finished, that’s the end of their life cycle, and the start of a new one for their nymphs.
“After the male and female cicada have mated, the female will lay fertilized eggs in slits cut with her ovipositor on small live twigs,” said Russ Horton, an entomologist who spoke to the Post in 2013. “It takes roughly six weeks for the eggs to hatch and the nymphs to emerge.” The nymphs then drop down from the trees and burrow underneath the ground, getting their sustenance for the next 13 or 17 years, depending on their species.