Cicadas Are Here: Nine Facts About the Brood X Emergence
Swarms of Brood X cicadas emerge once every 17 years
by Alexa Corse
Updated May 29, 2021
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Soil to Sky
Billions of cicadas—members of what scientists call Brood X—are now emerging in parts of the eastern U.S. after living underground for 17 years.
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Matter of Time
After emerging from underground, cicadas position themselves on a vertical surface and shed their exoskeletons to become winged adults. Adult cicadas mate and die within weeks.
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Prime-Number Life Cycles
Some periodical cicadas emerge after 17 years, while others emerge after 13. Those prime-number life cycles may help protect cicadas by making it hard for predators to sync up their life cycles with the insects.
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Safety in Numbers
Many cicadas still fall victim to predators, but enough survive to produce a new generation— with females laying about 400 to 600 eggs.
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Snack Time
Cicadas are edible, and people collect them for use in everything from salads and smoothies to tacos and cookies. Experts say people who are allergic to shellfish should probably avoid eating cicadas.
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Bugged Out
Though periodical cicadas are known for their two big red eyes, they also have three small eyes in between. Some cicadas have eyes that are blue or some other color.
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Risk to Young Trees
Some gardeners protect young trees by wrapping them in netting to keep cicadas from depositing eggs in the branches.
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They Don’t Bite
Cicadas don’t sting or bite and pose no threat to humans. But their sheer numbers can make the flying insects hard to avoid in some areas.
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Seen and Heard
The mating calls of male cicadas can be louder than a lawn mower. Males produce their calls by vibrating drum-like organs on their abdomen.