Swaths of the United States will experience the rare emergence of two massive adjacent broods of periodical cicadas, with more than a trillion buzzing insects coming out of the ground in April.
Brood XIII, which has a 17-year cycle, will appear in parts of Illinois, Iowa, Wisconsin and Indiana, while Brood XIX, on a 13-year cycle, will be found in 15 Midwestern and Southern states, with the two groups overlapping in only a small section of central Illinois. They arise together once every 221 years.
Periodical cicadas—different from annual cicadas, which emerge on a staggered basis during any given year—spend either 13 and 17 years underground, with groups sharing the same life cycle arriving together between April and June. Once out of the ground, the adult male cicadas attract females with a loud hum, the pitch, tone, frequency and volume differing between individual species.
Out of the more than 3,000 species of cicadas across the globe, just nine are periodical. Of those, only seven are found in North America. Broods XIII and XIX last emerged together in 1803 and won’t again until 2245.
