The spotted lanternfly continues to move outward from its Southeast Pennsylvania epicenter, threatening grapevines and complicating vineyard management in new regions.
The invasive planthopper migrated south to Virginia several years ago and is starting to infest the state’s vineyard regions in large numbers. There are more than 4,000 acres of wine grapes in Virginia, most clustered in the northern and central parts of the state. To manage the pest, growers and researchers are building on lessons learned in Pennsylvania, as well as their own experience.
“It’s not a hard insect to kill, but you have to kill it repeatedly because it immigrates from surrounding woods,” said Virginia Tech entomology professor Doug Pfeiffer.
High populations of the sap-sucking planthopper (an insect family that is distinct from but related to leafhoppers and treehoppers) can damage or kill grapevines over time. Broad-spectrum insecticides, especially pyrethroids and neonicotinoids, are the best-known way to combat SLF, but using them comes at a cost. They can also hurt beneficial insects, so outbreaks of secondary pests after spraying with those products are common, Pfeiffer said.
As SLF continues to spread, researchers and growers will have to adapt management guidelines to fit regional conditions. In Virginia, for example, adult spotted lanternflies become active as early as late July, while the state grows a lot of late-season red grapes that aren’t picked until October. That’s a long feeding window to manage, said Virginia Tech viticulture extension specialist Drew Harner.
Harner shared some SLF management pointers: Remove tree of heaven, SLF’s preferred host. Scout for SLF adults, which do most of the damage. The pest tends to cluster at vineyard borders, so spraying the perimeter can be as effective as spraying the entire block. But at a certain point, usually in late September, SLF becomes more mobile and can build up large populations in vineyard interiors. Scout to confirm their locations and adjust your sprays accordingly, he said.
In Northern Virginia, the hardest-hit region so far, SLF damage has varied. Jason Murray, co-owner of Arterra Wines, said his vineyard hasn’t had a high level of infestation, but for other vineyards it’s been “biblical.”
Murray first saw SLF on his vines in 2023. The numbers weren’t huge, but the timing wasn’t great. His vineyard began the transition to organic certification in August 2024 and is scheduled to complete it by August 2027. His last conventional spray against SLF, a pyrethroid, worked really well, he said, but since then his only spray option has been the organic-approved PyGanic (pyrethrins), which kills SLF on contact but has no residual efficacy.
Murray removed most tree of heaven from his property but kept a few trees on the perimeter to draw SLF away from his winery. He doesn’t want to see the insects bouncing off customers, he said.
Beth Sastre, commercial horticulturist with Virginia Cooperative Extension, Loudoun County, said she has found “humongous amounts” of egg masses under grape cordons and angled end posts in vineyards, where the pest seeks protection from extreme weather. She said bats, birds and spiders have been observed preying on SLF, but not in amounts needed for adequate control.
SLF is also widespread in Central Virginia vineyards, including her own, said winemaker AJ Greely of Hark Vineyards.
The vineyard team hasn’t seen signs of vines dying, but fruit quality has been affected. They had to throw away juice from a heavily infested part of the vineyard because it “smelled like tomato soup,” said Greely, who is also president of the Virginia Vineyards Association.
Based on Hark Vineyards’ experience, spraying a neonicotinoid right after harvest can control SLF without hurting beneficial insects. They noticed birds in their vineyard are starting to prey on SLF, which is good but also causes peck damage on grapes. They plan to net the most heavily pecked areas, she said.
Greely said the pests also hop around their wine-tasting areas, but, fortunately, they don’t seem to scare off the clientele.
“Our customers are happy to step on spotted lanternfly for us,” she said with a laugh.
At Loving Cup Vineyard and Winery, which is certified organic, owner Karl Hambsch had to prepare for SLF ahead of time. To bulk up his wine inventory, he spent a couple of years harvesting more grapes and making more wine than he needed. When SLF arrived in significant numbers, he started reducing crop loads. His thinking was that his vines could put less energy into fruit production and more energy into resisting SLF damage, he said.
To preserve beneficial insects, Hambsch doesn’t want to spray insecticides, even organic products. His strategy with SLF, as with all invasive pests, is to weather the huge spike of initial populations until, hopefully, “nature absorbs the invasive,” he said. Then, it’s no longer an existential threat.
Hambsch said it’s a risky, perhaps even naive, strategy, but his vineyard has withstood waves of invasive insects before and remains certified organic. He has enough wine to keep his tasting room open for two or maybe three years. But if the SLF surge lasts longer than that of the brown marmorated stink bug and other previous invasives, he’s going to end up with a supply problem.
“Spotted lanternfly might be the exception,” Hambsch said. “But I’m not ready to throw out our whole system unless we have to.” •
