The historic 2024 emergence of cicadas in the upper Midwest is now underway, but with the emergence of two broods of cicadas this spring, some groups are urging residents to celebrate their arrival, rather than being fearful or nervous.
The two emerging broods are Brood XIII and Brood XIX, which have not emerged simultaneously for 221 years. Although cicadas cause a lot of noise and leave behind many shells, they can actually be beneficial in more ways than one.
According to American Humane, cicadas are “essential” to habitats and provide benefits to ecosystems in the Midwest. These benefits can include natural soil aeration, with cicadas tunneling and digging channels opening channels for air, water and nutrients to reach plant roots.
Cicadas that emerge this year will die once they finish breeding, helping to fertilize the soil and provide food for a wide variety of animals, the group says.
Although some cicadas can cause damage to young trees and plants, they can also help prune existing plants and trees, according to the group, allowing them to produce more flowers and fruit in years to come.
For the Chicago area, Brood XIII will be most visible in parts of northern Illinois and Indiana, and perhaps even Wisconsin and Ohio, said Dr. Gene Kritsky, dean of behavioral sciences and natural studies at Mount St. Joseph University in Cincinnati.
The northern Illinois brood itself is enormous, with a reputation for “the largest cicada emergence in the world,” according to the University of Illinois.
Meanwhile, Brood XIX, or Great Southern Brood cicadas, have a more widespread population, covering parts of Missouri, Illinois, Louisiana, North Carolina, Virginia, and Maryland.
Join Stefan Holt, Brant Miller and more from NBC Chicago to prepare for the emergence of the Cicada in 2024.
“Brood in Oklahoma,” reports the University of Connecticut. “Although 13-year-old cicadas are generally considered to have a southern distribution, the northernmost known record of this brood is in Chebanse, Illinois, approximately 75 miles from Chicago’s Loop.”
In most of Illinois and the Chicago area, at least one of two broods is likely to emerge, but in a narrow part of the state, both could emerge at the same time, in the same location.
“Somewhere in central Illinois, probably like around Springfield, some researchers are predicting that we might see some overlap of these two different broods,” Dana said. “It won’t be a big area. But there will probably be some mating between these two broods, which will be really exciting.”
Here’s a map of what to expect in Illinois, according to data from the USDA Forest Service.
The emergence began earlier than average in Illinois, but for those wondering when the region might see swarms of cicadas and the failing sounds that have triggered 911 calls in some states, this timing is not not arrived yet.
According to Insect Asylum experts, peak emergence should occur in mid-May in the Chicago area.
Sightings have already been reported so far, but many factors will determine when the cicadas start emerging en masse from the ground.
Cicadas typically emerge when the ground begins to warm in spring and early summer, which is between mid-May and late June.
“The periodical cicadas have been emerging for the last week and a half,” Stephanie Adams, a plant pathologist at the Morton Arboretum in Lisle, said Tuesday of Brood XIII, which will soon spread throughout the Chicago area. “We found them both here in our landscape and also in our eastern woods.”
According to Adams, the emergence of the first cicadas occurs about two weeks earlier than the historical average. This will continue to be sporadic, however, as soil temperature, mulch, and turf all impact cicadas differently. For example, the ground is warmer near sidewalks, so cicadas in those locations should emerge more quickly.
The ideal soil temperature for cicadas is 64 degrees, but increased humidity can also play a role, the Insect Asylum reported.
Cicadas have a lifespan of about four weeks, meaning emergence should last until at least mid-June.
“Research shows that the night of emergence of periodical cicadas depends on soil temperature,” a National Weather Service article states. “Juvenile cicadas, or nymphs, emerge after a rainstorm when soil temperatures 8 inches deep exceed about 64°F.”
NBC Chicago
