By Mary Hightower
U of Arkansas System Division of Agriculture

Entomologists say two broods of periodic cicadas will be making a rare simultaneous emergence this spring. The last time this happened in the U.S. was in 1803 and the next one won’t happen for another 221 years.  

Arkansas is home to brood XIX, a group whose adult insects emerge every 13 years. The brood’s last emergence was 2011 and the next will be 2037. Brood XIII, which emerges every 17 years, last emerged in 2007 and will again emerge in 2041. Brood XIX is the largest 13-year brood in the United States, covering 15 states.

Cicadas spend most of their lives underground as nymphs, then “they all emerge at once, in an effort to overwhelm their natural predators by sheer numbers,” said Jon Zawislak, extension assistant professor-apiculture and urban entomology. “Anything that might want to eat a cicada will be able to get a belly full, so the rest can survive to continue the species.”

The insects know how to turn up the volume, often hitting 90-100 decibels, louder than a hair drier.

“I remember camping near the Buffalo River in the early summer of 1998, and it was LOUD,” he said. “Also, you couldn’t catch a fish to save your life. They were all so full of cicadas they couldn’t be tempted by anything else.”

Brood XIII is found in Illinois, Indiana, Iowa, Michigan and Wisconsin. Brood XIX can be found in Alabama, Arkansas, Georgia, Iowa, Illinois, Indiana, Kentucky, Louisiana, Maryland, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee and Virginia.

“We will see and hear a lot of the Brood XIX in Arkansas. Brood XIII will mostly be in northern states,” he said. “If you really want to be at ground zero for all the cicada action, you might trek to Springfield, Illinois, where there will be a lot of overlap.”

Zawislak said the two broods won’t be alone.

“There are a number of annual cicadas that will come out and there are often some stragglers from other broods that don’t quite synchronize with the rest of their group,” he said. “Arkansas is home to 20 different species of cicada.”

The brood that will emerge in Arkansas is of a species called Magicicada tredecassini, which emerges this April-May-June.

“But you will see and hear other cicada species every year, that come out later, ranging from April to November, especially members of the genera Neotibicen and Megatibicen. Factors like temperature and rainfall will affect how soon they emerge and how long they stay around,” Zawislak said.

What is that noise?

The cicadas’ unique sounds are part of their mating process. In their “choruses,” adult males “sing” by vibrating a membrane on the sides of their bodies called a tymbal. Females can make clicking noises to indicate they are ready to mate. 

The song of the African cicada, Brevisana brevis, can hit 107 decibels from 20 inches away. That compares to a chainsaw, which can hit 110 decibels from the same distance, according to the University of Nebraska at Lincoln.

John Lovett, science editor for the Arkansas Agricultural Experiment Station, had to improvise a solution when the din grew too loud during a camping stop near the Cumberland Gap.

“I had to stuff napkins in my ears to sleep and that didn’t even really work well,” he said. “A Dutchman in yellow wooden clogs came by my camp the next morning to talk about the cicadas over coffee. I think he was as impressed by the cicadas as I was his shoes.”

Lifecycle

After mating, the females lay eggs on tree branches and the adults die soon after. 

“They are only around making noise for about four to six weeks,” Zawislak said. “After a few weeks the nymphs emerge from the eggs and drop to the ground, where they dig down and feed on the sap from tree roots for years.”

The nymphs may feed on roots of smaller plants first, then switch to tree roots when they are older. 

“After their allotted time, they crawl out and up onto something vertical like a plant stem, tree trunk, or a house, fence post or mailbox and molt one last time, emerging as winged adults,” Zawislak said. “Most people have probably seen the hollow shed exoskeletons around in late spring or early summer.

“They are neat creatures. And large,” he said. “Most sap-feeding insects don’t get that large, which is why they take so long to grow. But when they appear all at once, they become a feast for small predators. Which gives those animals a population boost.  Which gives larger apex predators a population boost. These big bugs are an important link in the food chain, between trees — feeding on sunlight — and big, majestic wildlife.”

They might also become a feast for pets, but owners shouldn’t worry.

“I do not know of any poisonous or toxic effect that cicadas may have on pets that happen to eat one or more,” said Jeremy Powell professor of animal science and veterinarian for the Division of Agriculture. “However, they do have that very heavy exoskeleton that could be hard for pets to digest and may lead to some minor intestinal upset. That scenario would likely be short-lived.”

Mistaken identity

Zawislak said the cicadas are sometimes called locusts.

“Early European colonists who had never encountered them before likened the sudden appearance of giant insects to a biblical plague, even though they did not eat crops like a hungry hoard of grasshoppers,” he said. “Once the adults emerge, it’s back to singing and making more cicadas. So, it’s one generation every 13 years for this brood.”

The CDC notes that it is not claiming that exposure to cicada sounds is harmful.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on X and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on X at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on X at @AgInArk.

About the Division of Agriculture

The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.

The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on five system campuses.

The University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.