Amazing details about the buzzing insects set to storm the United States this spring
Brood X will appear in 14 states
When the soil about eight inches below the surface reaches 64 degrees this spring, cicadas from Brood X will start to claw their way towards the light. They’re expected to emerge by the billions across 14 states, with the epicenter in the District of Columbia, Maryland and Virginia, reports Darryl Fears for the Washington Post.
Brood X is one of 15 broods of periodical cicadas—groups that emerge from the ground on the same time cycle—in the U.S. Twelve of those broods operate on 17-year cycles and the other three poke their heads above ground every 13 years. Researchers trying to map the geographic extent of Brood X encourage anyone enthusiastic about recording their sightings to use the Cicada Safari app. However, if you do go the citizen scientist route, be careful to differentiate the bona fide Brood X emergence from stragglers. In the world of periodical cicadas, stragglers are any individual insects that fall out of sync with their brood’s emergence schedule. Straggler emergences tend to be patchy and scattered compared to the main emergence. Brood X’s 2021 emergence is likely to have even more stragglers than usual because two other adjacent broods have emergence schedules that are four years before and after it, according to researchers at the University of Connecticut. So, if a smaller, lower density patch of cicadas crops up, especially in an area at the limits of Brood X’s range, it’s possible the bugs may not be from Brood X at all.
Brood X is a muse
Back in 1970, three cycles ago, Brood X’s buzz-saw-like calls inspired Bob Dylan to write the song “Day of the Locusts.” Dylan heard the cicadas while receiving an honorary degree from Princeton University and the insects inspired these lyrics:
As I stepped to the stage to pick up my degree
And the locusts sang off in the distance
Yeah, the locusts sang such a sweet melody
Oh, the locusts sang off in the distance
Yeah, the locusts sang and they were singing for me
The 1936 Ogden Nash poem “Locust-lovers, attention!” was also inspired by Brood X. The work was first published in the New Yorker and was later collected in Nash’s book I’m a Stranger Here Myself. Here’s a snippet:
Overhead, underfoot, they abound
And they have been seventeen years in the ground.
For seventeen years they were immune to politics and class war
and capital taunts and labor taunts,
And now they have come out like billions of insect debutantes
Cicadas are not locusts
Dylan and Nash shared the misapprehension that the periodical cicada is a type of locust. It is not.
Locusts are a type of short-horned grasshopper and belong to the order Orthoptera along with all other grasshoppers and crickets, while cicadas are Hemipterans which are considered “true bugs” and include aphids and planthoppers.
But, at least in the U.S., this taxonomic distinction has not stopped people from calling cicadas locusts. As Max Levy reported for Smithsonian last summer, early colonists saw hordes of emerging cicadas and quickly misidentified them as locusts. “They were thought of as a biblical plague,” John Cooley, an assistant professor in residence at the University of Connecticut, told Levy. Indeed, a group of cicadas is still referred to as a plague or a cloud. “The question I get the most is ‘How do I kill them?’” Cooley told Levy.
Cicadas have one of the longest insect lifespans
The 13- or 17-year lifespan of periodical cicadas is one of the longest of any insect, but only a tiny fraction of that time is spent above ground. The rest of a periodical cicada’s life is spent underground as a nymph feeding on liquid sucked from plant roots. Over their many years beneath the soil, the nymphs shed their exoskeletons, a process known as molting, five times.
Writing for National Geographic, Amy McKeever reports that the nymphs count the years by detecting the uptick in fluid flowing through the roots they feed on that occurs during each year’s spring growing season. After 13 or 17 cycles, periodical cicadas wait for the soil temperature to reach around 64 degrees before digging their way back to the surface.
Once topside, the nymphs climb up into the trees where they proceed to plant themselves on a branch and transform into winged adults by once again shedding their exoskeletons. At first, the red-eyed adults are a ghostly white with soft, curled-up wings unfit for flight, but their bodies soon harden and turn black and the now rigid wings can finally float the chunky two-inch bug into the air.