Spotted Lanternflies are back. You should still kill them.

See it, crush it, report it. That’s been the spotted lanternfly’s mantra of summers past, and the conspicuous critters are back this year, despite New Yorkers’ best efforts.

Native to parts of Asia, the spotted lanternfly was first seen in the United States almost ten years ago, when it was found at a Pennsylvania landscaping company that imported stones from abroad. It arrived in New York in the summer of 2020.

At this time of year, the spotted lanternfly is in its early nymphal stage, which takes place immediately after hatching. The tiny black insects are dotted with white spots during this stage, before developing their iconic gray and red coloration as adults in July.

Why it’s important to kill lanternflies

The Ministry of Agriculture strongly encourages people to stomp, squash or swat lanternflies when they see them. Officials have been recruiting residents along the East Coast for years to join the effort.

That’s because while spotted lanternflies are harmless to humans, they are an invasive species that can cause widespread economic damage, primarily by damaging plants.

Julia Urbanan evolutionary biologist in the department of entomology at Penn State, has been studying lanternflies for decades.

She said one 2019 report from the Penn State College of Agricultural Sciencesestimating that the bugs could cause $325 million in economic losses annually in Pennsylvania alone had proved exaggerated.

The report analyzed an infestation in South Korea that affected the growth of apple, stone fruit, timber and ornamental trees, whose Pennsylvania counterparts fared better than expected against the insects.

But she said the state’s vines, another preferred food source for the spotted lanternfly, had been badly infested and Pennsylvania growers had recorded reduced yields since the arrival of the beetle.

And the threat to New York’s much larger wine industry is even greater.

“The spotted lanternfly is knocking at the doors of vineyards in Long Island and the Finger Lakes region,” Professor Urban said. “I’m afraid if it gets into these vineyards, the volume will kick up a notch in terms of economic impact.”

Bruce Murray, 67, owns Boundary Breaks Vineyard near the Finger Lakes in Lodi, NY. He noted that spotted lanternflies had been spotted in Ithaca, just 25 miles away, and said his growers were looking forward to their arrival.

“Everyone is hypervigilant about this, and we have been for almost two years now,” Mr Murray said.

While it’s still too early for Mr. Murray to break out the insecticide, he’s prepared by cutting down Tree of Heaven plants, an invasive species from China that lanternflies feed on, whenever he sees them.

How gardeners can fight back against lanternflies

Neal Weissman, 68, is the president of the Roosevelt Island Garden Club and helps oversee the Manhattan borough’s large community garden.

As a member of the garden’s pest control committee, he wanders between plots with a handheld vacuum and vacuums up any lanternfly nymphs he encounters, hoping to keep the populace at bay.

The daily vacuuming, Mr. Weissman said, “began to give me nightmares.”

He said he had noticed an “exponential” increase in the number of lanternflies and his traps had caught the same number in one hour as they caught in an entire weekend last year.

Grape growers on Roosevelt Island, which sits in the East River, are already seeing a decline in plant health this season, with some gardeners removing their vines entirely to curb the insect’s spread.

Pia Doane, 77, has been gardening on Roosevelt Island for over 30 years. Mrs. Doane swears by a vegetable oil-based spray called Gronnsape to tackle the bug: a cleaner who, like her, hails from Scandinavia.

Still, her languishing champagne vines have been infested with lanternflies, and she’s considering throwing in the towel and giving up grapes altogether this year.

“My poor vines,” said Mrs. Doane. “It’s very frustrating.”

Mr. Weissman has considered using mantises, one of the lanternfly’s few natural predators, to control the population. But he said those available for purchase are non-native and members of his garden’s board had opposed the introduction of another invasive bug.

Known predators also include wheel beetles, spiders and some birds, though none of them seem to be making a dent in the population, Professor Urban said.

The club has weighed in with tape to catch the lanternflies, but that risks ensnaring beneficial insects, such as pollinators, and even small birds.

For now, the island’s gardeners are sticking to other pesticide-free strategies, including small vacuum cleaners and special tree traps specifically targeting lanternflies.

Do lanternflies really have to die?

Those hesitant to kill lanternflies they see should know that the choice is squash or spread, experts say.

Base-level eradication is unlikely to occur, so containment is the goal. By killing the ones you see, they and their eggs cannot follow you in your car or even on an airplane.

The insects multiply readily in the wild, and they’ve even appeared on cargo flights to California, where an infestation would be economically “devastating,” Professor Urban said.

California is home to the nation’s largest wine industry, contributing $73 billion to the state and $170.5 billion to the U.S. economy, according to a report commissioned by the Wine Institute and the California Association of Winegrape Growers.

“I like them, and I don’t like killing them either,” Professor Urban said. “But killing them by stomping is better than destroying them with pesticides.”

As global supply chains become increasingly intertwined, the environmental impact of trade continues to grow. Invasive species introduced through imports, such as the spotted lanternfly, will have to be controlled with means that may feel inappropriate to some.

Yet there is an affinity with the spotted lanternfly. “These are little gems of science,” Professor Urban said.