Spotted Lanternfly Poised To Swarm NYC: Here's What To Know

NEW YORK CITY — Their swarms inundate trees. They jump and fly as they search to lay eggs and eat sap. They've choked the life out of vineyards. They're spreading and must be killed.

The spotted lanternfly is in New York City.

The invasive insect with reddish and black spots was actually first detected in the city last year, but a growing number of recent reports indicate it'll soon become a common sight across the five boroughs.

New Yorkers should take steps — heavy ones — to help fight the problematic pest, parks officials said.

"Harming our city's wildlife is prohibited, but in an effort to slow the spread of this troublesome species, we are putting out a one-time call: if you see a spotted lanternfly, please squish and dispose of this invasive pest," the Parks Department said in a notice.

The kill-on-sight request by the Parks Department reflects fears the insect could spread and harm plants, particularly grapes.

But Julia Urban, a lanternfly expert with Penn State's Department of Entomology, warns New Yorkers against drastic measures such as spraying insecticide.

“The problem will be worse if you freak out,” she said.

'It's been spreading'

Like many New York City residents, the spotted lanternfly is a recent arrival.

The invasive pest from Asia was first documented in the United States on Sept. 22, 2014 in Berks County, Pennsylvania.

Urban said experts believe it likely came from a shipment from China on which lanternflies had laid eggs. Unlike many insects, lanternflies will lay egg masses "literally on anything," making them highly mobile and often difficult to detect until it's too late, she said.

Once lanternflies are detected in a spot, it's likely they've been there for a year or two, she said.

"It’s been spreading," she said.

The bug within a few short years spread through much of Pennsylvania, prompting major concern that its voracious appetite could harm native plant life and agriculture.

Those fears didn't fully come to pass, Urban said. The spotted lanternfly will feed on the sap of any herbaceous plant during its life cycle, but only appears to outright kill two things: the Tree of Heaven and grapes.

Tree of Heaven is common sight in New York City — a tree that grows in poor soil, along rail lines and even on rooftops. Few people will mourn the loss of such a smelly invasive tree, but Urban said they can still serve as points of spread for the spotted lanternfly.

Grapes are of much more concern, Urban said — the bugs have devastated vineyards in Pennsylvania.

“I’m really scared for Long Island,” she said.

New York City's latest bug

The spotted lanternfly officially made its New York City debut in July 2020, according to the Parks Department.

Urban and other experts weren't surprised — the insect had been spotted in surrounding areas for years.

"It’s established in Staten Island, but it’s in other areas in New York,” she said.

Awareness of New York City's latest bug broke through this week as local naturalist groups raised the alarm.

We're sounding the alert on the SPOTTED LANTERNFLY after a recent surge in Manhattan observations on @inaturalist—over 30 in just the last week. This invasive planthopper destroys plants and trees, but does not hurt humans. Kill it by swatting or squashing. pic.twitter.com/9YyIuTjMBu
— Manhattan Bird Alert (@BirdCentralPark) August 15, 2021

Sightings jumped across the city in recent weeks, according to the iNaturalist website.

New Yorkers documented more than 200 lanternfly sightings this year, ranging from Green-Wood Cemetery in Brooklyn to Central Park.

Urban said they'll likely become a common sight, potentially as soon as September. That's when the insects enter a stage when they jump and fly around to find new places to feed, she said.

“We can go and literally get tens of thousands in one area, and the other area might not get any,” she said.

The bugs often try to climb up people's legs, but Urban emphasizes they're harmless — though their claws can hurt.

“They’re sap feeders, they cannot hurt a person,” she said. “Their mouth parts cannot pierce the skin.”

The thick masses of spotted lanternflies that cover trees can appear unsettling — and Urban said within New York City it's still an open question whether they'll add stress to trees like maples.

She said stomping on the spotted lanternfly is really more about not passively spreading the bug elsewhere. New Yorkers should avoid going overboard with measures that do more than good, she said.

“What we don’t want is for people to freak out and spray more chemicals everywhere,” she said.

“People do crazy things to these bugs,” she said.

Patch writer Nick Garber contributed to this report.