Billions of cicadas are expected to buzz this spring with two broods emerging at the same time.
It’s the first time that scenario has happened since 1803, and it will not happen again for another 221 years.
Periodical cicadas have the longest known life cycle of any insect. Broods are groups of cicadas that share the same emergence years. Broods receive a number listed as a Roman numeral. Brood XIII only emerges every 17 years while Brood XIX emerges every 13 years.
The last time these two particular broods emerged together was when Thomas Jefferson was president, decades before Missouri statehood. The next event will be in the year 2245.
Emergence will occur in 18 Midwestern states. For the most part, most Missourians will only experience Brood XIX, the Great Southern Brood, which last appeared in Missouri in 2011. Expect them to emerge in late April to early May, according to University of Missouri Extension specialist Tamra Reall.
Those in northeastern Missouri near the Illinois border might see – and hear – both broods.
Cicada nymphs stay in the soil for 13 or 17 years, depending on their brood. They emerge when the soil warms to 64 degrees and dig their way out of the ground. They subscribe to the “safety in numbers” approach and emerge all at once. They climb trees, fence posts or anything vertical before shedding their hard skins. Then they head to treetops to mate, lay their eggs and die within four to six weeks.
Expect to see cicadas after a spring rain, and expect to see a lot of them – as many as 1.5 million per acre, says Reall. This creates a feeding frenzy for predators and litter so heavy that the sidewalks and highways may need shoveling.
Brood XIX, a 13-year brood, has four species. These will emerge late April through the second week of May.
Brood XIII, the Northern Illinois Brood, is a 17-year cicada with three species. It will appear in Iowa, Illinois, Indiana, Wisconsin and possibly Michigan in 2024. Expect emergence mid-May through June.
The loud sound you hear is from male cicadas as they send out their mating call, which can be as loud as a lawnmower and is unique to its species, Reall says. The synchronized male singing can be louder than a jet engine.