Billions, Yes Billions, Of 17-Year Cicadas Will Emerge In 2021

ACROSS AMERICA — If your goal in 2021 is to be loud about what you want, you’ll have some competition from a horde of occasional visitors to several Mid-Atlantic and Midwest states.

Prepare to say hello to a whole lot of Brood X, or Great Eastern Brood, cicadas. They only emerge from the ground in large numbers every 17 years, and they make a big impression when they do.

If you thought the annual cicadas that serenade you on summer nights were loud and prolific, that’s nothing compared to what’s coming up this May, give or take a few weeks.


Count on billions of these periodical cicadas tuning up in the areas where Brood X has been detected. There are two species of periodical cicadas — the 17-year cicadas, found in northern states, and the 13-year cicadas, found in the South.

This is either wonderful or terrible.


It’s wonderful because the synchronized emergence of Magicicada cassinii, as this cicada brood is scientifically known, is a true marvel of nature. The species’ extraordinarily long life cycle — the longest of any insect on the planet — is part of an evolutionary strategy that has allowed the cicada to survive for 1.8 million years, or from the Pleistocene Epoch, according to a CBS News report.

It’s terrible because when these cicadas all tune up at once — which they’re wont to do because the survival of the species depends on hooking up — you may want to be anywhere but where you are, especially if we’re all still isolating because of the coronavirus.

If just thinking about what’s to come makes your ears ring, it may be a good time to book a trip to somewhere west of the Mississippi River.


They are that loud.

How loud?

The collective song of male cicadas calling for mates can reach up to 100 decibels. Think of a Harley-Davidson motorcycle with straight pipes constantly running outside your window.

The male cicadas are the ones that make all the noise.

They do it by vibrating their tymbals.

What are tymbals? As described on the Chicago Botanic Garden website, tymbals “are two rigid, drum-like membranes on the undersides of their abdomens.”

Newly adult cicadas are in a rush to mate because they don’t live very long after that — three, maybe four, weeks. The females don’t have tymbals and can’t produce the same sounds. They wait quietly to do their job in perpetuating the species, which is to lay as many eggs as possible, up to 600, before they die.

After mating, the females split the bark on living tree trunks, branches and twigs, burrow in and lay between 24 and 48 eggs at a time. Rinse and repeat.

Of course, scientifically, it’s significantly more complicated than that.

If you’re on the terrible-not-wonderful side of the 17-year cicada emergence equation, think of it this way: You’ll get to bear witness to what is still an unfolding scientific mystery. Scientists can’t entirely explain the synchronized emergence of periodical cicadas, but one evolutionary hypothesis is that the forced developmental delay was an adaptation to climate cooling during the ice ages.

This is a scientific rabbit hole, so perhaps it’s best just to see it as a sign of rebirth for 2021 after a year no human on the planet wants to see repeated.