Friday, December 6, 2013
By Seth Borenstein / The Associated Press
(Continued from page 1)
Gary Hevel, a research collaborator with the Department of Entomology at the National Museum of Natural History, holds up a preserved cicadas.
The Associated Press
Any day now, cicadas with bulging red eyes will creep out of the ground after 17 years and overrun the East Coast with the awesome power of numbers. Big numbers. Billions. Maybe even a trillion. For a few buggy weeks, residents from North Carolina to Connecticut will be outnumbered by 600 to 1.
2003 Associated Press File Photo/University of Connecticut/Chris Simon
"These guys have evolved several mathematically clever tricks," Raupp says. "These guys are geniuses with little tiny brains."
Past cicada invasions have seen as many as 1.5 million bugs per acre. Of course, most places along the East Coast won't be so swamped, and some places, especially in cities, may see zero, says Chris Simon of the University of Connecticut. For example, Staten Island gets this brood of cicadas, but the rest of New York City and Long Island don't, she says. The cicadas also live beneath the metro areas of Philadelphia, Baltimore and Washington.
Scientists and ordinary people with a bug fetish travel to see them. Thomas Jefferson once wrote about an invasion of this very brood at Monticello, his home in Virginia.
While they stay underground, the bugs aren't asleep. As some of the world's longest-lived insects, they go through different growth stages and molt four times before ever getting to the surface. They feed on a tree fluid called xylem. Then they go aboveground, where they molt, leaving behind a crusty brown shell, and grow a half-inch bigger.
The timing of when they first come out depends purely on ground temperature. That means early May for southern areas and late May or even June for northern areas.
The males come out first – think of it as getting to the singles bar early, Raupp says. They come out first as nymphs, which are essentially wingless and silent juveniles, climb on to tree branches and molt one last time, becoming adult winged cicadas. They perch on tree branches and sing, individually or in a chorus. Then when a female comes close, the males change their song, they do a dance and mate, he explained.
The males keep mating ("That's what puts the 'cad' in 'cicada,'" Raupp jokes) and eventually the female lays 600 or so eggs on the tip of a branch. The offspring then dive-bomb out of the trees, bounce off the ground and eventually burrow into the earth, he says.
"It's a treacherous, precarious life," Raupp says. "But somehow they make it work."