After developing underground for 17-years, a swarm of buzzing cicadas will soon emerge across eastern Ohio.
A lot has changed since they were last here in 1999, including the emergence of citizen scientists.
Teenage insects enter adulthood
Cleveland Metroparks naturalist Mark Warman is digging cicada larva out of a dirt-filled dish. Known as nymphs, they lumber across his hand.
“This is a 17-year-old insect that I’ve got in my hands right now, and this is like a senior in high school.”
Soon it will shed its youthful exterior and emerge as a full-fledged adult, part of a phenomenon unique in nature.
The 17-year cicada, called periodical cicadas, are found only in the eastern US. A 13-year cousin lives in Southern states.
A patchwork of twelve populations, called broods, emerge in succeeding years from the Mississippi to the Atlantic state.
This year it’s Brood V’s turn, arriving in eastern Ohio, parts of West Virginia and patches of Virginia and Maryland.
As adults, these bumbling, teen-age nymphs will find their voice…
The ancient mysteries of Magicicada
Emerging in their millions, it’s one of the loudest sounds in nature - louder than a landing jet.
The 17-year-cicada has baffled scientists and intrigued people since the time of the pilgrims.
William Bradford, governor of the Plymouth Colony, was among the first Europeans to describe them, when after the 1633 emergence he wrote, “they made such a constant yelling noise as made all the woods ring of them.”
The Pilgrims, reminded of the biblical plague, called them locusts - a misnomer that still pops up today.
Their scientific name is Magicicada, playing off their magical, Methuselah-like powers.
An Ohio observer was the first to figure out their 17-year cycle.
Dr. S.P. Hildreth in 1812 detailed Brood V’s emergence in his home town of Marietta, exactly 17 years after they were seen there in 1795.
2016 is just the latest in three million years of 17-year cycles for these enigmatic insects.
The evolution of the prime number cycle
“That’s one of the great mysteries of biology,” says Gene Kritsky, who teaches biology at Mount St. Joseph College in Cincinnati and has been tracking periodical cicadas for 40 years.
He says the answer may involve math.
“The benefit of having a 17 year life cycle is that it’s a prime number, and having a prime number life cycle makes it pretty difficult for a predator to evolve synchrony with a specialized life cycle like that.”
The benefit is that the cicadas come out in such huge numbers every 17 years, that no matter how matter bugs get eaten, there are still millions more to carry on the line.
“A good analogy that I’ve used before is that if you walk outside and find the world swarming with flying Hershey’s kisses, humans would eat a lot of them," says Kritsky, "but eventually we would get tired of eating them.”
And this year cicada scientists are converging on Ohio, not to eat them, but to map the Brood V emergence.
Mapping the 2016 Brood V
Leading the effort is John Cooley, who teaches biology at the University of Connecticut.
He says the key to unlocking the mystery of cicadas’ unique lifestyle, is by better understanding how all the broods fit together.
Cooley says that our attempts to understand the evolution of the 17-year life cycle, “are kind of stuck until we have a better idea where the different broods and the different species are found.”
Ohio’s Brood V includes three separate species of 17-year cicadas and Cooley and his team of citizen scientists will be diligently mapping them by listening to their unique songs.
Roy Troutman is a master cicada tracker from the Cincinnati area.
“My ears are attuned to the sound," says Troutman, "and if I hear a cicada no matter what species, it’s just like automatically I can hear it in the background.”
As a citizen scientist, he’s helping Cooley pinpoint where each species occurs in Brood V.
Cooley is eager to hear what citizen scientists in northeast Ohio discover.
“So it will be a good question to see whether we have all three species going all the way up to the top of the brood.”
And that’s where Cleveland Metroparks naturalist Mark Warman comes in.
He’s leading the effort to engage the public in the mysteries of magicicada in helping fill-in gaps in maps from the last time they were here in 1999.
“We don’t have that granular, or that detailed level of information, and that’s really what we hope to capture in this emergence, says Warman.
"Are they in your backyard? Are they in the park near your home? Take a picture, share it with us, or fill out our cicada reporting form.”