By Kathleen Berger
As thoughts of summer fade away, they are replaced by everything fall! When clearing out those flower beds, the presence of cicada cascaras may bring back memories of the summer of the historic cicada emergence.
Into the fall months, scientists in St. Louis review the data and share discoveries about the historic double emergence of cicadas in the summer of 2024.
“Total shock to us,” said entomologist Sara Miller, PhD, assistant professor at the University of Missouri-St. Louis. “We weren’t finding cicadas through most of north St. Louis, we weren’t finding them in areas of the city that were quite old. And then just to find tons of them in this very new forest.”
That forest is the location of the failed Pruiit Igoe housing complex. Historically, the Pruitt-Igoe complex was meant to provide new, improved public housing for a community struggling with overcrowding in the 1950’s. Yet, design flaws and lack of funding for maintenance led to increased vacancy rates and crime, leaving the complex uninhabitable just 20 years later. Once demolished in 1976, the site remained vacant until the 1990s when it became a demolition landfill.
“There’s been quite a forest that has developed in the area where the project was taken down, and it’s filled with cicadas,” said Miller. “And it has served as sort of a source population for recolonizing parts of north St. Louis.”
This is a surprise compared to other parts of north St. Louis city with older developments and abandoned or torn down structures.
“Especially in these older portions of the city where we would have continual development, almost from when the city was founded,” she said. “So, these periodic cicadas have these really long 13-year life cycles. They need to be in this habitat that’s not disturbed over these 13 years.
For a better understanding of the history and ecology, UMSL entomologists Aimee Dunlap and Sara Miller dived into cicada research.
“We were interested in this intersectionality of the history of the development of St. Louis, with where cicadas are or are not,” said Miller.
Miller explained how they conducted their research in a new and creative way.
They recruited citizens in the St. Louis area to be involved in the project, by using an app. This would help UMSL researchers, who were going out into the communities and green spaces in St. Louis, cover more ground.
“We have this double emergence cicada, natural history event and maybe this is a way to get people who otherwise would not be as interested or excited about insects. We managed to get more than 800 observations. I had emails. It’s just been really gratifying to see people so excited about insects.”
Miller said the project became quite an accomplishment for cicada mapping.
“With the hope that to be able to spend three minutes would be really quick and easy and we can get a bunch of people to collect a lot of data.”
The research team made discoveries about user locations and the cicada activity.
“What were the distribution and can we say anything about how the development of the St. Louis region interacts,” Miller said.
The study showed the importance of green spaces. In the failed Pruiit Igoe space,
Miller said the success of cicadas is unexpected and fascinating.
“It was such an urbanized environment. To find this pocket of habitat in Pruitt Igoe, and then grow to such high densities and then start recolonizing the city, was a surprise.”
But with any possibility of redeveloping the property, the cicada’s future is uncertain.
“We suspect, maybe in 13 years, a lot of that forest or maybe all of that forest may be converted to new developments. So what will become of cicadas then? Cicadas are not a conservation concern. They are really great for ecosystems.”
Studying cicadas will help the entomologists’ mission.
“We are actually in an insect biodiversity crisis at the moment,” Miller said. “Insects, as a whole, are not doing very well. The numbers are declining, we don’t really know why. And so the way that cicadas can help us is that they are a way of getting people excited about insects.”
