The US is preparing to experience trillions of cicadas surfacing across as many as 16 states in the country this year. These pudgy insects with bulging orange eyes are known for their extraordinary, highly synchronized life cycles. Unlike annual cicadas, periodical cicadas – of which there are just 10 species – spend most of their lives in larval form, buried beneath the soil and feeding on plant root fluid.
But this year their emergence will be a dramatic spectacle as two groups of cicadas are expected to erupt from the earth simultaneously for the first time in several hundred years. The broods are known as Brood XIX and Brood XII. Their joint appearance is rare as this concurrent event has not happened since 1803 and won’t occur again for another 221 years.
Brood XIX is the largest of all periodical cicada groups and they emerge after being dormant for 13 years underground, while Brood XII is a smaller group that appears every 17 years. Trillions of cicadas are expected to burst out of the earth in as many as 16 states.
The cicadas will emerge in central North Carolina, eastern Tennessee, north Arkansas, southern Missouri, Southern Illinois and western Kentucky. The cicadas will then appear throughout central and northern Missouri and Illinois, northwestern Indiana, southern Wisconsin and eastern Iowa.
While the bugs are harmless, the collective sound of the males’ persistent mating songs will create an extraordinary – and hard to ignore – noise.
According to John Cooley, an entomologist at the University of Connecticut, the cacophony of cicada mating calls will create a loud, haunting mix of sizzling noise, buzz-click sounds and droning that "can be pushing 120 decibels if you're right inside that chorus."
"That's sort of like getting too close to a jet engine," he adds.
The cicada's swarm is predicted to begin in late April and will last as long as six weeks. In most cases the cicadas will only live about a month before dying near where they first emerged, said Floyd W. Shockley, an entomologist and collections manager at the Smithsonian Museum of Natural History. Shockley adds the cicadas' dead bodies will build up to such a point that they will have to be removed.
“In urban areas, there will be sufficient numbers to necessitate removal of their bodies,” Shockley said. “But rather than throwing in the trash or cleaning up with street sweepers, people should consider them basically free fertilizer for the plants in their gardens and natural areas.”
Live cicadas are also beneficial to the environment according to one report. They act as natural tree gardeners and the holes they leave behind when they emerge help aerate the soil and allow for rainwater to get underground.
“The forest is where they live,” explained Cooley. “They are a part of the forest. Don’t try to kill them. Don’t try to spray insecticide, all that kind of thing. That’s just going to end badly because there are more than you could possibly kill with insecticide. You’d end up killing everything.”
There is one other aspect of “cicada-geddon” worth noting: some of the bugs will be infected by a sexually transmitted fungus that makes them hypersexual. The fungal pathogen is called Massospora cicadina and it causes the backside of adult cicadas’ abdomens to open up. A chalky white plug erupts and takes over their bodies, making their genitals fall off.
"The cicada continues to participate in normal activities, like it would if it was healthy," said Matthew Kasson, an associate professor of Mycology and Forest Pathology at West Virginia University. "Like it tries to mate, it flies around, it walks on plants. Yet, a third of its body has been replaced by fungus. That's really kind of bizarre."
Kasson says the fungus acts as a type of amphetamine and gives the bugs their stamina.
"But there's also something else unusual about it," he said. "There's this hypersexualized behavior. So, males for example, they'll continue to try and mate with females – unsuccessfully, because again, their back end is a fungus. But they'll also pretend to be females to get males to come to them. And that doubles the number of cicadas that an infected individual comes in contact with."
While researchers believe the fungus is transmitted sexually, they aren’t sure of where the fungus originates. But they suspect that when the cicadas die the spores get into the soil and infect unhatched cicadas underground. For now just less than 5% of the cicadas are infected with the fungus.