Some of the northeast and central parts of the U.S. are about to experience the kind of plague you’d read about in Exodus. Or see in a plot-twisty M. Night Shyamalan movie. Billions of cicadas will erupt from the ground and swarm about for their once-every-17-years mating cycle. And not only are the cicadas about to put on one heck of a show, but they will also enjoy one heck of feast.
NBC News reported on the incoming cicada swarm, which entomologists have dubbed Brood X. Brood X, or Brood 10—the labeling for cicada broods in the U.S. uses Roman numerals—is one of the 15 Great Easter Broods. And while it’s one of many, it stands out for its enormous range and concentration.
They're coming! This is the year of the 17-year cicada in our area. There will be trillions of them in early summer. They are harmless. They are loud. They are high in protein, if you're into that. They don't social distance. It's a phenomenon of nature to be enjoyed. Can't wait! pic.twitter.com/WR5qWCXq3m
— Fairfax County Parks (@fairfaxparks) March 4, 2021
The last time Brood X exploded from the earth was in 2004; a year when Snoop Dogg’s “Drop It Like It’s Hot” contended for most popular song, and Napoleon Dynamite was in theaters. Since then, the brood’s been lying in wait, drinking sap from tree roots, twigs, and branches for sustenance.
Beginning in late April or early May, however, whenever the ground grows warm enough, Brood X will burst forth, and swarm through a dozen states; including all of those that contain yellow in the map below. (The USDA Forest Service made the map, which shows which broods will swarm during which years.) The young cicadas, or “nymphs,” will first shed their skins, transforming into adults. They’ll then have just a few weeks to sing for mates, spawn, and die.
This form of reproducing makes cicadas a periodical genus; that is, a genus where all members have the same, extra-long life cycle, culminating in a mass mating fest. NBC News notes these periodical creatures are incredibly rare, with only one other type choosing the same strategy.
As for why cicadas have this unique strategy, that likely has to do with how it evolved over the past few millions years.
“During the glacial periods [of the past few million years], we think that they probably extended their life cycles, because the growing season was too short to complete development at their previous time,” Chris Simon, a cicada researcher and professor at the University of Connecticut, told NBC News. “That favored individuals that came out together, because they survived better,” the researcher added. Although, as is made abundantly clear in the BBC Earth video above, “surviving” in this case involves a whole lot of getting eaten.
Feature image: Katja Schulz