The duel emergence of Brood XIX and Brood XIII periodical cicadas means an influx of cicadas this spring — here’s why this is so remarkable.
Words and photography by Mike Dunn

In spring of 2011, I noticed dime-sized holes in the ground one morning when I walked out to my car. Several days later, I started seeing the sheds — cast-off “skins” of creatures that had spent the last 13 years underground — on vertical surfaces like tree trunks, porch posts and even my car tires. The invaders were coming to the surface in droves. The noise was earsplitting, and they dominated the scene for weeks. 

These creatures were members of Brood XIX of periodical cicadas. And this year, they’re baaaaack!

Cicadas abound every summer in North Carolina. We have several species of so-called annual cicadas, some of which emerge late in summer after spending only a few years underground. They are much less abundant, on the large side and green in color. 

By contrast, periodical cicadas emerge in spring, and they have black bodies and bright red eyes. Periodical cicadas are best known for being synchronized on either a 17-year or 13-year cycle. There are seven species of periodical cicadas (three with 17-year cycles and four with 13-year cycles) in the genus Magicicada, all of which are only found in the Midwest and Eastern United States. Groups of cicadas that share the same emergence years over a certain geographic area are called broods, and broods can include more than one species. 

The special thing about this spring is that there will be a dual emergence of Brood XIX (13-year cicadas) over much of the Southeast and Brood XIII (17-year cicadas) over parts of Illinois. The last time this happened was in 1803, and the next time will be in another 221 years! Scientists estimate there will be trillions (yes, with a “t”) of periodical cicadas emerging throughout the range of these two broods this April and May. 

Brood XIX is thought to be the largest brood of 13-year cicadas. They will emerge this year in scattered locations in North Carolina from Raleigh to Asheville. Each of these cicadas started as a nymph that dropped from a tree and burrowed up to 2 feet into the soil 13 years ago. They started out at about 1/16 of an inch in length and resembled termites or cream-colored ants. But for more than a decade, they have been quietly feeding on the sap from tree roots. They molted several times in their underground chamber, apparently keeping track of time by some as-yet unknown mechanism; researchers believe it may be tied to the seasonal cycles of the trees. 

Now, in the spring of their 13th year, these full-grown nymphs will dig a tunnel to the surface, sometimes including a mud turret above ground (especially if the soils are moist) and wait until conditions are just right. Studies show that they emerge from the soil and look for a place to transform when soil temperatures at a depth of several inches reach 65 degrees Fahrenheit. They typically emerge at night.

If they are in your area, you should have several nights to go out and look for the nymphs crawling up vegetation and other vertical surfaces. They soon settle down and start the transformation into an adult. First, their back split opens and a ghost-like, white adult with wrinkled wings pulls out in a slow, arching motion. It then hangs onto its nymphal skin and pumps fluids into its wings, slowly expanding them. Over the next hour, the body darkens from white to black. 

Males usually emerge first, and when a sizable number are above ground, they begin singing, which is known as chorusing. Our cicadas have a pulsating song, sounding like the phrase pharaoh, pharaoh, repeated incessantly — or a distant group of alien spacecraft (or maybe I watched too many sci-fi movies as a kid?).

Males use specialized drum-like structures on their abdomen, called tymbals, to make their astonishingly loud sounds. As tiny muscles vibrate the tymbals, the buzz can reach over 90 decibels, rivaling the noise made by a lawnmower or motorcycle. 

Females respond to these choruses. After mating, they use a knife-like egg-laying device, called an ovipositor, to make slits in tree twigs to deposit their eggs. These slits may cause the distal portion of that twig to die (known as flagging). Though it may damage young trees, it is no more than a pruning on mature trees and causes no permanent damage. Eggs begin hatching in about six weeks. The tiny nymphs will drop to the ground, burrow into the soil and start the cycle anew. The singing typically lasts four to six weeks and then the adults begin to die.

The long life cycle of periodical cicadas may have evolved to make it more difficult for potential predators to synchronize with them — these cicadas are, after all, on the menu of almost everything from snakes to birds to bears.

With their huge numbers at emergence, some will survive to mate and reproduce. Interestingly, there is a fungus that is synchronized with the emergence. The fungus is in the soil in a resting phase until the cicadas emerge and pick it up on their bodies. Infected adults have a whitish abdomen that eventually breaks open, releasing more spores into the soil for the next generation.

There are several things I hope to witness for the first time in this year’s emergence: finding some adults infected by that fungus; encountering a rare white- or blue-eyed adult (a genetic variant); and seeing and photographing the tiny nymphs after they hatch. Perhaps (stress that word perhaps) this year I’ll taste one of these “ground shrimp” as it emerges. Historical records indicate that many Native American Indian and early European settlers feasted upon the emerging nymphs, and some people still do. I may work up the courage to try them this year, as I’ve heard the taste compared to popcorn, bacon or crab, depending on the cooking method.

If you see them, don’t be afraid; cicadas can’t hurt you. They don’t bite or sting. But I have read that certain power equipment, like chainsaws, may mimic the sounds enough that it can attract a swarm of adults (could be interesting if you’re doing yardwork!). If you have delicate young trees, you may want to protect them with mesh netting. 

Otherwise, these cicadas are actually quite beneficial to the environment: The tunnels of the nymphs help aerate the soil; the egg-laying provides natural pruning of tree branches; they are a bountiful food item for a host of natural neighbors; and the decomposing bodies of millions of adults adds essential nutrients back into the soil. I hope you can enjoy this incredible natural event! 

This article originally appeared in the May 2024 issue of WALTER magazine.