Summer of the Cicada
For 17 years they've been out of sight, out of mind. Now they will be in your face. Get set for Brood X
Telltale holes, each about the size of a dime, recently started appearing in the soft spring earth beneath big trees on the University of Maryland campus in College Park. Entomologist Mike Raupp can hardly contain his excitement. In a few weeks, the massive cicada community known as Brood X will suddenly emerge from the ground after lurking underfoot for 17 years. Billions of the large, red-eyed bugs will fly clumsily around 15 eastern states in a brief mating frenzy, shrieking in a daytime din that can rival a jet engine. "This is just going to be a wicked cool biological event," says Raupp. He's already gotten out his frying pan and dug up some immature ones to show students that the critters make good eatin', too.
Ann Weinberg, a telecommunications consultant in Arlington, Va., isn't so thrilled. The first Brood X invasion she experienced, in 1987, left her shell-shocked. "Number one, they're so big. Number two, there are so many of them, millions of them, that it's like a Hitchcock movie, The Birds. Number three, they tend to fly right into you." Weinberg is glad she telecommutes so she can hide indoors until they disappear.
Fast life. That won't take long. While Brood X spends nearly two decades underground, sucking sap from tree roots, a cicada's life in the world above lasts just weeks. When the dirt warms up in late spring, the soft-bodied nymphs, or immature cicadas, climb the nearest vertical object, which they hope is a tree. There they cling until they are ready to split their amber- colored shells and emerge as winged adults. The males sing to attract mates, which lay ricelike eggs inside a tree branch. The adults die, and soon the hatched young fall to the ground, burrowing in to await 2021 and their own summer of love.
Nearly every year in early summer, one of many tribes of 17- and 13-year cicadas pops up somewhere on the East Coast, weeks before the "dog-day" cicadas, which have shorter sojourns underground and emerge in smaller numbers. But among "periodical" cicadas, Brood X has gained special notoriety. It's the 17-year brood with the greatest numbers and the largest geographic range, hitting many major cities. Accounts of Brood X date all the way back to 1715, says cicada expert Gene Kritsky of the College of Mount St. Joseph in Cincinnati.
By coming out all at once, in a staggering swarm, Brood X overwhelms birds and other predators, so each individual bug has a good chance of surviving to mate. And since they pop up so infrequently, few predators have evolved to depend on the insects as a routine food source. But no one is sure how periodical cicadas keep track of time. They may have a way to count seasonal changes in their tree-sap diet; a few years ago, scientists found that cicadas came up early if the tree they fed on was artificially forced through more than one flowering cycle in a year.
Plenty more puzzles remain for scientists to study when this year's emergence begins. Kritsky, whose new book, Periodical Cicadas: The Plague and the Puzzle, is out next month, wants to figure out how different broods are related and whether they interact underground. Others are gearing up to study mating habits and long-term effects on trees.
Every one else will just have to live with them for a few weeks. "They don't bite or sting. If they land on you, just flick them off," says Smithsonian Institution entomologist Gary Hevel. But brides planning outdoor weddings are worried; Kritsky has counseled over three dozen already. And throughout Brood X's domain, people will have to endure an ungodly racket, which thankfully stops at dusk. Cicadas have a drum-like organ they vibrate with their abdominal muscles, creating a sound that's amplified by their hollow bodies.
Sad songs. Not everyone hates the cacophony. "The cicada, to me, produces a very interesting sound," says acoustical engineer Tamara Smyth, who created a computer synthesizer that lets people "play" the insect's instrument. During the 1970 emergence, the singing cicadas inspired Bob Dylan's "Day of the Locusts" (locust is a common misnomer for cicada). This time around the bugs will get star treatment on a new CD, Seventeen Year Itch. Featuring cicada-themed songs and cicada sounds, it was commissioned by a Cincinnati civic group to highlight the return of the city's 5 billion insect denizens. Most of the songs focus on the pathos of the cicada's love life. "They've only got a month to, you know, do their business, and then they die," observes guitarist Jacob Heintz of the rock group Buckra.
The imminent insect love frenzy has created more anticipatory panic than usual this year, says Kritsky, who thinks the explanation may lie in terrorism and other current menaces. With all the world's unknowns, he notes, it's weirdly comforting to know there's a coming plague that's totally predictable and not even dangerous. "Here's something that we can talk about with certainty," Kritsky says. And here's one more thing that's certain: In 17 years, we'll be talking about it all over again.
The 17-Year Itch
In late spring, Brood X cicadas will emerge after 17 lonely years underground. They have just weeks to mate and lay eggs.
Cicada serenade
Males have a white, drumlike plate called a tymbal on either side of their abdomen, which they vibrate rapidly to make a variety of calls. Choruses can reach 100 decibels, as loud as a lawnmower at full bore. Females snap their wings in reply.
1 Immature cicadas live a foot or two underground, sucking sap from tree roots.
2 As their time to emerge nears, the nymphs use their legs to tunnel upward.
3 In April, the cicadas create openings at the bases of trees. Some feature little turrets of soil.
4 The cicadas emerge when the soil warms to 64 degrees, then cling to a tree to mature into winged adults.
5 After a mating frenzy, the female makes slits in a twig and lays eggs--a total of 400 to 600.
6 After a month, the eggs hatch. The young fall to the ground and dig in for a long wait.
[drawing labels]
Adult cicada
Tymbal
Eggs
Nymph
Brood X territory: Map of Eastern United States
Source: Ohio State University
Rod Little--USN&WR
This story appears in the April 19, 2004 print edition of U.S. News & World Report.