Dog squad, not pesticides, drafted in wine war

A golden retriever named Nexus sniffs around for mealybugs at the Honig Vineyard and Winery in Rutherford, Calif. Watching are vintner Elaine Honig, left, and Bonnie Bergin, president of the Assistance Dog Institute.Eric Risberg / AP
/ Source: The Associated Press

California vintners are employing a four-legged ally in their fight against a new pest menacing state vineyards.

A dog squad, still in pilot stages, is one of a number of strategies being considered to stop the vine mealybug, a little insect with the potential to stir up big trouble in wine country.

Small and secretive, vine mealybugs hide under roots and bark where they’re virtually impossible to see with the human eye. They feed on vines and produce a sugary excretion known as honeydew that encourages the growth of sooty mold, and turns vine and grape cluster into a sticky mess.

Once established, it takes a considerable blast of pesticides to get rid of the bugs, an unpopular resort for an industry that has been moving toward using less chemicals.

“The vine mealybug poses a huge threat to our progress toward both sustainable and organic farming practices,” said Jeff Erwin, deputy agriculture commissioner for Napa County.

Learning process
Officials have been finding some success in using golden retrievers to sniff out the root of the problem in its early stages.

So far, dogs have been taught to identify the female mealybug pheromone and recently made the leap to identifying a piece of infected stock, much trickier since it meant dealing with competing, real-life smells such as mold and wood.

“A third of their brain is their olfactory system. There is no machine that can detect odor anywhere near their capabilities,” says Bonnie Bergin, founder of the Assistance Dog Institute in Santa Rosa, which is conducting training for the dogs.

Growers in Napa and Sonoma counties have donated nearly $30,000 for the first year of training and are discussing raising more funds, said Jennifer Kopp, executive director of the Napa Valley Grape Growers Association.

Heading north
The vine mealybug first showed up in Southern California more than 10 years ago and has been moving north into some prime grape-growing areas.

Other preventive efforts underway include using traps baited with a female pheromone to catch the males, which can determine if an infestation is present. Another approach is to try to control the ants that serve as vine mealybug protecters, fighting off predators to keep the supply of sugary honeydew coming.

Erwin is intrigued by the possibilities, which could result in helping growers find vine mealybugs early enough that removal would be a relatively simple matter of removing a few vines or treating a small area.

“When you have a pest like vine mealybug,” he says, “you look for all the possible ways of mitigating the damage and in our case we would love to see vine mealybug eradicated from Napa County.”