The 17-year-old sex-crazed cicadas of Brood II have started to stir in Staten Island.
Historically, large numbers of these periodical cicadas have spent their short but dramatic adulthoods in the borough, but they might be harder to spot elsewhere in New York City.
The noisy creatures started emerging by the hundreds last week in certain parts of Staten Island, said Edward Johnson, director of science at the Staten Island Museum. But the insects are not likely to come out in droves in Brooklyn, Queens, the Bronx and Manhattan, Johnson added.
"They don't fly very far as adults, and so are unlikely to colonize other boroughs from Staten Island," he said. [ Ewww! 6 Crazy Facts About Cicadas ]
Brood II is one of the distinct cicada populations that only matures every 13 or 17 years. Known as periodical cicadas, they belong to the genus Magicicada, and they can be found only in the eastern half of North America. Brood II's range extends from Georgia to Connecticut and it began its emergence earlier this month.
Their loud mating calls and carpet of corpses may come as a nuisance to some, but each emergence is exciting for entomologists studying the mysterious, long-lived insects — they spend most of their lives in an immature stage. The cicadas coming out of the ground now were born in 1996, meaning they're the first Brood II generation to be greeted by Twitter and Flickr, which make it possible for people to socially share their pictures of the insects. Radiolab's Cicada Tracker and Magicicada as well allow citizen scientists to report their sightings in real time.
Mapping where these 17-year cicadas emerge could offer new insights on land use, climate change and the bugs themselves. The cicadas' long subterranean youth, which may be the longest of any known insect, means it's difficult for scientists to study their life cycle.
Geographically, the 17-year brood populations fit together like puzzle pieces. Brood II is almost like the keystone, since its range borders that of many other broods, University of Connecticut cicada expert John Cooley said earlier this month. Scientists think they might be able to learn about why different broods evolved by studying their boundaries.
For Johnson, the emergence will give him a chance to show off the Staten Island Museum's collection of cicadas, the second largest in the world. He said he has dim memories of the Brood II emergences on Staten Island in 1962 and 1979, but better recollections from last time, in 1996.
From that year, Johnson recalls "lots of cicada song and activity in the woodlands, lots of media attention, and my youngest son was born three months before the emergence, so he is a 'cicada baby,' and gets to measure his life in cicada years."
To be fair to the creatures, they're not swarming or invading or coming out of hibernation. They've been sharing the environment with East Coasters this whole time — they've just been underground sucking roots. The insects might only seem like a plague because of their numbers. Some scientists estimated up to 30 billion Brood II adults would make their debut this year. [ Ouch: Nature's 10 Biggest Pests ]
Researchers think this is all part of a survival strategy known as "predator satiation," in which a huge percentage of the population is expected to be eaten, Popular Science reported. Cicadas are clumsy and they don't have defenses for stinging or biting their predators, but their numbers alone will be enough to ensure the brood survives. In other words, there will still be lots of six-legged lingerers after dogs, cats, birds and even some adventurous humans get their fill.
But even if they do dodge their enemies, the clock is ticking for emergent cicadas.
After a dark 17-year juvenile period underground, hormones and warm soil temperatures (64 degrees Fahrenheit to be precise) send the crunchy cicada nymphs above the surface. The insects then shed their brown exoskeletons and spend their few weeks of adulthood mating and laying eggs in tree branches. Then, they die, leaving their big bodies to litter the ground, while the newly hatched babies will make their way down to the dirt to continue the cycle. The Brood II generation born this year will go on hiatus until 2030.
Cicadas' short act above the surface is made more theatrical by their racket. Males make species-specific mating calls by vibrating a white, drumlike plate, or tymbal, on either side of their abdomens. These chirping and clicking noises can be heard by females up to a mile (1.6 kilometers) away. Standing near an especially loud chorus of cicadas can be like standing near a motorcycle, with a noise reaching up to 100 decibels.
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