Anthony Vietri learned a lot about the spotted lanternfly during the three seasons he dealt with the invasive pest in his Pennsylvania vineyards. “It’s an infuriating but fascinating insect,” explains the owner and winemaker of Va La Vineyards. “As adults, they have a rather annoying habit of jumping on things in passing – cars, animals and, unfortunately, your face.”
The spotted lantern is a biting and sucking insect that feeds on plant sap, making it a major threat to fruit crops and trees. Black with white spots, they develop bright red hindwings as they age and are fairly easy to identify. While the insect’s behaviors are better understood now than when they were first discovered in the United States, wineries are still figuring out the best approach to protecting their vines from invasive species.
Since spotted lantern flies were first detected in Berks County, Pennsylvania in September 2014, infestations have been reported in 11 states, according to USDA, including New Jersey, New York, Delaware, Maryland, Virginia, Connecticut, Massachusetts, Indiana, Ohio and West Virginia. Vineyards in these states suffered vine damage, as well as yield and revenue loss, as a result of these infestations.
“They can be extremely irritating to outside visitors to tasting rooms,” says Vietri. He points out how annoying jumping insects are at events like weddings. “And much worse, they are sap eaters that will destroy the vines if they infest in large numbers.”
Native to Asia, the spotted lantern is primarily known to feed on the tree of heaven, but has a wide host range, including apples, cherries, hops, plums, and grapes. They produce one generation a year, says Michela Centinari, an associate professor of viticulture at Pennsylvania State University, who is conduct research on the Mottled Lantern and public awareness efforts to control the pest.
Adult Mottled Lanterns lay their eggs in the fall. The egg masses, which can contain 30 to 50 eggs each, can survive cold winter temperatures, even after most adults have frozen to death. Depending on a region’s spring warmth, they emerge as nymphs in early or late May. That’s when, Centinari says, populations are easiest to control.
“Typically, that’s when growers have to spray for Japanese beetles and many other pests, and can kill the lanterns because they don’t fly, they just jump,” she says. “The problem is when they become adults, usually in July.”
At this point, they no longer have any food sources in the wooded areas and begin to move to the outer rows of neighboring vineyards in early August. They settle in the canopy and like to feed off the stem, sucking up sugar and nutrients that would otherwise have to go to the grapes at a pivotal time.
“Fortunately, they are very sensitive to most insecticides, which at this point is our only line of defense,” says Mike Beneduce, Vineyard Manager and Winemaker at Bénéduce vineyards in Pittstown, New Jersey. He saw the first wave of Mottled Lanterns hit his vineyard in 2019. Unfortunately, when the adult insects are most active, in August and September, is also when the harvest starts, making it difficult to spray pesticides. to fight them.
The best way to kill adult Mottled Lanterns is to crush or stomp on them, which isn’t difficult. Although they are good at jumping, they are not very good at flying. But it is labor intensive at an already labor intensive part of the year for winemaking.
“As far as eradication goes, well, we think you can’t really,” Vietri says. “We are dedicated to biological controls, and none of these are working so far that we can see.” But even if vintners completely eradicate the spotted lanternfly on their own property, it’s only a short time before the pest returns from other surrounding properties.
Some wineries are testing other approaches to managing spotted lanternfly populations. Unionville Vineyards in Ringoes, New Jersey, first noticed the bugs in their vineyards at the end of the 2019 season and have since introduced insecticidal spray to their regular post-harvest fungicide application, an added cost to their operations.
This spring, the winery will introduce chickens to the vines. “We’re hoping they’ll devour the pests in the nymph and larval stage before we have to fight them as adults,” says John Cifelli, the vineyard’s general manager.
In Pennsylvania, Vietri scavenges praying mantis nests from the vines each winter when pruning, then later reintroduces them to the vines for insect control. “Although we have a very nice population of praying mantises and they love to eat spotted lanterns, they can’t make any noticeable dent in the huge populations,” he says.
Beneduce remains hopeful. “I may be overly optimistic, but my hunch is that, like invasive species that came before them, like Japanese beetles and stink bugs, they will eventually adapt to their new environment,” he says.
For wine regions that have yet to experience spotted lanternfly infestations, prevention is key. Although no live populations of Spotted Lanterns have yet been found in California, the state Department of Food and Agriculture is already training county agricultural staff, as well as inspection station personnel. borders and points of entry, to identify and control the pest.
In the meantime, Vietri and other East Coast winemakers are learning to live with them. “We know they’re coming. We can’t completely stop them,” he says. “If we can keep the population under control and our vines happy, then we’ll survive to grow again.”