A deconstruction of Periodical Cicadas

I warned you they were coming here. I showed you proof of the invasion of the red-eyed monsters (aka, periodical cicadas) here. And I showed them to you at the height of their emergence in my yard here. Today, a month after their initial emergence in my yard, I am happy to report that the prolonged mating frenzy of the periodical cicadas is winding down.

The most obvious signs of their decline are the body parts scattered across the yard — a single wing here, a severed head there. Every morning for the last three days, I’ve been sweeping dead cicadas from my back deck, which is shaded by a mighty Northern Red Oak. Yesterday’s body count was ten; this morning’s was seven. Accompanying the cicada corpses are proof that the females’ egg-laying is done — small severed oak branches litter the deck and ground. I’ve read that female periodical cicadas are especially fond of young oak twigs, and my backyard evidence confirms this.

I’m not worried about damage to this oak. It’s about 100 years old and 85 feet tall with a trunk diameter too big for two adults to embrace and touch hands. It can accommodate a little pruning by the female cicadas.

However, I am steamed about what they did to one of my prize young deciduous magnolias. Magnolia sprengeri ‘Diva’ is not a native species, but the description of its stunning early pink flowers was enough to persuade me to buy one about eight or nine years ago. For economic reasons, I buy very small, bare-rooted plants, and my Diva did not respond enthusiastically to transplanting, nor did it like being enclosed by a wire cage — a necessity to prevent deer predation.

However, Diva began to come into her own after her area was enclosed by deer fencing and we could remove the cage. She didn’t bloom this year, but I had high hopes for next spring — until the cicadas destroyed those hopes. For reasons known only to a fertile female in egg-laying frenzy, one of the periodical cicadas chose to deposit her eggs three feet down from the top of Diva’s leader branch.

A leader, for those who may not know, is the central branch of a tree — the one that shoots up straight and tall and from which lateral branches sprout. A strong central leader branch helps create a tall, straight, healthy tree. Diva had a nice leader branch before the cicadas killed it. A few days ago, I noticed it dangling from the top (about 9 feet up) by a shred of bark. Wonder Spouse cut it off cleanly for me (he’s taller than me), and I photographed the carnage before removing it. Three feet of the top of Diva’s leader branch, dead:

Diva’s severed “head”

The cicadas also killed several lateral branches of my gorgeous Ashe Magnolia, but — knock wood — it seems to be mostly intact. I’m hoping that the diminishing high-pitched thrum of the periodical cicadas and the increasing number of ant-covered cicada bodies strewn across the yard mean that Diva’s fate will not be shared by other beloved woody specimens. Another couple of weeks should tell the tale.

They won’t be back until 2024, which suits me fine. By then, my woody specimens should all be large enough to withstand damage from the female periodical cicada’s ovipositor. By then, Wonder Spouse and I will be well into our senior years; perhaps the perspective of increasing age will mellow our annoyance with the mating enthusiasm of these red-eyed monsters.

I read in my local paper yesterday that it’s time for another emergence of the 13-year periodical cicada common to my region — North and South Carolina. The last emergence of this species was 1998. I remember it well. I thought extra-terrestrials had landed their spaceships just out of sight and did not turn off their engines. I had never before heard such a high, loud, continuous hum.

I could hear it in the house with the windows shut tight. To my ears, the sound was almost as bad as if someone were perpetually scratching fingernails on an ancient slate blackboard. Periodical cicada calls are not remotely similar to the lazy thrumming of our annual cicadas — their song just vibrates humid late-summer air, lulling sticky bodies into uneasy slumber. The periodical cicada calls are different; they penetrate your brain and jangle your nerves. And then the bugs appear — everywhere.

I had never seen so many of one kind of insect at one time in my life. They covered every bush, the steps of my house, the fence. My young lab mix was delighted, dancing and leaping as she snapped up as many of the slow-moving cicadas as she could. Fortunately, the cicadas aren’t poisonous, but the vet still encouraged us to lock the dog inside the house until the cicadas dispersed a bit more into the environment.

If you live in a suburb without much forest cover — or a city — you probably won’t hear these short-lived sonic disrupters. If you live in North or South Carolina, I encourage you to take a trip to the countryside in late April/ early May, when the cicadas are predicted to emerge. You will never hear anything like the sound of gazillions of these red-eyed insects humming their love calls.

But if you live in or near forests that have remained undisturbed for the past 13 years, prepare yourself. Gardeners may want to take preventive measures to protect any young trees or shrubs with relatively small stems. Adult females lay their eggs in these thin branches. The larvae soon emerge, drop to the ground, and dig in for another 13-year development cycle. In my yard thirteen years ago, a young dogwood didn’t survive the massive egg-hole drilling that the periodic cicadas subjected it to. Branches broke and dropped, leaving a sad, injured tree that I eventually removed.

This time around, I’ve got many more shrubs and young trees with branches likely to be deemed ideal by the female cicadas. When I hear the high-pitched hum begin, I’ll be covering many of these smaller woody plants with a spun garden fabric that will deny access to these insects. The good news is that the entire life cycle only takes four to six weeks.

This late spring, my landscape will likely be haunted by high hums and white-fabric-covered shrubs. At least I know the haunting will be temporary, and won’t return for another thirteen years.