How California eradicated an invasive grapevine moth

The European grapevine moth, first spotted in California in 2009, has been declared eradicated on US soil. It took seven years' worth of effort and over 65 million dollars of federal funding to defeat the insect.

Since 2009, California farmers and agricultural officials of California have been at war with the European grapevine moth. The invasive species threatened the region's massive wine and grape industry and threatened to throw off the balance of the local ecosystem.

But now, after seven years, the war is over. The moth has been declared eradicated from the United States.

The European grapevine moth, Lobesia botrana, is native to southern Europe. The insect's larvae feed on grape bud clusters as well as the developing fruit, exposing them to damaging fungi and other pests.

The appearance of the moths came as a surprise. In October of 2009, multiple moths and larvae were discovered in a Napa County vineyard, according to a 2010 press release from the County of Sonoma Agricultural Commissioner's office. In response, several measures were put in place to combat the invasive species. The USDA and CDFA quickly quarantined the affected vineyards and began setting up traps to keep track of the moth population.

It is still unknown how the insects got to the US, but they quickly spread to other counties in California, and their numbers quickly climbed to a peak in 2010, when more than 100,000 moths were detected through traps. By that time, 52,170 acres of California vineyards had been put under quarantine, according to The Press Democrat.

The explosion in the population of moths is common among invasive species. In their native habitats, there are natural checks and balances in the population of species. When they are introduced to somewhere new, a lack of natural predators and reduced competition for food can cause the species to grow unchecked and cause substantial damage to the ecosystem.

This was of particular concern for the grapevine moths in California, whose grapevines power a multibillion dollar wine industry, according to the California Wines website. The potential economic impact of a rapidly growing pest prompted cooperation from the grape industry, environmentalists, as well as local, state, and government officials to come together to eradicate the moth.

A coordinated campaign to keep growers informed was put in motion and laws concerned with preventing contamination of non-quarantined vineyards were put in place. Congress approved 65 million dollars in federal funding for the elimination of the pest, according to a recent press release.

Seven years and 65 million dollars later, US Department of Agriculture’s Animal and Plant Health Inspection Service, or APHIS, has declared the eradication of the European grapevine month a success.

“This is a very significant accomplishment,” said Tony Linegar, the agricultural commissioner for Sonoma County, California, to The Press Democrat. “Any time you propose to eradicate an insect from a continent, that is a very lofty goal.”

Most invasive-species-eradication efforts do not go nearly as well. According to the US Fish and Wildlife Service, there are about 4,300 species in the United States that have been considered invasive. Once entrenched, they push out native species by preying on them or out-competing them. As a result, they are very hard to eradicate without doing further damage.

Other invasive species in the US include the brown marmorated stink bugs and Asian carp. These species have resisted all efforts of eradication and continue to increase their territory, according to the National Wildlife Federation's website.

Usually the best one can hope for is that an invasive species will never be brought to a nonnative habitat in the first place. But rising temperatures across the globe are prompting many species to leave home and set up life elsewhere. According to the National Wildlife Federation, approximately 42 percent of all threatened or endangered animal species are primarily threatened by the invasion of other species into their habitats.

The European grapevine moth's eradication is an unusual victory in the battle against invasive species. Early recognition of the problem and cooperation was the key to eliminating the moth before it was too late. 

In addition to quarantines and pesticides, a lab-created pheromone that rendered male moths unable to find mates, helped defeat the pest.

“Left unchecked and untreated, this infestation would have grown and grown,” Dave Whitmer, former Napa county agriculture commissioner, told the Press Democrat. “I would venture we wouldn’t have had the success without the use of the pheromone.” 

Many locals are doubtful that the moth has indeed been eradicated, according to Capital Berg. But the last official sighting of the moth was in 2014, which has given APHIS enough confidence to give the all-clear.

While the moth is finally out of the US, the battle against the invasive species rages on in Chile, where it was first detected in 2008. 

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to

QR Code to How California eradicated an invasive grapevine moth
Read this article in
QR Code to Subscription page
Start your subscription today