Brood X, one of the largest cicada broods, will emerge this summer after 17 years underground.
According to Michael J. Raupp, professor emeritus of entomology at the University of Maryland, the beetles have lurked beneath the surface since 2004, feeding on sap from the roots of plants. As soon as they are ripe, the “big brood” will emerge in 15 states, where they will spend two to four weeks in late May and early June “courting, mating, flying, driving people crazy, being eaten by everything” including people like Raupp.
The adults lay their eggs in trees that hatch 4 to 6 weeks later in more than a dozen states. Their offspring will return underground by 2038.
They’ll make quite a bit of noise too. According to Raupp, cicadas can emit between 80 and 100 decibels of noise, which is the same as a low-flying airplane or lawnmower.
Periodic cicadas of Brood X:Has been underground for 17 years, ready to surface again and make some noise
Here’s everything you need to know about Brood X:
What is a brood?
Periodic cicadas appear in large groups called broods. There are 12 broods of cicada that appear every seven years and three broods that appear every 13 years, Raupp said.
Two broods appear to be extinct, including Brood XI, which was last observed in Connecticut in 1954. Almost every year there will be periodic brood somewhere in the country.
“A brood is a geographically different massive formation of periodic cicadas that occurs either every 13 years or 17 years,” said Raupp. “Depending on the location and year, there are several of these broods.”
Why is it called “Brood X”?
While the name sounds ominous, the story behind the name is pretty simple. Broods are distinguished using Roman numerals, and Brood X is the tenth brood that experts have tracked.
What is special about Brood X?
Brood X is one of the largest and most widespread groups of periodic cicadas. Raupp said they can be found from northern Georgia to New York, west to the Mississippi, and the Midwest. He estimated that there can be up to 1.5 million cicadas per acre, bringing the total breeding population to trillions.
“Lots of people will see cicadas,” he said.
Why do they appear every 17 years?
Why cicadas spend so long underground is “one of the great secrets of biology,” according to Raupp, but their “very unique and very bizarre” life cycle is likely a strategy for avoiding predators.
Cicadas are larger than many of their insect relatives, and their food source is low in nutrients, which means they have to spend a long time developing, Raupp said. As they get bigger, they can produce more offspring, which is the key to “predator satiety”.
“You will have so many offspring that will appear at the same time. In synchrony, you will fill all the bellies of any predator that wants to eat these things, and there will still be enough left to perpetuate the species,” said Raupp.
Raupp added that their long lifespan also helps them avoid predators that don’t live long enough to remember they exist.
Are cicadas dangerous?
Raupp said cicadas pose no threat to humans and instead provide a “spectacular teaching moment”.
“They will not harm your pets or carry young children away,” he said, although he cautioned pet owners not to overly indulge their animals.
If the sudden emergence of trillions of insects is too big, Raupp recommends leaving the area where Brood X is located.
Older trees shouldn’t have a significant impact, but Raupp said those looking to transplant small seedlings should wait until fall to avoid damage to small trees from cicadas laying eggs. He also recommended the use of 1 cm mesh over young trees, but cautioned people against using pesticides that could be ineffective and harmful to other species.
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