In the spring of 2024, weeks after the April 8 total solar eclipse, two broods of occasional cicadas will emerge, and billions of insects will begin covering parts of the U.S.
The emerging cicadas are Brood XIII — a group of 17-year-old cicadas — and Brood XIX — a group of 13-year-old cicadas. This is the first time in 221 years that two broods will be above ground at the same time, and the groups of insects will also overlap geographically.
Some are calling the coming double whammy the “cricket apocalypse,” conjuring up visions of a world infested with insects in every nook and cranny. PEOPLE spoke to two insect experts about the appearance of two cicada broods, who assured us the result of the double appearance won’t be a scene straight out of a sci-fi movie. In fact, the double appearance could become a cherished “generational memory”.
Read on to find out what Dr. Gene Kritsky—a professor emeritus of biology at Mount Saint Joseph University who literally wrote the book on the appearance of double cicadas in 2024—and Steve Nicholls, an entomologist and wildlife filmmaker, have to share about the appearance of double cicadas this year. spring and where the bed bug will overlap.
Map of cicada occurrences expected in the spring of 2024. The red dots represent the expected Brood XIX occurrence areas and the blue dots represent the estimated Brood XIII occurrence areas.
Gene Kritsky, University of Mount St. Joseph
Where will the two cicada broods come out?
Brood XIX, also known as the “Great Southern Brood,” is “a really big brood,” says Nicholls, covering much of the southeastern US. The estimated spawning areas of Brood XIX are shown in red dots on the map above.
Litter XIII “is called the Northern Illinois brood, which, unsurprisingly, is in northern Illinois and nearby areas and is a much smaller litter,” says Nicholls. The map above shows Brood XIII’s estimated spawning areas with blue dots.
When will the crickets spawn?
“We expect periodical cicadas to start showing up in the last week of April in the southern end of their range, which is in northern Louisiana, northern Mississippi, northern Alabama and Georgia. This could happen as early as the last week of April into the first week of May ” says Dr. Gene Kritsky of the 13-year-old cicadas in Brood XIX.
According to Nicholls and Dr. Kritsky, soil temperature determines when crickets emerge. Once the soil temperature reaches 64 degrees Fahrenheit, the beetles begin to emerge from the soil. This means that two litters of crickets will not appear at once.
As spring progresses further north and warms the soil, crickets will begin to emerge in these areas.
When you get to northern Illinois, the epicenter of Brood XIII, “you’re looking at the last week of May” for an appearance, Dr. Kritsky says. He adds that in 2007, the litter started coming out on June 7.
“And emergence is not like all or nothing; it takes two weeks for all the crickets to emerge in a certain place,” he adds.
Since crickets live for about a month after they start emerging and take about two weeks to fully emerge in an area, crickets will be present in their outbreak areas for a total of about six weeks.
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Where will two cicada broods overlap?
“There’s been a lot of hype and concern about this overlap zone,” Dr. Kritsky tells PEOPLE, adding, “I think people expect to see twice as many cicadas, a cicada apocalypse, or Armageddon.”
He assures that the reality of the overlap zone is far less dramatic: “It’s a very narrow area. What’s more, it’s at the extreme edge of both litters. And at the edges of the litter, that’s where the numbers aren’t that big.”
Based on the estimated area of occurrence of each brood — detailed on the map above — brood XIII and brood XIX are most likely to overlap in central Illinois toward the state border with Indiana.
“Springfield could be a tourist hub for crickets,” jokes Nicholls of the overlapping area, adding, “Where they overlap, there’s going to be a lot of insect talk.”
“We don’t know the exact distribution, so it’s possible that a few areas will get double-occurrences. But I think eventually what will happen is that you can drive a lot further and see crickets all the way,” he said. he adds.
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A tree covered with periodic crickets.
Gene Kritsky, University of Mount St. Joseph
What is a periodic cicada?
“There are 3,000 species of crickets around the planet, but only a few of them are periodical species,” says Nicholls, who recently consulted on The life of real bugsthe new Disney+ original series from National Geographic.
