For the past 17 years, these insects have lived as nymphs deep beneath the soil, drinking sap from tree roots. For the past week, they have been emerging in much of the eastern South — Georgia, East Tennessee, North Carolina, Virginia — and they will arrive soon in the Mid-Atlantic and Midwest. Look for them when the soil eight inches deep reaches a temperature of 64 degrees. (If you’re in Brood X’s range, you can be part of a citizen-science project that tracks their emergence.)
After a year of weather calamities and pandemic shutdowns, people are already muttering about the apocalypse, but this, mercifully, is a natural occurrence, not a biblical plague. Cicadas are not locusts. They don’t even belong to the same order of insects as locusts. Cicadas don’t strip fields of every grain of rice or wheat, as swarming locusts do. Cicadas don’t sting, and they don’t bite. The strawlike appendage they have instead of a mouth works only for inserting into tree bark. Cicadas don’t even hurt the trees. (Not the mature trees, at any rate; saplings should be protected with cheesecloth before the cicadas emerge.)
The life cycle of the cicada is unique among insects. A nymph tunnels up from deep in the soil, climbs onto a tree trunk or a plant stem — or anything else it can reach that offers a bit of vertical clearance — and then commences to shed its exoskeleton as dramatically and beautifully as any butterfly emerging from a chrysalis. The new adult appears white, almost translucent, but its armor hardens and darkens as the hours pass. Its eyes turn red. Its intricate wings unfurl.
And then it takes to the treetops, where the males begin to sing and the females have their choice of suitors. After they mate, the female deposits her eggs into slits she makes in the bark of tender shoots. When the eggs hatch, the nymphs drop to the ground and burrow into the soil, beginning their lives in the dark. The adults live four to six weeks before they, too, fall to the ground, returning to the earth for a new purpose.
Owing to their mind-numbing numbers — up to 1.5 million per acre — periodic cicadas are louder than summer cicadas, less like a chorus and more like a fire hose blasted directly into your ear canal. At the height of the emergence, the sound appears to come from everywhere and nowhere at once, vibrating in the bones of your ears and in the fillings of your teeth. The sound can feel like a form of madness.