Overview

• Two distinct broods of cicadas, Brood XIII and Brood XIX, are set to emerge simultaneously this spring for the first time since 1803, in a rare event that only happens every 221 years.
• The dual emergence is expected to result in over one trillion cicadas appearing across a 16-state area, with the greatest numbers in forested regions and urban green spaces.
• The two broods are expected to overlap geographically in parts of central Illinois and eastern Iowa.
• Cicadas typically emerge once soil temperatures reach 64 degrees Fahrenheit, which could occur as early as late April, and the spectacle will likely continue through May and June.
• Scientists are curious to know whether the two groups will interbreed, which could possibly lead to the creation of an entirely new brood.