Swarms of Cicadas to Invade Eastern U.S.

BY Jenny Marder  March 29, 2013 at 12:45 PM EDT

If you live along the mid-Atlantic from North Carolina to Connecticut, get ready to witness the loud and “spectacular” mating ritual of the cicadas. Photo by Michael Raupp.

Sometime around Memorial Day, in the declining hours of daylight, swarms of male cicadas will rise up en masse from the soil, where they’ve lived for 17 years, sucking on plant roots underground. They’ll emerge as nymphs, and begin shedding their exoskeleten in a process called “molting,” revealing wings and an adult body. Then partly flying, partly walking, they’ll start a mad dash up houses and trees to avoid predators. Once safe in the treetops, they’ll spend the remaining months of their lives engaged in a chorus of mating calls, searching for a partner to help continue their gene pool. The females will follow shortly.

“This is the tail end of their lives, but god it’s spectacular,” said Michael Raupp, a professor of entomology at the University of Maryland. “It’s joyous. This last burst of glory is what they’ve been waiting for.”

Not long after mating, females will use an appendage on their abdomen to cut slits into the bark of pencil-sized branches, where they’ll lay their eggs. And a couple months later, tiny cicada nymphs will climb out of these branches, dive bomb from the trees to the earth below, burrow underneath the soil, and start the 17-year-cycle all over again.

While cicadas exist throughout the world, periodical cicadas — the 17-year-variety — are only found in the eastern United States. They are often mistakenly confused with locusts, but they’re more like giant aphids, said John Cooley, a research scientist at the University of Connecticut. Locusts, for example, can do terrible damage to crops. Cicadas are mostly only regarded as a nuisance for their noise.

And it’s no wonder. In populated areas, their chirping can reach 100 decibels — imagine putting your ear up to an active lawnmower, or standing uncomfortably close to a jet engine.

“It’s one of mother nature’s loudest noises,” Raupp said.

Cicadas emerge in swarms, as many as a million per acre, and they grow to 1.5 inches, about the length of a standard triple A battery. They have black bodies, red eyes and clear, cellophane-like wings.

Only males make the noise, and they do so with sound-producing membranes called tymbals, attached to the sides of their bodies like drumheads. Females respond by clicking their wings together.

The periodical cicadas are separated into broods, defined by geography and the date that they emerge. Brood 2, this year’s brood, is expected stretch along the mid-Atlantic from North Carolina to Connecticut. Cooley, who has studied the insects since the nineties, has been preparing maps and a GPS system to track their distribution. He collects his own data, but also relies on citizen scientists to help crowd source the cicada maps. His aim is to understand how the species has evolved as the world’s climate has changed.

As the temperature warms, the nymphs will start building escape tubes to crawl out from the earth. But the internal trigger that prompts them to emerge won’t activate until the temperature reaches 64 degrees Fahrenheit.

Once out, they’ll be subject to heavy predation by birds, mice, skunks, foxes and raccoons. Any large mammal will eat them, Raupp said.

“Their gig is to just be so abundant that they overwhelm the guts and gullets of their predators. Their predators can’t eat enough to do them in.”

If they do appear on your property, Cooley advises against trying to kill them or use insecticide.

“The most important thing to tell people is don’t freak out,” he says. “Don’t try to kill them. Just sit back and enjoy the music, and they’ll be gone in a month.”

QUICK BITES

  • In time for the start of baseball season: engineering the perfect swing.

  • From Reuters: A short cut to the International Space Station.

  • “The skeletal remains of an individual living in northern Italy 40,000-30,000 years ago are believed to be that of a human/Neanderthal hybrid, according to a paper in PLOS ONE,” Discovery News reports.

  • Eye Drops are becoming an increasingly popular poison. One man stands accused of intentionally putting Visine brand drops in his girlfriend’s drink. Another used the same method to poison his father’s milk. The effects, once thought to be relatively mild and even humorous, are no joke, reports Wired Science.

NOT SAFE FOR LUNCH

  • From the New York Times: “This month, New Jersey declared victory in its war against the Asian long-horned beetle, an invasive, hardwood-eating insect that arrived on the shores of New York City in 1996, most likely on wood pallets.”

Photo credit: Swarms of cicada nymphs emerge from the ground. Photo and video by Michael Raupp.

Patti Parson and David Pelcyger contributed to this report.