There will be billions of them when they emerge. These insects are clunky fliers and easy prey. But if billions of them show up, even if millions get eaten, there are still plenty of cicadas left over to mate and lay eggs again.
Kritsky said this year is an opportunity for him to get a sense of where the cicadas in Brood X are emerging, because while there are cicada sightings that go back hundreds of years in the U.S., the maps have not always been good as to where cicadas are. Some scientists are also concerned periodical cicadas may be in danger, he said, because at least one brood of these cicadas – Brook XI – has died out.
Kritsky is asking people to download the app that Mount St. Joseph’s University developed, called Cicada Safari, to take photos of the periodical cicadas and track where they are emerging.
Cicada Safari is available for both iPhone and Android.
The photos help Kritsky and his team map broods. He said it can be difficult for one person, or even a team of people, to map broods in a traditional way.
“Case in point: last year, when Brood IX emerged, we discovered that four other cicada broods had emerged off-cycle,” Kritsky said. “And we might not have found that if we’d used the protocol we’d used in the past, where we would go down to where we knew the cicadas were and mapped them out.”
Kritsky said the app is something kids and parents can do together. Go to a park or a cemetery, or somewhere the app suggests that usually has periodical cicadas or older trees, and upload photos of the cicadas you find to the app, he suggests.
“I see this as an opportunity to get your kids interested in natural history and observation,” he said.
Don Cipollini, a biology professor at Wright State University, said he is planning several experiments around when the 17-year cicadas emerge.
Periodical cicadas lay their eggs in trees before they die. Once the eggs hatch, the nymphs will fall out of the branches and into the soil, where they feed on the roots of the tree.
A map of where cicadas are expected to emerge this summer. Courtesy of Gene Kritsky, Mount St. Joseph's University.
While that generally doesn’t hurt older trees, younger trees and trees that bear fruit can be hurt by the egg-laying process.
Cipollini said he plans to study if birds, which eat cicadas, can be a visual deterrent for cicadas laying their eggs in small trees, by placing cardinal decoys in some trees in a plot of trees he already has for other research.
Cipollini also studies emerald ash borers, which are an invasive species killing ash trees in Ohio. Periodical cicadas are native to the area.
Cipollini said he wanted to see if the damage caused by periodical cicadas when they lay eggs in young ash trees affects the damage that emerald ash borers can do to young ash trees.
He said he also wants to see if he can study the fate of dead cicadas. Once the cicadas die, there are often billions of them decomposing on the ground. He wants to see to what extent that decomposition fertilizes young trees.
Cipollini said the interest kids can have in cicadas can help people get over their fear of bugs.
Cipollini said part of the reason he is now interested in cicadas is because he was about seven years old the first time he saw periodical cicadas come out of the ground.
“It just hit right at the right time, right at this impressionable time for me, that I always remembered that I was fascinated by it,” he said.