Spreading of White Snails in County Worries Experts

A fourth sighting of the pesky white garden snail in San Diego County has agricultural officials worried that the recent infestation could spiral out of control.

The county’s last encounter with the seemingly harmless creatures ravaged more than 100 La Jolla gardens and commercial nurseries in 1922.

“It’s a real concern . . . there is really no effective way we can put a barrier around the snails and keep them from spreading,” said Bill Routhier, pest control manager for the California Department of Food and Agriculture.

The snail, which was discovered last week in gardens in Encanto and Santee, has found its way to Mission Hills and Lakeside, where residents have reported seeing white snails in their irrigated gardens.

“We suspect that people are moving these things from one place to another either as a food product or just because they are pretty,” Routhier said.

The white garden snails, which are less than one inch long with brown swirls along their shells, were brought to the United States from Italy as a delicacy in the 1800s. Since then they have found their way into residential gardens in San Diego County and citrus and avocado groves in Orange and Imperial counties, causing millions of dollars in damage.

Inspectors have collected almost a dumpster-full of the snails from the Encanto and Santee sightings.

The two recent sightings have significantly added to county agriculture officials’ worries because irrigation provides the snails with the moisture they need for reproduction.

The snails found in Encanto and Santee were in the dormant stage--where officials hoped they would remain until the rainy season.

“The snail’s resting period would buy us enough time to form an eradication strategy,” said Kathleen Thuner of the County Department of Agriculture, Weights and Measures.

The creatures, which lay as many as 200 eggs at a time, reproduce very rapidly. With adequate moisture, the snails could create a new generation every 40 days, Thuner said.

“On this kind of reproduction schedule we could triple the snail population in Lakeside and Mission Hills by the end of the year,” Routhier said.

In enormous numbers, the snails can work their way through a residential garden in less than 24 hours, leaving nothing but stems and dirt, Routhier said.

Agricultural officials expect to use a combination of chemical spray, poison bait and mechanical threshers to remove the pests.

Federal inspectors will visit the county next week to determine the extent of the infestation. County officials plan to continue hand-picking the snails until federal inspectors have completely inspected the area and adopted an eradication strategy.