Vintners Recruit Lacewings to Destroy Vineyard Pests

Lacewings, also known as aphid lions for their predatory nature in the vineyard, have become a key ally for growers across the world.

By Kathleen Willcox 

The move toward more eco-friendly farming methods is almost universal in wine country. Whether or not growers are certified organic, biodynamic or have opted for another sustainably-minded form of certification, these days it would be tough to find any content with nuking their vineyards with Round-Up. Instead, growers see increasingly eco-friendly viticulture as simply a smart way to do business.

“We’ve been following the LODI Rules for sustainable winegrowing for more than a decade, but we’ve never officially certified our vineyards,” says Kade Casciato, vineyard manager at Ciel du Cheval in Washington state’s Red Mountain AVA. Ciel du Cheval has a 120-acre estate, with 100 acres under vine. “We see using fewer chemicals and friendlier chemicals as the least we can do as good stewards of the earth — and as good neighbors. We will soon certify under the new Washington Sustainability label, simply because more and more wineries want to ensure grapes are grown responsibly.”

Without being able to turn to insect- and disease- (and water-, soil- and all forms of life)-destroying sprays, growers like Casciato are seeking out less conventional methods of targeted pest-control. 

Lacewings, also known as aphid lions for their predatory nature in the vineyard, have become a key ally for growers across the world. 

Lacewings Ferociously Target Grape Pests

Lacewings target mealybugs, aphids, thrips, leafhoppers and spidermites, says Maya Dalla Valle, winemaker at Dalla Valle Vineyards in Napa, Calif. The estate has 20 acres under vine, and has been organically certified since 2007. 

Dalla Valle says they release lacewings on egg cards around the vineyard and finds that, “despite their short lifespan of just two to three weeks, they will consume up to 250 leafhopper nymphs, or 11,200 spider mites, which I find very impressive!”

Casciato, who uses hundreds of cards — each of which has up to 300 lacewing eggs on them — in the vineyard each year, is equally impressed with the insect’s  ability to destroy mealybugs and mites. 

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“The mites that the lacewings target feed on leaves and, when they’re uncontrolled, can lower the vine’s ability to produce sugar, which severely impacts flavors in the wine,” he explains. “Mealybugs aren’t necessarily a terrible problem in and of themselves, but they are vectors for grapevine viruses. Serious viruses such as leafroll, which impacts the vine’s ability to ripen fruit, especially in August and September when the fruit should be finishing, can be spread by mealybugs getting stuck to farm equipment like shears. They’re then transferred to other vineyards.”

Leafroll can also significantly cut the life of a vineyard block, which can have a serious economic impact for vineyards depending on vines to last 40 or more years, Casciato says. 

Creating a Safe Space for Lacewings 

Growers who’ve been able to reduce, but not necessarily eliminate, their use of organic and synthetic sprays with the help of lacewings and other beneficial insects, have created bug corridors for them to retreat to when they do spray. Others who want to cultivate long-term populations of lacewings also find a biodiverse setting essential to their success. 

Casciato and his team began creating biodiverse lacewing safe zones in the vineyard for when they do spray as soon as they realized what an asset the bugs could be.

“Around the vineyard, we’re planting many native species of flowers and plants so [the lacewings] have a place to go if a spray is necessary,” he explains. 

In the Sicilia DOC, where lacewings are used as predators, growers have also found that maintaining a safe space for them is essential. 

“We maintain natural grass cover-cropping and preserve wild areas on the outskirts of vineyards to protect them,” explains Alessio Planeta, board member of Sicilia DOC and the region’s sustainability program, SOStain. “Biodiversity is a plural concept, not a singular one. Multiple entities must be in balance.”

At the 173-acre Cantina Endrizzi in Italy’s Trentodoc region, where the vineyard team uses multiple species of beneficial native insects, including lacewings, having a biodiverse vineyard space is essential to their ongoing sustainability efforts.

“We’re surrounded by forests and meadows, which offer enough wintering grounds so that we can look forward to helpers from year to year,” says Torben Endrici, a vineyard project developer at Endrizzi. “[Lacewings] do a great job eliminating mites and their eggs, various lice, grape thrips and cicadas.”

A Less Labor-Intensive Release

Last year, the team at Two Mountain Winery began experimenting with lacewings. 

Two Mountain is a 150-acre vineyard and farms around 400 acres for others in Washington’s Yakima Valley. “We put out about 20 cards of lacewings per acre across 200 acres,” says Patrick Rawn, head of vineyard operations. “This year, we’re hoping to use drones to deploy the lacewings.”

While they saw good results from the lacewing egg card releases, Rawn says the process was labor-intensive and difficult to track. He believes the drones, which are the brainchild of G.S. Long, and are engineered for this purpose, will be more effective at seeding the vineyard and ensuring a stable population. 

“When you’re using cards, it’s hard to know how many eggs hatched,” he notes. “This way, we’ll be releasing live insects. We’re also hoping that, because they’re native to the region, they’ll over-winter and breed. We hope to benefit from them, year after year, without needing to release them every time. We know that lacewings do a great job of targeting mealybugs, but they’re true generalists — and they are ferocious. We think there’s a great future for them with other grape pests, too.”

Lacewings, growers are quick to point out, are not necessarily a panacea. 

“Using lacewings in the vineyard hasn’t allowed us to completely eliminate sprays, but it has let us use much gentler sprays,” says Casciato. “We depend on sulfur for as long as we can, and if something stronger is warranted, with the help of lacewings, we’re able to use less synthetic versions, which are considered nontoxic by sustainability programs.”

For Todd Krivoshein, owner at Page Cellars in Woodinville, Wash., tools like lacewings are a game-changer, letting him and other growers use fewer and gentler sprays.

“Growing up on a 2,300-acre farm in Saskatchewan, I saw firsthand what chemicals did to my father,” Krivoshein says. “He’d come in after treating the fields and be on the couch moaning, with his skin peeling off for days. There are better, more humane and definitely more sustainable ways to farm. Lacewings may seem like a small thing, but they can make a huge difference in the health of the vineyard, workers and community.”

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Kathleen Willcox

Kathleen Willcox writes about wine, food and culture from her home in Saratoga Springs, N.Y. She is keenly interested in sustainability issues, and the business of making ethical drinks and food. Her work appears regularly in Wine Searcher, Wine Enthusiast, Liquor.com and many other publications. Kathleen also co-authored a book called Hudson Valley Wine: A History of Taste & Terroir, which was published in 2017. Follow her wine explorations on Instagram at @kathleenwillcox