While Illinois’ dual emergence of periodical cicada broods is harmless to people and animals, young trees may sustain serious damage if not protected by mid-June, experts at The Morton Arboretum said. 

This is the first co-emergence of these two broods since 1803, researcher Katie Dana from the Illinois Natural History Survey told Capitol News Illinois, making it a truly once-in-a-lifetime event. Although each brood will appear in 2037 and 2041, respectively, the 221-year-long cycle means the next time both broods emerge at the same time will happen in 2245. 

“I’ve heard reports of billions, I’ve heard reports of trillions and honestly, I think it’s somewhere in between those two,” Dana said of the number of cicadas that will emerge, “but that’s also a huge range.” 

That’s why researchers from the INHS are seeking the public’s help to photograph and record the 13- and 17-year-old cicadas they see with ecology apps such as iNaturalist or Cicada Safari. 

Dana said she is “trying to engage with citizen scientists” to help track the broods. 

“If you look back at like 2011 or 2007, when these broods last emerged, there (are) a lot of gaps in the mapping,” she said, “because it is really hard to get on the ground across the huge range that these broods are going to be out.” 

For information from The Morton Arboretum on periodical cicadas emerging, go to https://mortonarb.org/plant-and-protect/tree-plant-care/plant-care-resources/2024-cicada-emergence/ 

 draju@capitolnewsillinois.com 

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