They're here: Spotted lanternfly makes its way to the Hudson Valley

After first being detected in Pennsylvania in 2014 and then hopping its way through New Jersey, the destructive plant-sucking Asian insect known as the spotted lanternfly is now firmly established in Westchester, Rockland and Orange counties and other parts of the Hudson Valley.

In Pennsylvania, the lanternfly devastated certain crops, especially whole acres of grape vineyards, and that's the concern in New York, where the grape and wine industry has an estimated value of $300 million, according to the state Department of Agriculture and Markets.

The spotted lanternfly (Lycorma delicatula), also known as Chinese blistering cicada, is a plant hopper native to China and Southeastern Asia that uses specialized mouth parts that can pierce a plant and suck up sap. Both nymphs, which emerge in spring, and the adults feed this way, on leaves, stems and trunks.

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Piercing the plant’s tissues and feeding on the sap weakens the plant, causing it to ooze and weep, which may result in a fermenting odor and a gray/black trail on the bark. Spotted lanternflies also excrete honeydew while feeding, which over time may encourage the growth of sooty mold.

Spotted lanternfly nymphs are able to feed on more than 70 different plants, including willow, maple, poplar, sycamore and fruit trees, while the adults prefer tree of heaven (Ailanthus altissima) and grapevine (Vitis vinifera). 

What do they look like?

Spotted lanternfly adults, which have red hind wings with black spots, a black head and a yellow abdomen with black bands, are quite colorful when their wings are displayed during hopping. Their grayish forewings have black spots with a black bricklike pattern on the tips.

The first nymphs to develop are wingless and black with white spots, while the final nymph stage turns red. Adult males are slightly smaller than the inch-long females. Adults and nymphs commonly gather in large numbers on host plants to feed and are easiest to see at dusk or at night. There is one generation per year, with adults developing in July, laying eggs in fall and overwintering as eggs.

While they can cause plant death, they are not poisonous and do not bite or sting humans. They feed exclusively on plants.

According to Cornell’s New York State Integrated Pest Management Program, infestations have been reported in 13 states – most heavily in Pennsylvania, New Jersey, Maryland and Delaware, along with New York (including New York City, Ithaca, Long Island and the Hudson Valley), Virginia, West Virginia, Connecticut (Fairfield County), Massachusetts, Ohio, Indiana, North Carolina and Michigan.

“Over the next two to three years, residents should expect them to build up in the Lower Hudson Valley region,” says Senior Extension Associate for Ornamental Crops Brian Eshenaur, of Cornell’s New York State Integrated Pest Management Program and one of the state’s leading authorities on spotted lanternfly (SLF).

“We have them in Westchester, Rockland, Orange and now Ulster,” he says. “Rockland has the most at this point,” with infestations seen in Orangeburg and Sloatsburg.

Most recently, SLF infestations have been seen in Rockland County in Nyack and Kakiak Park in Montebello, according to Kristen Ossmann, horticulture resource educator for Cornell Cooperative Extension of Rockland County in Stony Point.

“It’s kind of a moving front,” coming up from New York City, where they were first seen in a Staten Island park in 2020, Eshenaur says.

“In residential areas, they could be on trees and it can be pretty dramatic,” Eshenaur says. “They can completely cover a tree so that you can’t see the trunk, and they can be a nuisance in the back yard.”

In general, people should not panic, he adds. “We think we’re pretty well set up for it in the Hudson Valley.” Pennsylvania horticultural experts “have shared lots of information, and they’ve figured out ways to live with this insect,” Eshenaur says.

“These insects are not a threat to the health of our shade trees,” he says.

Where have they been seen?

In Westchester, the spotted lanternfly was seen at the county airport a “couple of months ago” and sightings have been reported at Untermyer Gardens in Yonkers as well as Scarsdale and Ossining, says Community Horticulture Educator Amy Albam of Cornell Cooperative Extension of Westchester County in Elmsford.

“It’s such a moving target,” she says. “It’s definitely in Westchester County and we’ve had numerous sightings throughout the county.” Cornell-Westchester is telling callers to follow the New York State Agriculture and Markets guidelines and report sightings to the department’s website (see box).

Senior Agriculture Resource Educator Jim O’Connell of Cornell Cooperative Extension Ulster County in Kingston reports seeing a“heavy concentration in Orange County, west toward Sullivan County and close to New Jersey and Pennsylvania.”

