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In the Brood for Love: After 17 Years Cicadas Ready to Descend on the Northeast, USU Entomologists Say

 

A parody of old movie posters - a large cicada descends on two terrified people. The text says "RETURN OF THE BUGS: BROOD X IS BACK"

By Ian Neligh


The swarm will arrive any day now. 

Billions, possibly trillions, of cicadas with bright red eyes will feverishly tunnel up from the ground where they’ve waited the past 17 years. 

One to two inches in size, the insects will take advantage of the warming spring temperatures to dig their way free and swarm up into the nearby trees. Soon Brood X will invade the Washington D.C. metro area, and fourteen other states to reproduce for about six weeks before disappearing again for another 17 years.

To the uninitiated, the flying, five-eyed periodical cicada with its frenzied, 96-decibel mating song might sound like something from an ambitious B movie. But entomologists with the Uniformed Services University of the Health Sciences (USU) stress this is a harmless and unique chance to encounter the rare cicada event and, for the brave, maybe even a unique culinary opportunity.

Dr. James English, USU adjunct assistant professor of Preventive Medicine and Biostatistics now at the U.S. Geological Survey, recommends the best way to experience this phenomenon is to wait until midnight, get a flashlight and head to a forest as the insects emerge from the ground.

“Go out there with a headlamp or flashlight and watch them come out of the ground,” English said. “Silently and slowly they come out of these holes in the ground, climbing up a tree or a bush or a vine.”

After ascending, the cicadas will then break out of their nymph exoskeleton and over the next five to six hours harden a new adult life stage with wings.

A cicada emerges from its shell; cicadas sit on a tree
Once the cicada nymph emerges (left), it climbs to a safe place to shed its exoskeleton and sits for a bit until it enlarges as the adult cicada (right). (Photo
credit: Gene Kritsky, Mount St. Joseph University) 

“(They’ll) have translucent orange wings and orange legs and the beautiful cherry red eyes,” he said. 

The colorful insects will then spend the next six weeks trying to reproduce, laying eggs in the trees before dying, and the process begins all over again.

There are currently 15 documented cicada broods which come out either every 13 or 17 years. Brood X, named after the Roman numeral 10 and its order of classification, is one of the largest of these groups. The last time they debuted Facebook was still a new website and the television show “Friends” had recently ended. 

Some of the oldest living insects on the planet, cicadas are mentioned in Homer’s “The Iliad” and observed by settlers in North America as early as the 1700s.

According to English, the reason the cicadas have such a long underground development period, where they spend their time feeding off the roots of trees, is because of the need to outlast their predators — which is basically everything. Squirrels, rabbits, birds, and mice will all enthusiastically eat cicadas when they emerge. It’s essentially an all-you-can-eat cicada buffet, and all those extra calories go to increasing the predator population. 

English said the number 17 has meaning. The prime number keeps the different cicada broods from coming out at the same time, except for every 221 years when hypothetical 13-year and 17-year broods might be co-located and emerge simultaneously, allowing them to breed with each other. 

One of the tricky aspects of studying cicadas is in learning how they keep time. How is it they know 13 or 17 years have passed when they spend it under the ground? The prevailing thought is they have some sort of molecular clock which keeps track of the warming ground temperatures or, as English theorizes, through the hormones produced by trees as they bud in the spring.

A group of cicadas on some leaves
Billions of Brood X cicadas will be emerging throughout the eastern U.S. soon for a mating ritual that only happens every 17 years. (Photo credit: Gene
Kritsky, Mount St. Joseph University)

Navy Lt. Cmdr. James Dunford, a medical entomologist, and USU adjunct professor, said he experienced Brood XIII in eastern Wisconsin while growing up.

“I think you’ll find, in general, some people will be freaked out, the people who have an aversion to bugs and certainly to lots of bugs piled up on each other,” Dunford said. “But for me, just like monarch migrations and some of these other amazing entomological phenomena, this is really one of the top 10 to me — maybe even top five of things you can see in the world of entomology.”

Dunford said, despite their ability to make some people feel squeamish, the cicadas are completely harmless.

“There have been some traffic incidents associated with lots of cicadas,” Dunford said. “Maybe the conditions are slick, or they’re flying into windshields.” 

As far as experiencing the cicada invasion, Dunford said it depends on how comfortable someone was with insects.

“You can get as close as handling them, because these are easier to handle than the annual cicadas, … or monitor them from a distance with binoculars or even actively participate (in studies) and submit pictures to universities,” Dunford said. One such study “Cicada Safari”, sponsored by Mount St. Joseph University in Cincinnati, can be found in online App stores.

A cicada on a leaf
Photo credit: John Cooley/cicadas.uconn.edu

For the adventurous, there are also culinary experiences to be had with the large Brood X emergence. The insect is apparently edible and the curious can find recipes in cookbooks such as “The Cicada Cookbook” or “Cooking with Cicadas.”

English said he has eaten the insects during fundraisers prepared by chefs.

“And it’s not good. It’s never good,” English said. “It is mainly because the chefs don’t know what they’re doing with bugs. They will cook with adults after their shells have hardened, so you’re eating mainly crunchy shells. And males are hollow, so they are almost exclusively shells. Females will at least be filled with eggs.”

English said his advice to chefs is to contact an entomologist and collaborate, adding the best time to eat them is after they’ve first broken out of their shells.

“That is when they’re delicious,” English said. “If you were to take shrimp and avocado and mix them together with just a little bit of butter...that’s the closest thing (to their taste) I can think of.”

Whether people are looking to avoid, observe, or even dine on Brood X — one thing is for sure — there will soon be plenty of opportunity.