Brood X cicadas are now emerging in the Mid-Atlantic

Billions, if not trillions, of cicadas have emerged from below the ground in the Mid-Atlantic, a plague of biblical proportions that occurs only once every 17 years. In fact, there are so many cicadas that they appear on weather radars in Loudoun County, Virginia, as rain.

In a tweet posted on Monday, June 7, Lauryn Ricketts, a meteorologist with Storm Team 4, said it was so likely that cicadas were being picked up by the radar beam. “THIS is not rain, not ground clutter,” said Ricketts, referring to a picture of the fuzzy patches on the radar imagery. The patches occurred near the radar.

Those fuzzy patches are, in fact, cicadas, according to Kyle Pallozzi, a Virginia-based meteorologist for the National Weather Service (NWS). Pallozzi said the NWS actually has a weather radar in Sterling, a census-designated place in Loudoun County, in the same region as the radar map Ricketts tweeted about.

The beams that the weather radars send out rise the further they travel from the machines. Therefore, the beams are picking up newly emerged cicadas on the ground near the radar in Sterling.

But as the beams’ height increases away from the ground, the beams pick up fewer and fewer cicadas. This may explain why the fuzzy patches on the map are so close to where the actual radar is, said Pallozzi.

Although the cicadas are emerging in high enough numbers for radars to detect them, it’s still easy for meteorologists to distinguish between actual weather events and cicadas because of the Hydrometeor Classification Algorithm. The NWS can use this algorithm to determine whether a radar beam is detecting rain, hail, snow or something biological, such as cicadas.

On Saturday, June 5, the NWS’s Baltimore-Washington accounted tweeted that its radar was detecting “a lot of fuzziness,” which it attributed to the emerging cicadas.

“Brood X” is now emerging

The brood of cicadas currently emerging in the Mid-Atlantic is called “Brood X.” In 1898, broods were assigned a Roman numeral depending on their location and the calendar year when they emerge. Numbers one to 17 denote 17-year cicadas, while numbers 18 to 30 follow a 13-year cycle.

Brood X is the largest of the 17-year cicadas, which are spread across 15 states, from Indiana to New York. They were first observed on May 9, 1715 by a minister at Pennsylvania’s oldest church. According to his journal, “some singular flies came out of the ground.”

Every emergence of Brood X has since been documented. The current emergence is the 19th.

Cicadas are known for the loud, buzzing noise they make when they emerge from the ground. Only males produce that noise, which is actually a mating song, using organs on either side of the body.

Those organs, called tymbals, amplify the sounds the cicadas produce in their hollow abdomens. It’s because of these organs that cicadas can “scream” at around 96 decibels. That’s louder than jets flying into Heathrow Airport in the United Kingdom, said Gene Kritsky, who has studied periodical cicadas for almost 40 years.

In fact, cicadas are so loud that prolonged exposure to their noise can lead to permanent hearing damage. (Related: New research concludes that loud music played during spin classes can cause long-term hearing damage.)

Scientists have long believed that cicadas have an internal clock dependent on environmental cues, which signal to them when it’s time to emerge. For instance, changes to the flow of fluids in the tree roots allow cicadas, which burrow underground, to mark the passage of time. But what scientists still haven’t figured out is how cicadas are able to remember what year it is.

But of the 3,400 species of cicadas, only seven are actually periodical. This means they spend 13 or 17 years just buried underground before emerging en masse to mate and die. Experts thought their long life cycles evolved in the past 300,000 years as an adaptation to the Ice Age. Since 2000, two more periodical species have been discovered in Fiji and India, with eight- and four-year life cycles, respectively.

Learn more about Brood X and cicadas at Environ.news.

Sources include:

StrangeSounds.org

Insider.com

TheGuardian.com