New cicada brood coming soon, scientists say

Unlike most individuals, who would normally avoid bugs, two local scientists have been waiting 13 years for the arrival of a brood of cicadas.

Gene Kritsky, professor and chairman of biology at the College of Mount St. Joseph, and fellow cicada researcher Roy Troutman claim they discovered a group of cicadas in Southern Ohio and Northern Kentucky that emerge every 13 years.

It's a discovery they say will silence naysayers.

"He and I mapped these cicadas out, and I then predicted … (that) in 2014 we were going to have a 13-year emergence and that seems kind of nice, but none of my colleagues believed me," Kritsy said. "So for the past 13 years, I've been waiting patiently to show everybody that, yes, we do have (13-year periodical) cicadas here in Cincinnati."

Periodical cicadas, as opposed to annual cicadas, are found only in the eastern half of the United States and emerge typically every 13 or 17 years, Kritsky said. The groups that emerge are called broods, and each brood is numbered.

There are only three known 13-year broods, and Kritsky says the emergence of cicada nymphs Tuesday at the Crooked Run Nature Preserve in Clermont County marked Ohio as home to one of them. The 13-year periodical cicadas are called Brood 22.

Cincinnati is also home to Brood 10 and Brood 14, which Kritsky thinks played a role in masking Brood 22 for so long. "These cicadas didn't come out of nowhere. They've always been here," he said. "One of our librarians at the Cincinnati Public Library a couple years ago emailed me a news clip from 1871 saying there were cicadas."

That was the first historical record of this newly-recognized brood. People noticed it through the years but never realized it was different until now.

"Back in 2001 I received an email from an individual in Falmouth, Kentucky … (saying) that they had cicadas, and that did not correspond to any of the broods in that area," he said. "That's when I thought they were a 13-year brood."

Kritsky had seen the cicadas before, in 1988, but he and other biologists thought they were a different brood that was a year late.

So he started digging.

Brood 22 emerged in 1923, he said, "but that was a Brood 14 year, so everybody thought they were Brood 14."

In 1962, officials had to halt construction of the Meldahl Locks and Dam to clean off hordes of cicadas. But no one thought to report them. In 1975, they emerged again, but Kritsky said it again corresponded with another brood.

Kritsky and Troutman formed their hypothesis in 2001, but they had to play the waiting game to see if they were right. "If I was working on fruit flies, I'd have this done in a month," Kritsky said.

Joshua Benoit, an assistant professor in the Department of Biological Sciences at the University of Cincinnati, said it is common for broods to stay hidden among the emergence of other broods.

"A lot of times they'll emerge with another brood, so some of these get missed," said Benoit, who focuses his studies on general insect physiology. "You have to have them two times in a row like that.... When it happens twice you have the presence of a brood."

Periodical cicadas have evolved to emerge every 13 or 17 years partially as a defense mechanism, Kritsky said. No predators emerge at intervals like that, and any other predators that might enjoy a nice cicada snack are overwhelmed by their vast numbers.

"Their survival strategy when they do come out is to come out in such great numbers that their predators get tired of eating them," Kritsky said.

Cicadas come in hordes, and any sort of predators that do take interest cannot dent their population.

"If you walked out of your house and found the world inundated with flying Hershey kisses, you could eat and eat and eat (but you wouldn't made a dent), and that's basically what they are doing," he said. "They're overwhelming their predators and still having enough to reproduce and to supply the next generation."

The emergence of this brood will take about two weeks, Kritsky said. Residents can help map the cicadas by turning on their phone's GPS functions and sending pictures of the insects to Kritsky and Troutman via www.msj.edu/cicada.

"If people really want to see these things, they should wait about two weeks because the cold weather is slowing them down a little bit," Kritsky said. "In about two weeks they'll be out there singing and screaming."