This year has been quite eventful already, and it’s about to get even more interesting with the anticipated emergence of certain periodical cicadas! Two different groups of cicadas are set to emerge this year: the 13-year and 17-year cicadas. It’s a rare event because these prime number cycles seldom overlap. In fact, it’s been over 200 years since both emerged simultaneously!
Residents in Western North Carolina will mainly witness Brood XIX, while the other group, Brood XIII, will mostly emerge in Illinois. We’re talking about millions of these periodical cicadas emerging!

Dr. Matt Bertone, the Director of NC State’s Plant Disease and Insects clinic and an entomologist, has shared some insightful information in an article. Here are some highlights:

When Will They Emerge?
Around May in North Carolina, when the ground temperature reaches a certain level, the nymphs, which have been living underground and feeding on tree roots, will emerge as adults. That’s when the noisy mating ritual begins. After a few weeks, the adults will die out and the young will hatch from the branches and drop to the ground below. There they burrow next to a root, and tap in for the long haul, feeding on the juices of the plant for thirteen years.

Don’t We Have Cicadas Every Year?
Yes, we do, but those are different from the periodical cicadas mentioned earlier. The annual or dogday cicadas emerge each year, typically in June or July, and produce that infamous summer sound.

Why Are They So Loud?
Male cicadas make loud calls using a special organ called a tymbal. These calls are specific to each species and attract females of the same species. When millions of them are singing together, it creates a deafening chorus.

Will They Damage Plants?
While adults and nymphs feed on plants, and females saw into twigs, they rarely do major damage. In areas with a lot of activity, after the dust has settled, you will often notice trees and other plants with “flagging” symptoms. This is where individual branches or twigs break from being weakened by the egg laying, causing the apical section to break or die off. Unsightly as it is, this can be thought of as merely a “pruning” event.

flagging of branches in a plant damaged by periodical cicadas

However, since they will feed on, and lay eggs in various woody plants, a few commodities might be affected by massive amounts of these insects. We’ve seen blueberry growers have significant damage in previous years and other woody crops (such as fruit trees — apples, peaches, and pears — as well as grapes) be negatively affected. Thankfully, these cicadas are only out for a few weeks.

Should We Be Concerned About Their Emergence?
Periodical cicadas are a unique phenomenon found only in the eastern United States. They are harmless to humans and pets, though they may be a nuisance. Their emergence provides ecological benefits, serving as a food source for many animals. So, if you spot them, consider yourself fortunate to witness this remarkable natural event!

As we await the emergence of the 13-year and 17-year cicadas, it’s a reminder of the rare, natural show ahead. Dr. Matt Bertone’s nuggets of wisdom help us understand what’s coming and their unique life cycle that follows. Sure, their noisy choir and brief interruption might be inconvenient, but it’s important to remember the special job these insects have in our ecosystem. So, as Brood XIX gears up to make its appearance in Western NC, let us all observe and appreciate this phenomenon in nature’s playbook!