Cicadas to Emerge in Rare Double Brood Phenomenon In Late April Across The US

In 2024, a rare event will occur as both 13-year and 17-year cicadas will emerge simultaneously, a phenomenon not seen since in 1803.

Billions of cicadas are set to emerge in the Midwest and Southeast in late April.

The 2024 dual emergence of the 13-year and 17-year cicadas is a rare event, occurring once every 221 years, with adjacent groups Brood XIII and Brood XIX overlapping narrowly in central Illinois.

According to reports, Brood XIII and Brood XIX cicadas won’t synchronize their emergences again for another 221 years after 2024.

Brood XIII cicadas emerge primarily in the Midwest, centered in Illinois and extending into Wisconsin, Ohio, and Iowa. Meanwhile, Brood XIX cicadas are observed in a larger geographic area, spanning Missouri, Illinois, Louisiana, North Carolina, Virginia, and Maryland.

After 13 or 17 years underground, they surface for a noisy month-long mating ritual in spring when the soil temperature hits around 64 degrees Fahrenheit.

When these insects emerge, their large numbers contribute to a noisy mating frenzy. Emitting a high-pitched buzz or mating song, the sound can reach up to 100 decibels, similar to the noise of a jackhammer or motorcycle.

Despite being harmless to humans, the billions of emerging cicadas bring a brief, noisy period before completing their life cycles, leaving scattered carcasses on the ground.

Cicadas will continue to surface gradually in the Southeast and Midwest as temperatures rise through May and June. Upon reaching the surface, they shed their nymph exoskeletons, unfurl their wings, and take several more days for their adult skin to harden.

In a brief six-week lifespan, cicadas must navigate their mating ritual, lay eggs, and complete the cycle.

“By July 1st, they’re gone,” said Gene Kritsky, an entomologist at Mount St. Joseph University in Cincinnati.