Battle underway to stop invasive insect from spreading

Virginia Tech working to raise awareness, monitor movement of the spotted lanternfly

A recently arrived invasive insect could be making its way to Rappahannock, and if it does things could get sticky.

Reports of the spotted lanternfly, a sap-sucking bug that secretes a viscous residue, were confirmed in nearby Winchester in January, and a team of researchers from Virginia Tech has been working to track its movements.

Some of that job has fallen to Doug Pfeiffer, an entomologist at Virginia Tech who shared information about the insect during a cooperative extension meeting in late June at Rockmills Vineyard.

An adult spotted lanternfly looks like a colorful moth. When it opens its wings, yellow and red patches are exposed. By Doug Pfeiffer

He says the spotted lanternfly has proven both an agricultural and domestic pest in Pennsylvania, where it was first detected, because it exists in such high numbers. Thousands have coated shade trees in yards in the state and raised concerns about the impact it could have on Pennsylvania’s fruit and timber industries.

“SFL is a major threat,” said Pfeiffer, referring to the insect by its initials.

He doesn’t expect to see much economic impact in Virginia this year, since it has only been detected in small numbers. But once its population grows, it could seriously affect a range of crops. “The most critical that we can tell right now are grapes, stone fruits, hops,” said Pfeiffer. “But apples and vegetables are also at risk.”

A hitch-hiker from around the globe

The spotted lanternfly is native to China, India and Vietnam, with infestations in Korea. It is likely to have arrived in the U.S. from China on shipping materials, states a fact sheet on the insect from the extension office, which calls it “highly invasive” and capable of spreading rapidly when introduced to new areas.

It was first detected in eastern Pennsylvania in September 2014 — the first time it was spotted outside Asia — and spread dramatically in the following years.

Two immature spotted lanternflies at different stages of growth. By Doug Pfeiffer

According to the U.S. Department of Agriculture, the affected area expanded from 174 square miles in fiscal year 2016 to approximately 3,000 square miles by the end of 2017.

By the start of this year, Pennsylvania had issued a quarantine for 13 counties in the state’s southern region. Sighting have also been reported in New York and Delaware in addition to Virginia.

In response to rising concerns, the USDA announced in February that it was committing $17.5 million in emergency funding to expand surveillance and control programs to help stop the insect from spreading in Pennsylvania.

The agency said its Animal and Plant Health Inspection Service is planning to conduct surveys and possibly control measures in Delaware, Maryland, New Jersey, New York and Virginia.

Think the stinkbug is bad?

A line of immature spotted lanternflies walking up the stem of a smooth Sumac tree in late June. Immature spotted lanternflies are wingless and black and have white spots that develop to red patches. By Doug Pfeiffer

The spotted lanternfly feeds on more than 70 types of plants, sucking sap from stems and leaves that can cause the tree to wither and eventually contribute to its death. It also secretes a sticky residue called honeydew that can lead to the growth of sooty mold fungus and severely harm the health of a plant.

It puts out honeydew on decks, houses, toys, vehicles, as well so everything just becomes shiny and sticky, Pfeiffer said. “Parents don’t want to send their kids out.”

What researchers and authorities are most concerned with now is stopping its spread.

Females can lay dozens of eggs and will do so on any vertical, smooth surface, including trains and vehicles that could carry them long distances. The insect’s preferred host, the Tree of Heaven, is found in much of the U.S., often growing along roadways.

It’s not known how the spotted lanternfly got to Virginia, but Pfeiffer said he and others are keeping a close watch on a rail line that runs by the sightings and have noticed insects on idle train cars. If it were August or September, when they’re laying eggs, the train cars could transport those eggs hundreds of miles.

“That’s a risk we’re really worried about,” he said.

Several general predators, such as spiders, wheel bugs and praying mantis, can attack the spotted lanternfly but are unlikely to put much of a dent in a major infestation, Pfeiffer said. A wasp in China could prove a hopeful prospect but would require several years of research and regulatory approval.

Farmers can try to control it by removing the Tree of Heaven or spraying for it if it gets on crops, he noted.

It hasn’t shown up here as a crop pest yet, but growers in Pennsylvania were saying it was low in numbers when they first found it and then it really exploded, said Pfeiffer. He expects that would be the pattern Virginia would see too.

The best thing farmers can do now is be aware of its appearance and importance and notify Virginia Tech’s cooperative extension office by email or by uploading a photograph with the location to They can also notify their county cooperative extension agent.

What to look for:

Affected trees will develop weeping wounds that leave a grey or black trail along the trunk. In the late fall egg masses will start to appear that have a grey mud-like covering that becomes dry and cracked, according to the Pennsylvania Department of Agriculture. The honeydew attracts other insects such as ants and wasps, providing another indicator of its presence. Adult are best spotted at dusk or night walking on tree trunks, stems and leaf litter at the base of trees.

Pennsylvania’s Department of Agriculture offers several options for combating them:

For more information about the risk, signs and symptoms, visit the USDA’s Hungry Pests site:

Sara Schonhardt
About Sara Schonhardt 20 Articles
Sara Schonhardt is the summer fellow for Foothills Forum. A former staff reporter for the Wall Street Journal in Indonesia, Sara reported from around Southeast Asia for more than 10 years for the International Herald Tribune, Christian Science Monitor and Voice of America, among others. Her most recent reporting has focused on rural communities in southern Ohio.