Uninvited pest

There's an unwelcome visitor in the Sonoma Valley.

Meet the light brown apple moth, a voracious pest that eats almost any crop or ornamental plant -- grapes, citrus, roses, mums, even oaks and redwoods.

Native to Australia, its presence was first confirmed in California last year. Infestations have since been detected as far south as Santa Barbara County and as far north as Marin and Solano counties.

The U.S. Department of Agriculture says a general infestation could cause as much as $640 million a year in crop damage. The state and federal governments have undertaken a $75 million eradication plan.

Sonoma is experiencing the first stage of that program following the discovery of an apple moth in late April. It was the second found this year, signaling an infestation rather than a lone hitchhiker being transported into the area.

Extensive inspections are planned within a 15-square-mile quarantine zone created last week that encompasses 2,500 acres of vineyards and a half-dozen nurseries.

Residents are prohibited from taking homegrown plants, flowers, fruits and vegetables outside the affected area.

The next step is likely to be placement of special twist ties infused with a synthetic pheromone that disrupts moth mating.

State officials said the quarantine will remain until the area is free of the pest for three life cycles, which are about seven weeks each.

At this time, there are no plans for aerial spraying of the pheromone.

After a round of spraying in Monterey and Santa Cruz counties last year, hundreds of people complained of feeling sick. A judge ultimately ordered a halt to spraying pending a study of the effects on people and the environment.

But a team of scientists assembled by the U.S. Department of Agriculture concluded in a report released Monday that the state can't get rid of the moths with the twist ties alone, and dismissed concerns about harmful effects from aerial spraying.

If the twist ties don't do the job and spraying is proposed in Sonoma, there will be a conflict between two sets of deeply held views: agriculture as a cornerstone of the area's economy and lifestyle, and concerns about the potential side-effects of chemicals.

Let's hope our unwelcome visitor hasn't put down roots so that battle can be avoided.