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Fairfax launches plan to combat invasive spotted lanternfly in parks

Experts are focusing on getting rid of the insect’s favored host, the tree of heaven

The spotted lanternfly, an invasive insect from Asia, is spreading in the D.C. region. (Emily Wallis for The Washington Post)
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Barely six months after the invasive spotted lanternfly had been found in Loudoun County, it’s now made its way into neighboring Fairfax County and been found at 11 spots, including on private property and at public parks.

Scientists in Fairfax have launched a four-year, $200,000 effort to try to mitigate the spread and damage of the lanternfly at two county parks — 1,200-acre Laurel Hill in Lorton and 10-acre Blake Lane in Oakton.

For humans, the lanternfly isn’t dangerous. It doesn’t bite and it’s not poisonous. It’s just messy, excreting a sugary liquid called honeydew that leaves a sticky residue when it lands on trees, plants, cars and patios.

“They’re mostly a gross mess,” said Rachel Habig-Myers, an urban forester for Fairfax County’s Department of Public Works and Environmental Services.

The honeydew is harmful to grapevines, bees and fruit crops because it triggers the growth of a black mold that stops sunlight from getting to plant leaves, hindering photosynthesis, scientists said. Grapes polluted by honeydew typically can’t be used for making wine. And bees that feed on honeydew make a dark honey that has a smoky, earthy flavor that doesn’t taste good.

The spotted lanternfly can ruin crops. It’s invading Loudoun County.

The effort to tackle the lanternfly in Fairfax is funded by the county, the local park authority and a $20,000 grant from the Dominion Energy Charitable Foundation.

Experts are focusing on getting rid of the insect’s favored host, the tree of heaven, by cutting it down and using herbicide to kill it.

Because the lanternfly can travel three to four miles, an infestation can spread far, experts said.

Habig-Myers said that while there’s not a large lanternfly infestation in Fairfax yet, “it starts with one and then the population builds … it can become a very large population of insects at once.”

Native to Asia, the spotted lanternfly was found in Berks County in Pennsylvania in 2014, probably having hopped aboard a shipment of stone to reach its new home. It has since spread along the Northeast, Midwest and Mid-Atlantic region, including Delaware and Maryland.

While the lanternfly prefers the tree of heaven, it’s also known to feed on more than 70 types of trees and plants, including willows and maples.

Yale honors Black girl who was reported to police as she sprayed lanternflies

They reproduce fast. A female typically lays eggs from September through December on tree bark, rocks or lawn furniture. She lays up to two egg masses at a time, which look like patches of dried mud, and each mass can hold about 30 to 50 eggs.

When they hatch, the tiny lanternflies are black and white. By midsummer, they typically develop the spotted wings on their backs, and they tend to die off by Thanksgiving or when the first hard freeze hits.

There are few lanternfly predators other than praying mantises, which can’t keep the invasive insects in check if the population gets too big.

Fairfax park officials said they want to keep the lanternfly population from growing because too many insects could dissuade the public from coming to recreation areas, playgrounds, pools and picnic shelters. The loss of park entry fees would be an economic blow, according to John Burke, the natural resources branch manager for the Fairfax County Park Authority.

“For the last half of the summer, it could be rainy sticky honeydew in isolated situations,” Habig-Myers said.

The invasive spotted lantern fly is spreading across the Mid-Atlantic

County park officials said they chose Laurel Hill and Blake Lane because they have a high density of trees of heaven, so they hope that by eliminating the insects’ favored host it will decrease the insects presence, too. Some of the trees they’re taking down will be replaced with oaks, dogwoods and other trees, park officials said.

Still, experts warn that the public should get used to seeing spotted lanternflies.

“There’s promising work being done on a fungus that may kill them all,” Habig-Myers said, “but we anticipate the mess of them being here for a few years and don’t expect to them to go away forever.”

If someone sees a lanternfly in Fairfax, they can report it by sending an email to or calling 703-324-5304. Visit the county’s website for more details.