Virginia vineyards confront new challenges amid novel pests 

In the face of pests like the spotted lanternfly, Andrew Harner and Virginia Cooperative Extension are working to find strategies that reduce pesticide use, protect grape quality, and keep Virginia’s wine industry thriving.
By Julie Shlisky 

Virginia’s wine industry is booming, with more than 300 wineries and nearly 4,500 acres of vineyards. But growers face challenges that could slow progress. Consumers want wines made with sustainable farming methods. At the same time, pesticide resistance grows and new pests arrive. 

The spotted lanternfly arrived in Frederick County, Virginia, in 2018. Commercial Horticulturist Beth Sastre, who works for Virginia Cooperative Extension in Loudoun County, followed the pest’s spread in Pennsylvania and knew her community would be impacted.

“Loudoun is home to many of the state’s vineyards and wineries, so we raised awareness among county departments, Master Gardeners, homeowners, and students,” Sastre said.

As the spotted lanternfly spread to Virginia, Andrew Harner began investigating how the state’s vineyards could be protected more sustainably. Harner is an assistant professor of viticulture and Extension specialist at the Alson H. Smith Jr. Agricultural Research and Extension Center. His Hatch-funded research helps growers make informed, cost-effective decisions in the face of emerging pests. Hatch research is managed by the U.S. Department of Agriculture, with aims to improve farming practices, rural life, and consumer welfare.

Harner blends lab and field approaches to understand how fruit and grapevines respond to a changing ecosystem. His recent focus is on how spotted lanternfly infestations affect grape quality and yield.

Alongside fruit and wine chemistry experts, Harner looks at how these pests impact fruit ripening, flavor chemistry, and yield — which all can affect wine profitability. The research aims to suggest a spotted lanternfly “action threshold”: a population level that should trigger growers to take pest control actions to prevent damage and avoid unnecessary insecticide treatments. 

 “Virginia growers reported applying up to five additional insecticide treatments over the 2024 season to combat spotted lanternfly alone,” Harner said. “Until new sustainable management practices can be developed, we can help growers decide if it’s time to use aggressive treatments, and, if they do need to use them, how to minimize use and maximize return.”

Virginia growers work in tough conditions and often have slim profits. Bad weather and pests can lead to big losses. Researchers look for strategies to help vineyards stay profitable and protect the environment.

Harner is part of a team recently awarded a seed grant leveraging funding from the College of Natural Resources and Environment to examine increased management costs and losses following vineyard infestation. Some of his other projects examine new grape varieties that resist disease and rely less on pesticide use. He also identifies ideally paired cover crops, grown under vines to control weeds and improve soil health.

Along with Extension agents, Harner is collecting vine samples from local growers who report vines with red leaves after spotted lanternfly infestation, a symptom of plant stress. Harner’s team is investigating whether red-leaf symptoms can serve as early indicators of cold vulnerability — giving growers a chance to act before long-term damage occurs.

At the same time, systems are in place to share best management practices with Virginia growers affected by the spotted lanternfly. In response to stakeholders needs, Loudoun County Virginia Cooperative Extension along with Visit Loudoun, Loudoun Wineries and Winegrowers Association, and Loudoun Invasive Removal Alliance host an annual “Scrape for the Grape” event.

“Anyone growing commercial grapes can volunteer to learn about spotted lanternfly and help destroy egg masses,” said Sastre, who helps coordinate the event. “It raises awareness of this invasive species while helping our rural economy.”

Virginia’s $3.4 billion wine industry depends on solutions like pest thresholds, disease-resistant grape varieties, and cover crops. Harner’s research aims to cut pesticide use, lower costs, and protect yields as growers face a fast-changing pest and pathogen landscape.

 

To learn more about this story, contact Julie Shlisky at juliesb@vt.edu.