If you’ve spent any time outdoors the last few days, you may have heard the rhythmic buzzing — or screaming — of cicadas beginning to emerge from the ground. For the first time in 221 years, more than one million cicadas will emerge simultaneously throughout the country.

Deemed a rare emergence, two broods of cicadas are making their way to the surface this summer. The largest brood, known as Brood XIX, appears every 13 years and Brood XIII emerges every 17 years. The two broods haven’t emerged in the same year since 1803 and won’t again until 2245.

Southwest MO to see only one brood

Broods XIX and XIII will appear in 17 states this spring and summer: Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Wisconsin and Virginia. However, not all states will see an overlap of the broods.

When it comes to “Cicadageddon” in Missouri, only counties in the northeast part of the state will see members of both broods. In southwest Missouri, folks will only experience buzzing from Brood XIX, which hasn’t emerged since 2011.

In addition to Missouri, Brood XIX stretches from southern Iowa to Oklahoma, through the southern coastal states and as far east as Washington D.C.

When will they emerge, when will they leave?

The emergence of cicadas is dependent on weather, when soil 8 inches below ground reaches 64 degrees Fahrenheit. In Missouri, this tends to be mid-May. Folks throughout the state of Missouri have likely already seen a few of the critters out and about.

The lifespan of a cicada is typically four to six weeks, so the insects will begin to die off in late June.

What do Brood XIX cicadas look like?

Unlike annual cicadas, which are greenish in color, Brood XIX cicadas have black bodies, orange markings, clear wings and red eyes. Brood XIX cicadas can grow 1-2 inches in length and have a wingspan of 3-4 inches.

How do cicadas make that distinctive buzzing sound?

Cicadas are considered one of the loudest insects, buzzing up to 90-100 decibels. But it’s only male cicadas that make that distinctive buzzing sound. Female cicadas do not have the necessary sound-producing organs.

Male cicadas have two vibrating membranes called tymbals that sit behind each wing. Each tymbal contains a series of ribs that bend and make clicking sounds when a male flexes its muscles. Cicadas repeat this movement 300-400 times per second, which result in the unique buzzing sound.

Two eardrums are also responsible for carrying the sound. By tightening the muscles around their eardrums and extending their abdomens, cicadas can alter the volume and pitch of their sound. The abdomen of a male cicada is almost entirely hollow, which helps to amplify these sounds.

Though female cicadas cannot make these sounds, they respond to male cicadas with the flicking of their wings.

Do cicadas bite or sting?

Cicadas are harmless to humans and pets; they do not bite or sting. If you decide to pick one up, their prickly feet make poke your skin, though.

Cicadas can, however, be dangerous to young trees, as cicadas lay their eggs on small tree branches. To protect young saplings, cover them in a mesh or netting to keep the cicadas out.

What’s the difference between cicadas and locusts?

Though both are large and loud, cicadas and locusts are two different species of insects. Locusts belong to the same family as grasshoppers and are more destructive, feeding on much plant life. Though cicadas lay their eggs in trees, they do not chew leaves or harm crops. They only drink tree sap.

Greta Cross is the trending topics reporter for the Springfield News-Leader. She has more than five years of journalism experience covering everything from Ozarks history to Springfield’s LGBTQIA+ community. Follow her on X and Instagram @gretacrossphoto. Story idea? Email her at gcross@news-leader.com.