COLUMBIA, S.C. — The din begins this spring.
Get ready for the swarm of critters that emerge from underground every 13 years and fill the air over much of the Southeast United States with their ear-splitting mating calls.
Scientist call them periodical cicadas, Brood 19. Writers often mislabel the red-eyed, 1½-inch-long insects as locusts, as in biblical plagues. cicada emergence
Doomsdayers might add the upcoming infestation to recent End of Days events: thousands of birds falling from the skies in two states or the tens of thousands of fish washing up on the banks of the Arkansas River.
But the event is more of natures clockwork than the end of time on Earth.
As ground temperatures approach 64 degrees, the four species of 13-year cicadas will dig out at night from burrows where they have sucked sap from roots for more than a decade.
Cool! or yuck!, depending on your sensibilities.
Entomologists dont know exactly what triggers their emergence, but the date does not vary much among generations.
Periodic cicadas are amazing in their ability to be synchronized, said Clemson University entomologist Eric Benson. Almost overnight, tens of thousands emerge in an area. Its something to behold.
He predicts the swarms will rise about late April or early May, based on weather conditions in the spring and their behavior in 1998, the year of the most recent emergence. Other species of smaller cicadas come around every year.
Concentrations of the 13-year variety have been known to reach 1.5 million per acre in some places. But more commonly, the density is in the hundreds of thousands per acre, scientists say.
No one in South Carolina is counting to see how thick the swarms will be. In the past, Clemson relied on anecdotal observations from its Extension Service agents. But the professor who led that effort has retired.
You only have a month to study something that happens every 13 years, said J.C. Chong of the Pee Dee Research and Education Center in Florence. Maybe thats why nobody is studying it.