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AUBURN UNIVERSITY, Ala. – If you’re from the south, the familiar humming from this summer bug probably sounds just like home. With their prominent eyes and green sheen, cicadas can be seen in rural and urban environments across the southeast.

What are Cicadas?

According to Alabama Extension specialist Katelyn Kesheimer, cicadas are large insects in the order Hemiptera, which are true bugs. The bugs appear annually in the spring and summer wherever hardwood trees grow.

“Cicadas are harmless insects,” Kesheimer said. “They do not bite, sting or transmit any diseases.”

The high-pitched sound emanating throughout the day comes from the males. The males vibrate membranes on their body to attract females.

Females do not make any sounds. Adult cicadas will mate about one week after emergence.

After mating, females will lay eggs on twigs of more than 200 types of trees. After six weeks when it is time for the eggs to hatch, the nymphs—or immature cicadas—will drop to the ground and move into the soil.

They will feed on tree root sap as they molt and mature, until they emerge as adults.

Cicada Variations

According to Kesheimer, there are two types of cicadas: annual—or dog-day cicadas—and periodical cicadas.

Like the name suggests, annual cicadas come out every year while periodical cicadas come out every 13 or 17 years.

Therefore, periodical cicadas spend most of their life underground and only emerge as adults for about a month.

“Periodical cicadas are successful because they emerge in such large numbers that they overwhelm predators,” Kesheimer said. “On the other hand, annual cicadas emerge every year in small numbers and don’t have the advantage of overwhelming numbers.”

This makes annual cicadas better adapted to hiding in trees and moving quickly to avoid predation.

The Year of the Cicada?

All over the news and social media, reports of the emergence of the Brood X cicadas left several calling this the year of the cicada.

“Brood X is a group of 17-year periodical cicadas that emerged in the eastern United States in 2004,” Kesheimer said. “They have spent the last 16.5 years underground and are set to emerge again.”

Once they emerge, mate and lay eggs, the newly hatched nymphs will return to the soil and emerge again in another 17 years.

So, what makes the emergence of these Brood X cicadas so significant?

There are large emergences of periodical cicadas across the United States in 13- or 17-year intervals. However, Brood X is one of the largest broods of the 17-year cicadas that we have.

Brood X will emerge from north Georgia all the way up to Pennsylvania.

“Unfortunately, Brood X cicadas will not be emerging in Alabama in 2021,” Kesheimer said. “The next emergence of a brood in Alabama will be in 2024 when Brood XIX emerges after 13 years.”

Whether you’re experiencing the emergence of the Brood X cicadas or not, you’re sure to hear at least one cicada during southeastern summers.

More Information

For more information about cicadas, visit the Alabama Extension website, www.aces.edu.

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