for National Geographic News
Brood X has arrived. Are you ready?
Billions of black, shrimp-size bugs with transparent wings and beady red eyes are beginning to carpet trees, buildings, poles, and just about anything else vertical in a wide region of the U.S. The invasion zone stretches from the eastern seaboard west through Indiana and south to Tennessee.
The message board on the Cicada Mania Web site, managed by Dan Century in Metuchen, New Jersey, was abuzz Tuesday with news of cicada sightings.
Dan from Silver Spring, Maryland, wrote: "Our 60 year old house and the surrounding yard are now covered with them. It was quite amusing watching my wife (who has never experienced the cicada before) sprint to her car with an umbrella over her head."
Angie in North Springfield, Maryland, wrote: "Their little carcasses are stuck to my walls. I swept away about a dozen off the front porch yesterday. I awoke this morning and one of my large Hosta plants in the back yard is covered."
"dp" in Potomac, Maryland, wrote: "I saw about 3 cicadas this morning!! But all yesterday evening my pup was going nuts digging everywhere. He was on a serious excavating mission!! They are coming. He is excited but has no idea that his totally unsupervised backyard playtime has ended for a few months!!"
By the end of June the cicadas will be gone, not to be heard from or seen again for 17 years.
The bugs belong to the largest group, or brood, of periodical cicadas—insects that spend most of their lives as nymphs, burrowed underground and sucking sap from tree roots. They emerge once every 17 years, transform into adults, do the business of reproduction, and then die.
The cacophony of their courtship ritual disturbs suburban tranquility, and their nests can kill young tree branches. Females make slits in the branches and deposit their eggs inside. The process leaves many treetops with brown, dangling limbs flapping in the wind.
In addition to being a nuisance, the mass emergence aerates the soil, provides a feast to thousands of predators, prunes the treetops, and provides a pulse of nutrients into the environment, scientists say.
There are at least 12 broods of 17-year cicadas plus another three broods that emerge every 13 years. "A brood is a class year, like the graduates of 2004 who will be graduating this May," said Gene Kritsky, a biologist and cicada expert at the College of Mount St. Joseph in Cincinnati, Ohio.
A brood emerges almost every year somewhere, sometimes overlapping with others. But none of the emergences matches the pure size of Brood X, which includes three cicada species: Magicicada septendecim, Magicicada cassini, and Magicicada septendecula.
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