Trillions of evolution's bizarro wonders, red-eyed periodical cicadas that have pumps in their heads and jet-like muscles in their rears, are about to emerge in numbers not seen in decades and possibly centuries.
Crawling out from underground every 13 or 17 years, with a collective song as loud as jet engines, the periodical cicadas are nature's kings of the calendar.
These black bugs with bulging eyes differ from their greener-tinged cousins that come out annually. They stay buried year after year, until they surface and take over a landscape, covering houses with shed exoskeletons and making the ground crunchy.
This spring, an unusual cicada double dose is about to invade a couple parts of the United States in what University of Connecticut cicada expert John Cooley called "cicada-geddon." The last time these two broods came out together in 1803 Thomas Jefferson, who wrote about cicadas in his Garden Book but mistakenly called them locusts, was president.
"Periodic cicadas don't do subtle," Cooley said.
If you're fascinated by the upcoming solar eclipse, the cicadas are weirder and bigger, said Georgia Tech biophysicist Saad Bhamla.
"The emergence of these incredible living organisms from the depths of the Earth, their journey up the trees, it's truly a mesmerizing sight," expressed Bhamla. "It's almost like an alien species residing beneath us, only to make a grand appearance every few years."
Often confused with locusts, periodical cicadas are more of a nuisance than a threat to the economy. While they can cause damage to young trees and certain crops, it's not a widespread issue and can be managed.
Two distinct broods create a "mass invasion": 1 million per acre
The largest brood in the country — known as Brood XIX and emerging every 13 years — is preparing to swarm through the Southeast, already leaving numerous boreholes in the red clay of Georgia. This serves as a clear indication of the impending cicada takeover. The insects emerge when the ground reaches 64 degrees (17.8 degrees Celsius), a process that is happening earlier than before due to climate change, according to entomologists. Initially brown, the bugs darken as they mature.
Following the significant presence of these insects in Georgia and other Southeastern states, related cicadas that appear every 17 years will flood Illinois. This group is known as Brood XIII.
"While Brood XIX is widespread, Brood XIII in the Midwest is historically abundant and densely populated," explained University of Maryland entomologist Mike Raupp.
"When you combine those two... you would have more insects than anywhere else at any other time," remarked University of Maryland entomologist Paula Shrewsbury.
These elusive cicadas are exclusively found in the eastern United States and a few other small regions. There are a total of 15 different broods that emerge every few years, following either 17- or 13-year cycles. While these two broods may overlap in a specific area near central Illinois, entomologists believe they are unlikely to interbreed.
According to experts speaking to CBS Chicago, there will be no escaping the insects in Illinois once they emerge, expected around mid-May.
"It's going to be a massive invasion, but a peaceful one," stated Allen Lawrence, associate curator of entomology at the Peggy Notebaert Nature Museum.
The sheer numbers expected to emerge this year — averaging approximately 1 million per acre across hundreds of millions of acres spanning 16 states — are staggering. The total count could reach into the hundreds of trillions, or even quadrillions, as per Cooley.
An even larger joint emergence will occur when the two largest broods, XIX and XIV, emerge simultaneously in 2076, Cooley mentioned: "That will be the cicada-palooza."
Some entomologists believe that the high numbers of astronomical cicadas can be attributed to evolution. These periodical cicadas are described as fat, slow, and tasty, making them a perfect meal for birds, according to experts. In fact, entomologist Raupp even enjoys eating them himself, with his school publishing a cicada cookbook titled "Cicada-Licious." However, despite being a popular bird snack, there are too many cicadas for them to be completely eradicated.
"Birds all around will have a feast. They will be satisfied, and once again the cicadas will emerge victorious," Raupp stated.
Pets may also be tempted to snack on cicadas. Veterinarians have reassured pet owners that it is generally not a health risk.
"Cicadas are not toxic to pets. They do not pose a threat of stinging or biting your pet," explained Dr. Cynthia Gonzalez of Family Pet Animal Hospital in Chicago. "The main concern would arise if a large quantity is ingested, or in the case of smaller dogs, if they consume a piece of the exoskeleton, which can cause irritation to their gastrointestinal tract."
"In rare cases, an animal may experience an allergic reaction to certain components in the exoskeleton, especially if the pet has a shellfish allergy," added Dr. Kelly Cairns, a board-certified small animal internal medicine specialist.
Prime numbers and an evolutionary trick
The other way cicadas use numbers, or math, is in their cycles. They stay underground either 13 or 17 years, both prime numbers. Those big and odd numbers are likely an evolutionary trick to keep predators from relying on a predictable emergence.
The cicadas can cause problems for young trees and nurseries when their mating and nesting weighs down and breaks branches, Shrewsbury said.
Periodical cicadas look for vegetation surrounding mature trees, where they can mate and lay eggs and then go underground to feast on the roots, said Mount St. Joseph University biologist Gene Kritsky, a cicada expert who wrote a book on this year's dual emergence. That makes American suburbia "periodical cicada heaven," he said.
It can be hard on the eardrums when all those cicadas get together in those trees and start chorusing. It's like a singles bar with the males singing to attract mates, with each species having its own mating call.
"The whole tree is screaming," said Kritsky, who created a Cicada Safari app to track where the cicadas are.
Cooley takes hearing protection because it can get so intense.
"It's up in the 110 decibel range," Cooley said. "It'd be like putting your head next to a jet. It is painful."
The courtship is something to watch, Kritsky imitated the male singing "ffaairro (his pitch rising), ffaairro."
"She flicks her wings," Kritsky narrated in a play-by-play. "He moves closer. He sings. She flicks her wings. When he gets really close, he doesn't have a gap, he'll go ffaairro, ffaairro, ffaairro, fffaairo."
Then the mating is consummated, with the female laying eggs in a groove in a tree branch. The cicada nymph will fall to the ground, then dig underground to get to the roots of a tree.
Cicadas are strange in that they feed on the tree's xylem, which carry water and some nutrients. The pressure inside the xylem is lower than outside, but a pump in the cicada's head allows the bug to get fluid that it otherwise wouldn't be able to get out of the tree, said Carrie Deans, a University of Alabama Huntsville entomologist.
The cicada gets so much fluid that it has a lot of liquid waste to get rid of. It does so thanks to a special muscle that creates a jet of urine that flows faster than in most any other animal, said Georgia Tech's Bhamla.
In Macon, Georgia, T.J. Rauls was planting roses and holly this week when he came across a cicada while digging. A neighbor had already posted an image of an early-emerging critter.
Rauls named his own bug "Bobby" and said he's looking forward to more to come.
"I anticipate it will be a thrilling experience," Rauls expressed. "The cacophony of their sounds will be quite bewildering."
