What's That Noise??

Dana Owen
May 23
4 min read

Updated: May 27

Why We Should Celebrate Periodical Cicadas

Source: Atlas Obscura, "The Cicada Poems of Ancient Greece"

Having been surrounded by an increasingly loud hum these last few weeks in Old Fort, we've had many customers ask us "What's that noise?!". No, it's not an alarm--just thousands of cicadas in the trees! Their populations are scattered around the area, so you may not have them in your community - plus, they haven't been here for almost two decades, so it's understandable if you don't remember the sound!

The Periodical Cicada (Scientific name is literally Magicicada)

Cicadas are an amazing and bizarre insect regardless of how long they live--most annual cicadas emerge every 1-5 years, and we hear them singing in the trees mid to late summer. Most of what we are hearing now is the Brood XIV periodical cicada, which sound a bit different and emerge earlier in the season. One of the longest lived insects, they've been underground for SEVENTEEN YEARS, and then emerge for only a few weeks of life above ground!

This brood hatched 17 years ago, then dug 5-6 feet underground as tiny nymphs. They then spent almost two decades slowly growing while feeding on root sap (and doing other magical unknown things) before they dug back to the surface. After a brief period of slowly bumbling around in their final nymph stage, they undergo their last metamorphosis--literally splitting down the back and shoving out of the old shell to finish growing their wings. Now is when we really start noticing them, as they spend weeks flying around like klutzy whirligigs screaming for mates!

Maybe they gross you out? Or you find the hum just a bit too loud for comfort? Or you're worried about your gardens being eaten?

Freshly hatched in Old Fort, Credit: Chris Whaley

Here's why Brood XIV is a good thing for WNC:

SO MUCH FOOD!
Adults provide an incredible amount of food for birds, amphibians, reptiles, small mammals, and fish - which then has a ripple effect of boosting the entire ecosystem. This is perfect timing following the loss of wildlife and habitat from Helene! (And if the world descends into further chaos, we may just want to chow down too - they're highly nutritious and considered a delicacy by many cultures.)
IMPROVED SOIL STRUCTURE
Nymphs burrowing up through the soil provide improved aeration and more effective water infiltration, which both helps plants survive during periods of drought and helps mitigate heavy rains as the soil can absorb more water and we have reduced runoff and potential for flooding.

INCREASED SOIL FERTILITY
The molts as well as any adults not eaten by predators are seemingly everywhere - and they will all be decomposing... that's a lot of natural fertilizer! This will also support plant health along with the improved aeration and water flow.

ENVIRONMENTAL INDICATORS

Because of their long and very unique lifespans, periodical cicadas are very important study subjects. Changes in their populations, health and distribution can help inform studies on the effects of human development, habitat fragmentation, pollution, and climate change.

Cicadas symbolize rebirth, renewal and transformation in many cultures and have been featured in poems, music, and art around the world for centuries. WNC could use such a symbol as we rebuild and recover! Read on for FAQs and fun facts!

The Last Nymph Stage The Last Molt Final Winged Stage

Will they ruin my gardens?

Short answer--no, but taking extra care with shrubs and trees is helpful.

Adult cicadas barely eat (they have something else on their minds), so no fear of your annuals and perennials being damaged. Females do cause some damage when depositing eggs - they use their ovipositor to saw into branches and then insert their eggs. This can cause leaf drop and die off of branch tips (known as 'flagging'). While it's unusual for this to cause long term damage or kill the plant, it can be helpful to cover younger shrubs and trees with a fine mesh to prevent females from accessing them. Regardless of whether you protect with mesh, we recommend taking extra care with deciduous shrubs and trees planted within the last few years (cicadas don't lay eggs in evergreens). If properly watered and mulched, your plants will be better equipped to handle any extra stress (note that while using some compost or a root booster such as triple superphosphate when planting a new shrub or tree is often helpful, you should not fertilize them when struggling with pest or disease damage--this can lead to them putting more energy into new growth and therefore having less to defend themselves).

Why are there so many?

Cicadas have evolved to survive by simply overwhelming predators by sheer numbers. They have little to no defenses, so their massive populations ensure that enough survive to breed and have young. During their peak, in highly concentrated areas, there can be up to 1.5 MILLION cicadas per acre!

Tell me more about the sound.

The males compete with one another to see who can make the loudest mating call by flexing their tiny cicada muscles to rapidly buckle membranes called 'tymbals' against their body. This creates a speedy clicking noise, which sounds amazingly different when thousands of cicadas are 'singing' at once. The males will often engage in synchronous chorusing - which makes them sound even louder and is hypothetically used to both grab the attention of females as well as confuse predators. Brood XIV is known to be the loudest of our cicadas, with noise levels reaching 100 decibels (comparable to a passing jet)!

Those red eyes are creepy.

Actually, they have 5 eyes! Three are on their forehead. So you can be extra creeped out!

For more about periodical cicadas check out this excellent article from the Irvine Nature Center in Maryland. We hope we helped you see these fascinating insects in a new light!