When do cicadas leave Illinois?
With reports of live cicadas winding down and sightings of the dead insects on the increase, many people wonder what's coming next. Here's what to expect.
When do the cicadas go away?
The remaining periodical cicadas out now should be gone by late June. Periodical cicadas are among the longest-lived insects on the planet, but most of their 13- or 17-year lifespan is spent underground. After emerging, singing and reproducing, the adults don't live long. After about a month, the cicadas begin to die.
Their departure can be memorable. In 1990, there were reports of people in Chicago using snow shovels to clear sidewalks of dead cicadas, which have a noticeable odor.
More: Is your dog eating cicadas? Here's why you should be worried about it
Do cicadas come out every year?
Some cicadas do show up every year. Annual — or dog-day — cicadas emerge during the heat of summer, usually around July, said Kacie Athey, a specialty crops entomologist with the University of Illinois Extension.
The periodical cicadas that are dying off now were part of a historic dual emergence of two particular broods, an event that hadn't occurred since 1803 and made Illinois the center of attention for cicada watchers. In some years, no periodical cicadas emerge. After 2024, Brood XIII and Brood XIX cicadas won’t sync up their emergences again until the year 2245.
More: What animals eat cicadas?
Do cicadas have a purpose?
Cicada nymphs aerate the soil. The emergent adults prune mature trees and provide an abundant source of food for wildlife — and some humans. After they die, cicadas' bodies provide a source of nitrogen for growing trees. CicadaMania.com breaks down the bugs' many benefits.
This article originally appeared on Journal Star: When are the cicadas leaving Illinois?
