2.5-minute read

In about six to eight weeks, billions (or possibly trillions!) of periodical cicadas will emerge from the earth at the same time in the Eastern, Great Lakes, and Mid-Atlantic regions of the U.S. Some things have been bugging us about this mass insect invasion. Why do cicadas only pop up-top every 13 and 17 years? What do they do underground for all of that time? And why are there so many of them? We thought we’d do a little digging and find out, so here’s a quick Q & A about the noisy critters to keep you up-to-date on your insect info—you know, for Trivial Pursuit.

What is this ginormous bunch of bugs called?
The astonishingly large populations of cicadas that emerge from the earth at precisely timed 13 and 17-year intervals are called broods. In 1893, the broods were assigned Roman numeral designations by American entomologist Charles Marlatt. The 2021 17-year Brood X is made up of three different species with distinctive color patterns, sizes, and behaviors. Every 221 years, the 13 year and 17-year broods come out together in one tremendous bug fest. The next time that will happen is 2118. Optimists: schedule your 97-year cicada reminder with Siri now.

Why the extended percolation time?
About two feet below the earth, baby cicadas, known as nymphs, begin the long preparation for their emergence by feeding on fluid from tree and plant roots until they have matured enough to dig tunnels and crawl to the surface. The brood making their debut this year began their journey way back in 2004.

How do cicadas know when to launch?
Some biologists believe that fluctuations in root fluids might serve as cues for marking the passing years, and that cicadas may have a built-in timing mechanism that prompts them to start tunneling upward. Soil and bug body temperatures reaching a specific level could trigger the synchronized “let’s do this” launch.

What’s all the noise about?
For the first two weeks of their short, four to six-week lives, male cicadas gather in a colossal insect chorus to serenade the lady bugs. By contracting their rib membranes, the singing insects create surreal-sounding cycles of raucous buzzing that can reach 100 decibels—equivalent to the noise level of a jackhammer or a jet flyover at 1,000 feet.

Why are there so many of the little buggers?
There is safety in numbers. Cicadas are a non-toxic source of food for all manner of creatures including birds, squirrels, cats, dogs, turtles, snakes, and spiders. But even the hungriest of the hungry can only eat so many of the crunchy insects from a billion-bug buffet. Emerging synchronously in enormous numbers helps to ensure that enough cicadas will survive to sustain their brood and come back to sing another year.

When do cicadas go underground?
Female cicadas lay anywhere from 2-30 eggs in tiny nests on pencil-sized twigs. In about six to ten weeks the eggs hatch, the nymphs fall to the ground and burrow into the soil and the amazing prime-numbered life cycle of the periodical cicada begins again. Pro-tip for Brood X states—hats on when roaming under tree canopies this July and August.

Is 2021 Brood X emerging at a location near me?
The American Forest Service has created a handy map indicating where and when the 13 and 17-year broods emerge. You can check it out here.

Are there any songs about cicadas?
As a matter of fact, there are quite a few! These are some top picks:
• The Squirrel Crossed the Road/Jane Siberry
• Day of the Locusts/Bob Dylan
• Sicka Cicadas/Kathy Ashworth

So that’s this bug’s life—thirteen to seventeen years under the ground and only about six weeks under the sun. Perhaps the cicadas are not singing, but complaining—and who could blame them. Whether your response to the synchronized mass emergence of cicadas is “oh, wow” or “oh, eww”, we think you’ll agree that the recurring natural phenomenon is pretty remarkable.

And that’s this week’s Wild & Wondrous. Don’t forget to spring forward. Welcome back, light! Btw, today, 3.14, is also Pi (Π) Day, so if you are into numbers or into pie or into both, go wild!