Just did a search, found this image [1]. It looks like the geographical overlap is a small area in Illinois (light orange and brown regions in linked image).
Here's a better map [1] that shows the overlap better with sample data from the broods, it's an arc from Springfield to about Kankakee, about 120 miles.
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Just did a search, found this image [1]. It looks like the geographical overlap is a small area in Illinois (light orange and brown regions in linked image).
[1] https://cdn.britannica.com/32/222432-050-E9798FB1/map-emerge...
Here's a better map [1] that shows the overlap better with sample data from the broods, it's an arc from Springfield to about Kankakee, about 120 miles.
[1] https://cicadas.uconn.edu/broods/