The Brood X cicadas aren’t flying around anymore, but take a closer look and there are still signs of their emergence lingering.

Before they died, female cicadas laid their eggs within tree branches. This is a process called tree-flagging, where the eggs in the branches turn clusters of leaves brown. With all the rain in the Tri-State this summer, branches with these clusters may break more easily, as well.

Jennifer Ketchmark, WCPO

Dr. Gene Kritsky, dean of behavioral and natural science at Mount St. Joseph University, said there is a silver lining to this eyesore.

"Whenever you go in and prune those excess branches, the tree responds by actually producing more lush growth the following year,” Kritsky said. “While the trees look a little ugly this year, they should look spectacular next year."

Kritsky said he’s seen a lot of this tree-flagging on the west side in Delhi, Westwood and Finneytown, and on the east side in Indian Hill. Tree-flagging is most prevalent in oak trees and doesn’t hurt them in the long run; it's actually a natural pruning process, he said.

One more tip from Dr. Kritsky: Don’t sit under an oak tree that has evidence of these brown clusters. The oak itch mite feeds on cicada eggs and can bite.

CINCINNATI — Many of the Brood X cicadas across Cincinnati are dead, but before they go, they are giving the Tri-State one last gift.

Cicada carcasses are full of nutrients that are beneficial to plants, especially trees. Their bodies act as a natural fertilizer and will help nourish vegetation across the Tri-State. The plants won't bloom more or look greener, but they will be properly nourished.

"All those nutrients in the millions of cicadas that we saw will go into the soil," said Dr. Gene Kritsky, the dean of behavioral and natural sciences at Mount St. Joseph University. "Especially for those trees where they’ve clustered at the base of a tree and you just see mounds of these things."

However, cicada carcasses don't decompose easily, so they will stick around for a while, and they can smell.

Kritsky has a solution for that, though.

"If you don’t like the looks of them," he said, "one thing you can do is literally rake them away from the tree -- not far away -- and then when you mow, provided you have a mulching mower, that will hasten the decline and the smell right away.”

Kritsky said the cicada life-cycle has already started over.

Female cicadas laid their eggs in tree branches, and soon some leaves will turn brown and fall from trees. Then, cicada nymphs will hatch and fall into the soil, looking like dust falling from a tree.

From cicada tattoos to sculptures and now chocolate, a candy company is finding success with the Brood X cicada invasion.While tons of cicadas are buzzing around outside, inside Chouquette Chocolates in Maryland the insects are being air-fried and dipped in chocolate."Trust me, this chocolate will not get used for anything but cicadas," said Sarah Dwyer, owner of Chouquette Chocolates.Dwyer said there's a lot of interest from customers for her cicada confections."It's really like a chocolate-covered potato chip. It's really crunchy because we air-fry them. So, we clean them first, then air-fry them and then dip them in chocolate and you sprinkle whatever spice you want on top," Dwyer said.If real cicada chocolates aren't your thing, Dwyer has other sweet options to tantalize your tongue and still commemorate the 17-year event. She sells chocolates with creative cicada quotes, buttons and a cicada chocolate mold filled with marshmallow cream, corn flakes and candy.Dwyer opened Chouquette Chocolates about 10 years ago, and coming up with creative confections like Dr. Anthony Fauci and Ruth Bader Ginsberg chocolates is what gets the sales."I just think 2021 is a year like no other. Last year, our best-seller was Dr. Fauci chocolates, and this year, it's cicadas," Dwyer said.But if you want the chocolate-covered cicadas, you'll have to special order them online."I just thought the whole idea of having cicadas around every 17 years, it's fascinating," she said.

CNN —

Related video above: Chef Rino Roma cooks up cicada bruschetta: It's what's for dinner

The cicada symphony is coming, but cool weather is putting a damper on the orchestra.

Maybe you have never heard it before, but it can be beautiful to some and maddening to others. Scientists who study them have waited 17 years for these noise machines to emerge from their slumber.

This week's March-like weather in May is keeping many of the sound-producing insects from joining their friends on cue.

"This cold snap we're having here in the Midwest and out East is certainly delaying the mass emergence of periodical cicadas," entomologist Gene Kritsky told CNN. "Normally, we would have had cicadas emerging probably any day now," he said Tuesday.

Kritsky, who says cicadas helped him get tenure, is the dean of behavioral and natural sciences at Mount St. Joseph University in Cincinnati.

The black-and-red periodical insects usually emerge the first week in May, he said. "That mass emergence hasn't really kicked in yet," Kritsky said, but the delay is only expected to be for a few days.

Bug enthusiasts are anticipating Brood X of the periodical cicadas to be the largest emergence event since 2004. Billions of cicadas across 16 states will soon be singing and looking for a mate, covering a swath of land from Tennessee to New York.