Period cicadas mature underground for a long time before emerging; depending on the species, this period can be 13 years, like litter XIX, or 17 years, like litter XIII.
“There’s one in Fiji that comes out every eight years. And one in India, it’s called the Cicada World Cup, because it comes out every four years, at the same time as the soccer World Cup,” says the entomologist.
“To summarize the life cycle, the adults mate and lay eggs. The female has a tip of a saw-like abdominal structure, which she uses to saw a small slot in the stem of the plant where she lays her eggs. After the cicadas leave, you can see egg scars all over the branches. Those eggs hatch and then the nymphs, the little tiny creatures, hatch,” adds Nicholls.
Newly hatched nymphs “literally jump from the tree to the ground,” he explains. “And then they dig underground and stay there, with the ones we’re talking about, either for 13 years or 17 years.
After periodical cicadas are fully grown, they sit close to the surface and wait for the soil to reach the appropriate temperature.
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What is a cicada brood?
“A brood is like a year class,” explains Dr. Kritsky, adding that entomologist Charles Marlatt coined the term cicada in 1893.
According to Dr. Kritsky, Marlatt decided, “Any 17-year-old cricket that emerges in 1893 we will call Brood I. A 17-year-old cricket that emerges in 1894 is Brood II, and so on. A 13-year-old cicada, if came out in 1893, that was Brood XVIII, and so on. The first 17 issues are reserved for 17-year-old cicadas. The next 13 issues are for 13-year-old cicadas.”
“When you just say Brood XIX, you immediately know it’s a 13-year-old cicada,” he adds.
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A close-up shot of a periodic cicada.
Gene Kritsky, University of Mount St. Joseph
Are double occurrences of crickets rare?
Although Brood XIII and Brood XIX haven’t appeared at the same time in 221 years, “double appearances happen a lot,” says Dr. Kritsky
“There are 12 different broods of 17-year-old cicadas and three different broods of 13-year-old cicadas. Twelve times three is 36. So in the year 2021 it can happen more than 30 times. But what’s unusual about this is that there is a zone of overlap, of potential overlap. For example, when Brood IV appeared together with Brood XIX in 1998, they were hundreds of miles apart,” he adds.
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A tree with dead branches caused by cicadas laying eggs on the tree.
Gene Kritsky, University of Mount St. Joseph
Do cicadas pose any danger to humans?
“Crickets don’t spread disease. They don’t bite people. They’re not a sign of dirt. They don’t have mouth parts to chew; they won’t chew your plants. The only damage they can do is when the female lays her eggs in tree branches; sometimes those branches will break and the leaves will turn brown. But for a mature tree, it’s not a problem. It’s like a natural pruning. And the flower set next year will be even bigger,” says Dr. Kritsky, calling the beetles “an unimportant pest at all.”
According to Dr. Kritsky and Nicholls, cicadas are often a boon, especially to other animals.
“Once the cicadas start flying around, they become food for all kinds of opportunistic predators: dogs, cats, birds, all kinds of birds, turtles, snakes, squirrels. I’ve seen deer eat these things. And that’s part of the survival of cicadas. They actually overwhelm their potential predators with so much food that the predators get tired of eating them, and there are still millions left over,” says Dr. Kritsky.
When billions of insects begin to die and leave carcasses behind, the clumps can rot and stink in the rising spring temperatures, but even then, the crickets are fine.
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“You’ll never forget that smell. It’s a fragrant memory. As these smelly carcasses start to decompose, those nutrients go into the soil around the trees, creating a supply of nutrients for the tree and the crickets. So they do a lot of good for the ecosystem,” adds Dr. Kritsky.
He encourages people not to be afraid of crickets — or to kill them with pesticides because they are not effective against insects — but to embrace the opportunity to see an amazing natural event.
“If you’re lucky enough to have this in your backyard, bring the kids, go there and watch this. It’s like having a special David Attenborough in your backyard. It creates a generational memory,” he says.
He also encourages people to document their cicada sightings on Cicada Safari, an app Dr. Kritsky helped create to collect data on cicadas and better understand the bugs.
Categories: Trends
Source: HIS Education