Insect Invasion!

Starting this month, more than a trillion insects will emerge from the ground like zombies. After tunneling out of the dirt, these cicadas (sih-KAY-duhz) will climb trees, walls, and other surfaces. They’ll shed their outer shells and spread their wispy wings. 

Most species of cicadas come out once a year. But this spring, two massive groups will arrive in the Midwest and Southeast. They’ve been underground since before most sixth-graders were born. Brood XIX emerges once every 13 years. The cicadas in Brood XIII appear only once every 17 years.

This spring will be the first time in 221 years that the two groups emerge at the same time. Just how long ago was that? Thomas Jefferson was president!

Crunch! A trillion cicadas will leave behind huge piles of outer shells on lawns, streets, and sidewalks. These hollow exoskeletons make a crunching sound when people step on them. But that’s not the only noise people will hear. 

A few days after they emerge, male cicadas will begin to make a shrill buzzing sound to attract females. The sound of millions of cicadas making their mating call can be louder than a rock concert. 

The female cicadas will cut holes into tree branches and lay their eggs inside. After that, their time will soon be up. All the adult cicadas in Broods XIX and XIII will die before summer arrives.

But their offspring, called nymphs, will live on. After hatching, they’ll fall to the ground and burrow into the soil. They’ll feed on sap from the roots of trees and plants as they slowly develop over the next 13 or 17 years. Then the cycle will start again.