Mount St. Joseph University

Biologists discover a new brood of periodical cicadas in Ohio and northern Kentucky

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File Under: biology, cicadas, gene kritsky

A 13-year brood of periodical cicadas has been discovered in southwestern Ohio and northern Kentucky, according to Gene Kritsky, Ph.D., professor of biology at the College of Mount St. Joseph.

Kritsky first suspected these cicadas may represent a previously unrecognized brood in 2001, but he had to wait 13 years to verify his hypothesis. When these insects started to emerge last Tuesday evening, it confirmed that Ohio was home to a 13-year brood.  This is the only 13-year brood of periodical cicadas in Ohio, which is home to four broods of 17-year cicadas.

Kritsky and Roy Troutman, another cicada researcher, mapped out the 2001 distribution noting specific locations to monitor this year. “You have to be patient to work with periodical cicadas,” Kritsky said. “When theses cicadas last appeared, George W. Bush had only been president for four months.”

Waiting over a decade to test a hypothesis is not unusual for periodical cicada researchers. Paul Dudley who lived near Boston in 1699, waited a total of 34 years to verify the 17-year cicada life cycle.

The oldest historical record of periodical cicadas corresponding to this year’s unrecognized brood was a newspaper account published in 1871. When they emerged in the early twentieth century, they emerged with larger better-known 17-year cicadas broods and were not recognized as a distinct population.

This year, 13-year periodical cicadas were expected to emerge as part of Brood XXII in Louisiana and Mississippi. Kritsky and Troutman are anxious to determine the relationships, if any, between the southern population and the Ohio Kentucky population.  “It may be a relict of a once larger population or the subsequent evolution of a new brood that coincidentally emerged the same year as Brood XXII,” Kritsky said.

Kritsky and Troutman are asking the people in southern Ohio and Northern Kentucky to help with the mapping project by turning their smart phones location services or GPS functions, taking a photograph of the cicadas and e-mailing it to the researchers via the website

The emergence will take two to three weeks to reach its peak. Those wanting to see this new brood can visit Crooked Run Nature Preserve and the Chilo Lock 34 Park in Clermont County, Ohio during the first two weeks in June or will wait until they emerge again 2027.

The College of Mount St. Joseph is an undergraduate and graduate Catholic college that provides an interdisciplinary liberal arts and professional curriculum emphasizing values, service and social responsibility.

Image caption: Thirteen-year periodical cicada nymphs emerging at the Crooked Run Nature Preserve in Ohio.  Photography by Roy Troutman.