Brood X -- pronounced Brood 10 for the roman numeral -- is one of the 15 periodical cicada broods in the U.S. Most of these periodical cicadas emerge once every 17 years, but there are a few that come out in 13-year cycles.

These special cicadas are different from the annual cicadas, which are green, brown and black with green eyes that emerge in small numbers. The periodical cicadas have a different agenda -- they come out in droves so they can survive predators from picking them off before they can mate.

Some cicadas have already emerged in north Georgia, North and South Carolina and outside Washington, D.C., Kritsky said. Warm temperatures coaxed them out of their slumber, but there aren't many of them yet because of the shift in weather.

"Much of the region -- where cicadas will emerge -- continue to have below-average high temperatures through the weekend. Monday looks to be the first day that really gets back to normal temperatures," CNN meteorologist Judson Jones said.

An unseasonably cold air mass over much of the Southeast is dropping temperatures 10 to 25 degrees below the seasonal averages. From Wednesday into Thursday, as many as 32 record cold high temperatures are expected across the South.

The latest cold snap is slowing most of the brood from joining. The cold doesn't hurt them or even kill them -- it just signals to the cicadas that it's not time to emerge from their subterranean slumber, Kritsky said.

"When that happens, the cicadas just go deeper in their tunnel where the temperatures drop," Kritsky said. "They know what to do. They've been doing it for 17 years."

The cicadas that already emerged just have to deal with the chilly weather, as they are cold-blooded. The insects rely on the air temperature and sunlight to warm them up enough to go about their singing and mating.

Normally, it takes the insects five days to harden their exoskeletons so they can fly and start singing, Kritsky explained. The cooler temperatures will slow down the process and keep the singing much quieter than the usual roar.

The males do all the singing. After a pair of cicadas mate and the female lays eggs in the tree, the nymphs drop out and burrow into the ground.

Don't worry, though. The Climate Prediction Center forecasts for next week and weekend are showing above-average temperatures, Jones said.

"If I were a betting man, I would look to have your earplugs ready to go by the end of next week," he said.

The more cicadas, the louder things can get. Parts of Baltimore, Washington, D.C., and Cincinnati are expected to be the loudest spots, Kritsky said.

For these periodical cicadas, it's all about having the right soil temperature. When the soil is at 64 degrees Fahrenheit for three days or longer, the cicadas start to emerge, Kritsky said.

The soil temperature doesn't change as quickly as the air temperature, he said. If you have some daily high temperatures in the upper 70s and low 80s, that will speed up the soil rising in temperature.

Cicadas depend on the climate and they take cues from Mother Nature to know when it's time to say hello to humans.

"Cicadas are bugs of climate. They evolve their long life cycle in response to the Ice Age, that is the current working model that we're looking at," Kritsky said. "We know that the increasing temperatures we've experienced over the last few years is causing some of the broods to actually spin-off four-year accelerations."

In the year 2000, four years before Brood X was scheduled to appear, cicadas came out early. Many died, but some in southwestern Ohio survived to form a separate group that reemerged in 2017.

The lifespan of Brood X cicadas is 17 years, from the time the eggs hatch and the nymphs burrow to the end of their life after they emerge and mate.

If you see a cicada, there is one thing you can do to help scientists -- there's an app for that.

Cicada Safari allows you to snap a photo and tag a location where you saw the red-eyed insect emerging. Experts verify each image to make sure it's a periodical cicada, said Kritsky, who created the app with the Center for IT Engagement at his university.

All the cicada needs now is its own Instagram account. The last time these appeared, Facebook was in its infancy.

Some are already starting to see signs of the Brood X cicadas emerging, and if you've seen bags on trees in your neighborhood, it's for a good reason. Carrie Engle at Valley View Farms in Cockeysville, Maryland, said there is value in putting a net over young trees ahead of the cicada swarm of 2021. Engle said cicadas can be devastating to young trees."The female cicadas, after they get together with the males, are going to slit the ends of the branches and lay their eggs in that slit, so, maybe 6 inches to a foot back, and then eventually that will break away from the main branch," she said.Mature trees aren't so much at risk. Their branches are thicker and stronger. Plus, it's difficult to climb that high to cover branches with netting. But the young tree branches are too weak for the netting to hang on and can break. Engle said you'll notice some bowing later this summer. If you're going to get a net to cover your tree, make sure the holes are no larger than three-eighths of an inch because cicadas can get through them."The cicadas are coming. A lot of people are excited about it and some are dreading it. But it's kind of a cool phenomenon when you think about it. It only happens every 17 years," Engle said.If your trees do take a beating, don't worry. Engle said it's a natural pruning that will eventually fix itself.