Scouting the Spotted Lanternfly to Halt Vineyard Invasions
Spotted Lanternflies attack a grapevine. (Photo by Lee Carper, USDA)
Agricultural Research Service (ARS) scientists are tackling the wave of concern spreading through American vineyards. The Spotted Lanternfly, an invasive insect native to Asia, was first discovered in the United States as recently as 2014. The pest has spread rapidly to more than a dozen states and may seriously threaten the grape grower and wine industries, which combined contribute an estimated $300 billion to the U.S. economy.
The Spotted Lanternfly has quickly become a significant concern for American grape growers, as it feeds on the plant sap, causing stress to grapevines, and over time, reducing growth and fruit yields.
ARS researchers are scouting Spotted Lanternfly’s growing presence in vineyards, seeing it move from Pennsylvania and Virginia to Maryland, New Jersey, and West Virginia. Tracy Leskey, ARS research leader and entomologist at the Appalachian Fruit Research Station, Innovative Fruit Production, Improvement, and Protection Unit in Kearneysville, WV, is working to determine the range of its infestations.
“Our study at Kearneysville will help us look at the impact of their feeding on wine and table grape varieties over time, and if they can be managed with a visual scouting-based threshold,” said Leskey.
Spotted Lanternfly nymphs infestation of grape leaves. (Photo by Torri Hancock, USDA).
Through ARS’ Area-Wide Pest Management Program, Leskey and her research team have set up monitoring traps within some of the vineyard’s periphery to capture Spotted Lanternflies.
“This will give us a sense of the population in the unmanaged wild host habitat that could invade vineyards,” Leskey said. “In the vineyard itself, we conduct visual counts of all adults and nymphs that we find on select rows and sample sites to give us a sense of the pest pressure.”
Leskey added that twice a year, the researchers also conduct long-range scouting to “look for the presence of any Verticillium nonalfalfae (a soilborne fungus) that can harm Tree of Heaven, which is a common and highly favored host plant for the spottled lanternfly. Tree of Heaven is often found growing on the border of vineyards and orchards. If Tree of Heaven is not available for Spotted Lanternfly, this could help reduce the numbers invading vineyards, reducing their impacts.
Leskey and her research partners are also looking at ants to help learn more about the Spotted Lanternfly’s spread.
This project is led by ARS colleagues at Virginia Tech. As part of the Area-Wide project.
“We are sampling foraging ants to determine if they are picking up the presence of Spotted Lanternfly, such as DNA in their honeydew (or the liquid waste secreted by certain sap-feeding insects), which the ants eat,” Leskey explained. “This will help us determine how far away from the vineyards infestations exist.”
In addition, ARS researchers and their university partners are characterizing the wooded areas around the vineyards, using typical survey methods on the ground and drones.
“Our colleagues at Penn State did most of the insecticide testing against Spotted Lanternfly initially, so we know what is effective,” Leskey said. “We are determining when to treat for them – rather than just going out and treating every week, or even twice a week (as some growers have). Our team goes into the vineyard and counts the numbers of Spotted Lanternflies present on the vines. If they reflect relative densities, or numbers that could be harmful to the vines, only then do we apply insecticides. In other words, we only spray when we need to do so.”
ARS researchers study the effect of Spotted Lanternfly on these Cabernet Franc wine grapes that were planted in 2020. (Photo by Laura Nixon, ARS).
All these efforts are part of ARS’s goal to develop new methods for treating Spotted Lanternflies and help growers combat this invasive pest from causing excessive crop damage.
“We would also like to work with some organically approved materials like Surround (kaolin clay) to determine if it can behaviorally deter Spotted Lanternfly,” Leskey said. “Insects do not like to walk on this material as it sticks to them, and it can block their spiracles and mouthparts.
“Once we have completed the first study,” she continued, “we want to find out if we can get away with only treating the borders of vineyards, rather than the entire vineyard. This could reduce the impact on pollinators and more natural enemies of the Spotted Lanternfly.” – Tami Terella-Faram, ARS Office of Communications
For more information: https://www.ars.usda.gov/oc/dof/tree-of-heaven-serves-as-devilish-host-to-spotted-lanternfly/