The multitudinous mischief of Magicicada.
I can’t say that i’ve ever taken a bite of German chocolate cake and thought, “Not bad, but what this could really use is a cup of blanched cicadas.”
Yet you might have noticed that cicada recipes were a minor rage on the Internetosphere this spring, along with cicada recordings, YouTube videos, SoundCloud audio recordings, interactive tracking maps, and (of course) a Twitter hashtag—#swarmageddon. All of it was part of a wave of excitement, enthusiasm, interest, apprehension and dread in anticipation of the Great Brood II Emergence of 2013; after a 17-year sojourn spent underground, millions upon billions of periodical cicadas were set to make their way to the surface along a swath of East Coast states from North Carolina to Connecticut, then clamber into the trees and let loose with a hellacious racket, all in the name of love.
Except it didn’t unfold exactly as expected. Maybe it was the slow and fitful spring that kept soil temperatures lower than usual well into late May. Maybe it was development that has paved over vast acres in the nearly two decades since the last Brood II emergence. Or maybe it was that all the hype had everyone imagining an army of red-eyed bugs marching shoulder to shoulder across the land. At any rate, if you were in a cicada hot-spot, you knew it, and then some; but only a mile away, you might find yourself with nary a chirper to be found, wondering what all the fuss was about.
In the places where cicadas emerged, however, they lived up to the advance press. The sound overwhelmed: a high-pitched, unearthly whir overlaid with a throbbing, pulsing ratcheting. Trees at cicada ground zero seethed with a restless, fluttering dance of winged insects.
There are estimated to be thousands of cicada species worldwide; in Virginia, we are familiar, of course, with “dog day” cicadas, the soundtrack of summer, that appear every year sometime around the end of June. But in all the world, it is only in the eastern half of the U.S. that periodical cicadas of the genus Magicicada are found. There are seven species in all, four of which reappear on 13-year cycles, and three of which, including the members of 2013’s Brood II, live a 17-year cycle, making Magicicada the longest-lived insect in all of North America.
What is much more of a mystery, however, is how, after nearly two decades living underground, where they spend their long nymphal years feeding on tree roots, they all know when it’s time to come out. The immediate cue is a consistent soil temperature of 64 F at about eight inches depth. But for 16 springs the 17-year cicadas ignore that cue and then, in the 17th spring, for some reason, they don’t.
Small holes dotting the ground around trees are among the first signs of the emergence; the nymphs build tunnels to the surface, and then emerge—often many, many at once—in the night and almost immediately thereafter molt (the process is called “ecdysis”) to take their adult form. Where cicadas have emerged, you’ll find the brown husks of their shed nymphal skins clinging to leaves and tree trunks and scattered upon the ground. (If you look at the size of the adult and the size of the nymphal skins, it’s hard to imagine how the former fit inside the latter.)
For the first few days after the molt, the cicadas are a pale whitish-pinkish-orange (though with those distinctive red eyes); it is during this “teneral” stage that apparently they make the best eating. Just in time for this year’s emergence, the United Nations issued a report urging people the world over to eat more bugs (a practice known as “entomophagy”): “Insects are healthy, nutritious alternatives to mainstream staples such as chicken, pork, beef and even fish.” In this spirit, the New Haven Register reported that a local sushi chef in Connecticut planned to put cicadas on the menu, and National Geographic pointed out that not only are cicadas low-carb and healthy but also—making them the perfect snack of the era—gluten-free.
The emerging cicadas make for quite a culinary bonanza, of course, for other species as well. Cicadas have no particular defense mechanisms, nor are they the gifted aerobats of the insect world, with a lumbering, underpowered flight that is singularly unimpressive to behold. The huge numbers of cicadas, however, assure that many will successfully run the food-chain gauntlet to clamber their way into the treetops, where the males begin their singing (although only during daylight hours) to attract their mates. They make the sound with a pair of ribbed membranes, called tymbals, on their abdomens. And a deafening ruckus it is; as the website Magicicada.org notes, at close range, a mass of singing cicadas can hit a noise level in the range of 90+ decibels.
But then, just when the human residents are driven to the brink of madness, it’s all over. Within a few weeks of the emergence, the females lay their eggs, and the nymphs begin hatching and dropping to the ground below to burrow deep into the soil where they will remain, sucking nourishment from the roots and slowly growing, for years to come. And then the adults all drop dead.
Which means, yes, a trillion cicada corpses littering lawns and smelling something like ripe Limburger cheese, just about in time for 4th of July picnics.
But good news! Brood X, which is even bigger, is set to return in 2021.