17-year cicada brood emerging, say biologists
The cicadas are coming! The 17-year brood is now emerging in Central Pennsylvania.
Posted June 6, 2008
LEWISBURG, Pa. -- Two Bucknell University biology professors who specialize in the study of insect life say Pennsylvania is about to be invaded.
The first wave of red-eyed cicadas are just beginning to emerge from their 17-year subterranean life.
Evolutionary biologist Steve Jordan was riding his bike on Route 192 toward R.B. Winter State Park in central Pennsylvania on May 30 when he noticed the first red-eyed cicadas.
It was a thing of beauty, he said.
"Cicadas are one of America's biological treasures," said Jordan, who has also studied damsel flies in French Polynesia. "They're an example of the biological richness in America. They're a native species. They're unique. We should be proud of them and take joy in them."
Warren Abrahamson, a professor of biology at Bucknell who specializes in studying plants and insects, lives 10 miles east of the place where Jordan spotted his first sleepy cicada. Abrahamson has yet to see his own periodical cicada (genus Magicicada) this year, but he can't wait.
"The cicadas are a phenomenon. They live for 17 years underground, then emerge out of the soil and have this incredible frenzy," he said. "It involves all those marvelous things — emergence, shedding one's skin, becoming an adult. It's sex. It's females going crazy injecting eggs into the terminal buds of plants."
Abrahamson well remembers the last time the cicadas tunneled out of the ground in 1991. Growing up in Michigan, he had never seen a periodical cicada before. His dog found the first shed skin in the forest understory, then suddenly, "the entire leaf litter was moving. Within a few days, the sound of their song became so loud that you had to speak up in order to be heard over the din of the cicadas calling to each other. It was incredible."
The periodical cicada is often referred to as the "17-year locust," although this is a misnomer. Early American colonists thought that cicadas were the Biblical locusts (which are actually a species of grasshoppers), and the name stuck.
Cicadas, said Jordan, are more closely related to aphids than grasshoppers. Pennsylvania cicadas emerge in 13- and 17-year cycles. These “broods” were assigned Roman numerals in 1893.
Eight different broods
In Pennsylvania, eight different broods emerge across the state. The cicadas that Jordan has seen and Abrahamson hopes to see soon belong to brood XIV. The cicadas are easily recognized by their stunning red eyes, sleek black bodies, and translucent orange wings. They often appear in large numbers, up to tens of thousands in one swarm. They do not sting or bite, but they do need to feed on plant fluids to survive.
Abrahamson said that they do damage the ends of trees, but it's minor, and "you won't even notice it next summer."
The last time the cicadas emerged, the Internet was in its nascent stages. Today, Jordan said, the Internet can be used to encourage everyday people to participate in cicada sightings. He pointed to a Web site created by his colleague and world cicada expert John Cooley at the University of Connecticut.
The site was developed by a grant from the National Geographic Society to help track cicada distribution. "The maps that have been used since the 19th century are old and inaccurate," said
But hurry, by July, the cicadas will be underground snacking on root sap again for the next 17 years.
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