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The last time the 17-year brood of cicadas emerged in Southern Maryland, Becky Zyla was an infant. Her father, bug expert John Zyla of Ridge, strapped her in to a baby seat to take her along on the hunt. In May 1996, he took to the roads of Southern Maryland to verify reports of these mysterious insects. Wherever they were heard or spotted, he plotted them on a large map.
Becky Zyla is now a junior in high school, and her father is getting ready to track cicadas again.
From May 15 through 20, the Brood II cicadas should emerge from underground, where they’ve been sucking on hardwood tree roots for 17 years, John Zyla said. They will cluster in trees to form “chorusing centers,” where the males will sing loudly to attract females.
People will definitely notice them when they come out and start singing. One billion cicadas per square mile can be expected where they emerge, said Mike Raupp, professor of entomology at the University of Maryland, College Park. “That’s a lot of cicadas,” he said.
“It might be an annoyance, but they’re not going to hurt you,” Zyla said. “They’re harmless.”
Adult cicadas can’t bite people because they have feeding tubes for mouths. Once they’re above ground, they don’t do much eating anyway. It’s all about the biological imperative to mate. Then lay their eggs. Then die.
Within a month of their emergence, they’ll all be dead and the eggs deposited into tree branches will hatch. The tiny nymphs will fall to the ground, burrow down and remain there for another 17 years, awaiting their turn in 2030.
Those studying cicadas theorize that the insects remain underground for so long to avoid predators. It is supposed that they come out on staggered schedules so predators don’t get used to an annual buffet. But 17 years goes way beyond the lifespan of several birds, which is only five to seven years, Zyla said.
And what kind of calendar are the cicadas using?
“How does an insect count? Ninety-nine percent of them come out when they’re supposed to,” he said. Seventeen years, “that’s a long time.”
“They’re one of the wonders of nature,” said Ben Beale, St. Mary’s County director for the University of Maryland Extension. “How they keep that internal clock is mind-boggling.”
Some of them come out one to four years too early or too late, though. “It’s like they miss the whole party,” Zyla said. There aren’t any others to mate with and then they die.
Some broods come out every 13 years. Some come out annually. The annual cicadas usually come out in late June. Those cicadas are generally green with black eyes. The 17-year brood about to break through usually have orange eyes and black bodies. Zyla called them “Halloweenish.”
Periodical cicadas in general are found in the eastern U.S., where there are a lot of hardwood trees. But on a regional level, the 17-year brood comes out only in certain areas. Only a few were recorded on the extreme western shore of Charles County in 1996. Their numbers were concentrated in central St. Mary’s around Route 235 from southern Lexington Park to California and north through Calvert County, nearing the county line with Anne Arundel.
Of the lack of cicadas in Charles, Karol Dyson, senior agent and area extension director for the Charles County farm extension, wrote in an email, “I was in Charles then , and in fact live in western Charles. ... There were very few cicadas! I live on a farm with woods and fields and only rarely did we hear one — maybe 2-3/day!”
Herb Reed, Calvert County director for the University of Maryland Extension, works in Prince Frederick. Regarding the 17-year cicadas’ last appearance, “I don’t remember that brood being particularly significant. I can’t remember anyone bringing them to me, and people bring me stuff all the time,” he said.
Zyla, now a defense contractor, earned a degree in wildlife management and worked at several parks in Southern Maryland. He remembers first hearing the cicadas’ song as a child growing up in Clinton.
“I remember the first time I heard it, and the woods sounded like a spaceship getting ready to take off. I think it’s a pretty cool thing,” he said.
He started studying cicadas in 1995 in time for the 17-year brood to emerge. There was little local data on them, so he decided to track them in detail in Southern Maryland.
“No one else had done it. I was really curious. I wanted to know. There wasn’t a lot of information,” he said.
The 17-year brood will be in central Virginia as well, but not on the Northern Neck of Virginia, he said. “Why do we have them in St. Mary’s County and not in the other areas? I have no idea.”
For this year’s emergence, Zyla will be mapping them again to see if they come out in areas not seen in 1996.
“What I’m going for is the boundary,” he said, to see whether it has changed. He is inviting the public’s help in tracking them through his website www.cicadas.info, the official database for cicadas in the mid-Atlantic. He also welcomes reports of where they are neither heard nor seen.
At his home in Ridge, “I lose out. I have to drive two miles up the road to see them,” he said. The dividing line seems to be at Mattapany Road. South of the road was an isolated 13-year brood, Brood 14, which came out two years ago.
Nationally, there are 12 different broods that stay underground for 17 years and three broods that stay down for 13 years.
For this year’s Brood II, once the ground temperature reaches 64 degrees, “each cicada constructs an escape tunnel to the surface of the earth,” Raupp wrote in his blog. They typically climb up trees but will ascend other objects as they shed out of their exoskeletons to form wings.
The loud sound of the cicadas comes from the males, which have tymbals. “These paired organs are located on the sides of their bodies just beneath the wings. Through muscular contractions, males vibrate the tymbal much like a drumhead to produce sound,” Raupp wrote.
Each brood has different pitches, Zyla said, and the females respond by flicking their wings.
Once mated, the female will cut slits with “a saber-like structure on her abdomen,” Raupp said, into tree branches, laying as many as 600 eggs in various branches. The tree branches will die from this, called “flagging,” and people will notice the dead branches, Zyla said.
“If you get a high population on small trees, they can cause a little damage,” Beale said.
After incubating for more than a month, the tiny cicada nymphs dive down and burrow underground to repeat the 17-year cycle, Zyla said.
While the adult cicadas are out, many predators will go after them, and dogs will eat them, too. When Brood II came out in 1860, the St. Mary’s Beacon newspaper blamed the death of several hogs on cicada consumption. On April 26, 1860, the Beacon reported, “A gentleman in the Factory district lost nine hogs this week from the same cause,” as the hogs ate the nymphs about a foot down. “In view of these facts we would suggest the penning of hogs, at least until the 10th of May, at which time, Prof. Smith says, they will emerge from the earth,” the paper said.
Raupp and Zyla said they doubted the cicadas killed those hogs because humans can eat cicadas. “There was lots and lots of folklore attached with these guys,” Raupp said.
Raupp has eaten cicadas prepared in several ways — sauteed, boiled, stir-fried, breaded and raw. “They’re good, I think, in whatever way you eat them,” he said. The key is to eat them when they’re still nymphs or immediately after they’ve burst out of their shells, like a softshell crab. The newly hatched cicadas are called tenerals.
Zyla baked a batch of Brood II cicadas 17 years ago on a cookie sheet. Like crabs, cicadas need to be cooked alive for the best results.
The ancestors of this 17-year brood were underground during the Civil War and re-emerged again in 1877 when Reconstruction of the South officially ended. Brood II came out again in 1894, 1911 and 1928.
Reported by a correspondent in the Hollywood area on June 8, 1928, the Beacon said, “The 17-year Locusts have made their appearance. So great is their song that it is deafening to one in their swarm. Orchardists should lose no time in driving them from their fruit trees for they are very destructive to same.”
When the cicadas came out again in May 1945, the Allies had just defeated Nazi Germany, nearing the end of World War II. The cicadas appeared again in Southern Maryland in 1962, 1979 and, most recently, 1996.
Brood X of the periodical cicadas are more widespread in central Maryland. Also 17-year cicadas, they last emerged in 2004, so they’ll be due to return in 2021.
Cicadas were historically referred to as locusts, a name they got for their swarms by the Puritans who landed in New England, Zyla said.