“There are a lot of vineyards down that way,” he says, and in July they turned up in a trap that was set for them in an Orange County vineyard. Traps have been set throughout the Hudson Valley.

In Ulster, an infestation has been reported near the Hudson Valley Rail Trail in Highland, O’Connell says.

To track the lanternfly, “we’re doing some general scouting, making farm visits and scouting areas around vineyards,” he says.

So far Dutchess and Putnam counties have not been affected.

“At this point, to my knowledge, we have no reports of it in Dutchess County, but it’s only a matter of time,” says Community Horticulture Resource Educator Joyce deVries Tomaselli of Cornell Cooperative Extension Dutchess County in Millbrook, who manned a booth at the Dutchess County Fair with a large spotted lanternfly display. “Anecdotally, I had four people tell me that they saw one and they squished it.”

Hudson Valley vineyards are particularly vulnerable at this time of year because the adult lanternfly populations are peaking and at their most active in late summer and early fall, just as the grapes are ready for harvest, O’Connell says.

Further, the flies will continue to feed on the grape vines after the grapes are harvested, and vineyard managers tend to not be looking at their vines after the harvest, Eshenaur explains. “They’re focused on the harvest and making the wine.”

Other crops, including hops, blueberries and stone fruits, may also be vulnerable, he says. “They will occasionally feed on apples, but we have not seen them do any real damage to the trees or the fruit.”

An urban farm on Staten Island and some home gardeners have also reported seeing the lanterflies, both nymphs and adults, on cucumbers, Eshenaur says.

The lanternflies hop from plant to plant as they search for food and wind can also aid their spread, Eshenaur says. “There is some speculation that they may been blown onto Staten Island from New Jersey.”

“They are not strong fliers,” he says. “They can flap their wings and maybe make it four miles in a year.”

They can also hitch a ride on vehicles, and the egg masses may be moved and spread unknowingly.

What to do if you see one

“We definitely want people to look for the spotted lanternfly and to look for the egg masses” that the adult females lay on smooth hard surfaces in the fall before a hard freeze kills all of the adult lanternflies, Eshenaur says. “They can be laid on anything, from the end of September through November – firewood, lawn chairs, seat cushions, even a hat left outside.”

There are an average of 40 individual eggs in these masses, so scraping away the egg masses and “killing them can have an effect on the new local population,” he says. Typically, the taupe- or putty-colored egg masses are “2 inches long, normally situated vertically, and 1 inch wide that weathers to a grayish color.”

If possible, residents should try to catch and kill the lanternflies, but “they are quick, even the nymphs,” Eshenaur says. “It might sound funny, but people are doing well with battery-powered portable vacuums. That’s an option for home gardeners that’s pesticide free.”

(Just leave the collected bugs in the vacuum in the sun for a day and that should kill them.)

“We’re not talking about eradicating them,” but these efforts “and just stomping on them can make a reduction in local populations,” Eshenaur says.

Circle and sticky traps that can be put around tree trunks are also available online, he says. But be sure that the traps are encircled with some sort of wire mesh to avoid trapping birds.

How you can help

You can help the NYS Department of Agriculture and Markets by reporting spotted lanternfly (SLF) sightings. Follow these steps:

• Take pictures of the insect, egg masses or infestations.

• If possible, collect the insect. Place it in a bag and freeze, or in a jar with rubbing alcohol or hand sanitizer.

• Note the location (street address and zip code, intersecting roads, landmarks, or GPS coordinates).

• Send the information to NYS. Dept. Agriculture and Markets in one of two ways. This website ReportSLF.com takes you to the NYS reporting page, or email pictures and location to spottedlanternfly@agriculture.ny.gov.

• New York City residents no longer need to report sightings.

• After you have reported SLF in your area and collected a sample, you should kill any additional SLF you see by stepping on it or crushing it.

Want more information?

Cornell's Integrated Pest Management Program: nysipm.cornell.edu/environment/invasive-species

New York State Department of Agriculture and Markets: agriculture.ny.gov/spottedlanternfly

Find a map of infestation reports across the country: nysipm.cornell.edu

This article originally appeared on Rockland/Westchester Journal News: Spotted lanternfly is now in the Hudson Valley; where it's been seen