While parts of the U.S. are already seeing cicadas emerging in dramatic numbers, in the Chicago area, some are seeing early signs of an emergence, while others have remained relatively quiet.
So, is that a sign that the emergence won't be as bad as expected?
According to experts, the real cicada peak has yet to arrive. And once it does, one thing has to happen before you hear the sounds many have spent months anticipating.
"The periodical cicadas will start emerging when the soil temperature eight inches below the ground gets to 64 degrees," Jennifer Rydzewski, an ecologist with the Forest Preserve District of DuPage County, told NBC Chicago.
The Forest Preserve District of DuPage County posted a picture on Facebook Monday, showing cicadas shells hanging from a fence at an area under construction at the Willowbrook Forest Preserve in Glen Ellyn. The shells are the first sign of cicadas' arrival. When cicada nymphs first come out from the ground, they climb up to a tree or another high place and shed their shells.
"I am guessing because this black fencing is radiating the heat onto the bare soil…It's getting a little bit warmer down in this area, which is why we are seeing a little patch of these cicadas emerging right here," Rydzewski said, noting that other locations will likely see stronger emergences "within the next few days."
"It's getting really close," she said.
Local
Several reports of cicadas beginning to sprout from the ground have surfaced in recent days, and photos on social media showed trees covered in cicadas in parts of Illinois.
Feeling out of the loop? We'll catch you up on the Chicago news you need to know. Sign up for the weekly Chicago Catch-Up newsletter.
The emergence has started earlier than average in Illinois, but much of the region has yet to see the swarms of cicadas being warned about and the defeaning sounds that have sparked 911 calls in some states.
According to some experts, the emergence of the first cicadas came about two weeks ahead of the historic average. It will continue to be sporadic, however, as soil temperature, mulch and turf grass all impact cicadas differently. For example, the soil is warmer near pavement, so cicadas in the those spots are expected to emerge quicker.
Experts with the Insect Asylum estimated peak emergence would arrive in mid-May for the Chicago area.
The ideal soil temperature for cicadas is 64 degrees, but a rise in humidity levels can also play a role, the Insect Asylum reported.
"Research shows that the particular night of the periodical cicadas’ emergence depends on soil temperature," a post from the National Weather Service said. "Cicada juveniles, or nymphs, emerge after a rainstorm when the soil temperature at 8 inches in depth exceeds approximately 64°F."
In a year of full emergence, after the bugs surface, they then begin mating, which is often met with the noise most associate with cicadas. Experts with the DuPage Forest Preserves said it takes about a week from emergence before cicadas begin mating, however.
Cicadas have a lifespan of approximately four weeks, meaning the emergence is set to last through at least mid-June.
The historic 2024 emergence will see two broods of cicadas emerging in a moment that hasn't been seen in more than two centuries.
"This is like the year for Illinois," cicada expert Catherine Dana, an affiliate with the Illinois Natural History Survey, told NBC Chicago. "We are going to have cicadas emerging all over the state."
The two emerging broods are Brood XIII and Brood XIX, which haven't emerged simultaneously in 221 years.
For the Chicago area, Brood XIII will be most seen in parts of northern Illinois and Indiana, and possibly even in Wisconsin and Ohio, Dr. Gene Kritsky, dean of Behavioral and Natural Sciences at Mount St. Joseph University in Cincinnati, said.
The Northern Illinois Brood itself is huge, with a reputation for the "largest emergence of cicadas anywhere," according to the University of Illinois.
Meanwhile, Brood XIX, or the Great Southern Brood cicadas, have a more widespread population, covering parts of Missouri, Illinois, Louisiana, North Carolina, Virginia and Maryland.
"Brood XIX is arguably the largest (by geographic extent) of all periodical cicada broods, with records along the east coast from Maryland to Georgia and in the Midwest from Iowa to Oklahoma," the University of Connecticut reports. "Although 13-year cicadas are generally considered to have a southern distribution, the northernmost known record of this brood is in Chebanse, IL, roughly 75 miles from Chicago’s Loop."
Across most of Illinois and the Chicago area at least one of the two broods is likely to emerge, but in a narrow part of the state, both could emerge at the same time, in the same place.
"Somewhere around Central Illinois, probably like around Springfield, is what some researchers are predicting we may see some overlap of these two ... different broods," Dana said. "It's not going to be a large area. But there will likely actually be some mating happening between these two broods, which is going to be really exciting."
Here's a map of what to expect in Illinois, according to data from the USDA Forest Service.
