There are currently four periodic cicada broods on Long Island, all of which are said to arise in different years. There, as elsewhere, women lay their eggs in tree crevices. In midsummer, newly hatched nymphs crawl over the trunks, dig themselves into the ground and find a root to suck on. There they get bigger and notice the changing seasons until 17 winters have passed – their cue to come up again.
Often, however, the world is less patient about it. Roads and buildings can literally trap entire populations underground – a place on Long Island where the insects once thrived is now “a Walmart with a large parking lot,” said Dr. Simon. Even before they are sealed by asphalt, they generally condemn the felling of trees they rely on for food. Because of this, they also find it difficult to survive in places that have been converted into golf courses, playing fields and cemeteries.
Over the past century, news outlets tracking the effects of Brood X on the people of Long Island have also shown how land use there has changed over time. In 1919, farmers in Farmingdale and Massapequa reported cicada damage to their fruit trees. Seventeen years later, in 1936, the Times warned motorists that the cicadas coming from the woods by the roadside could clog their radiators. Until 1987, Long Islanders were cited as expressing amazement – along with concern for their lawns – when the insects broke out of their yards.
Farmingdale and Massapequa “are no more farmland or open space,” said Jody Gangloff-Kaufmann, an entomologist at Cornell University and a Long Island resident. “You are just home home home home.” Pesticide use and pollution could also have contributed to the declines, she said.
Once the numbers drop, the final blow can be done by predators – including introduced species that often lack predators of their own and can throw food webs off balance. In 2016, Dr. Bonaros how alien European starlings and English sparrows chased the sediment of Brood V and also disappeared from Long Island. “They’re really tearing them down and destroying them,” he said.
As with insect declines on a larger scale, experts still find some elements of Brood X’s exhaustion to be mysterious. For example, Dr. Simon said she wasn’t sure why it had largely disappeared from Connectquot State Park, which has remained untouched by development.
But it’s likely the same combination of known and unknown factors that drove two other Long Island broods, Brood I and Brood IX, to extinction prior to the 1980s. And due to his recent performance, Brood V, which was previously picked up closer to the island’s North Fork, may also not show up in the near future, she said.