Agricultural pest is targeted in Santa Clarita Valley

State agricultural officials have declared war on the Oriental fruit fly in the Santa Clarita Valley after five flies were trapped there over two days last month.

The action is the first for the Santa Clarita area but is one of several in Southern California since the invasive flies turned up in Pasadena in 2010.

Slightly larger than a housefly and marked by a black “T” on its yellow abdomen, the fly is typically found in Hawaii and Micronesia. It poses a threat to scores of fruits and vegetables here, including dates, avocados, tomatoes and peppers. Females lay eggs in fruit and the larvae then tunnel through the flesh.

The flies could cause as much as $176 million in crop damage if they become established in California, officials say.

“If this pest spreads, it’s going to mean more food left unfit for consumption,” said Ken Pellman, a spokesman for the Los Angeles County agricultural commissioner. “It’s very serious to us.”

Pasadena’s 2010 outbreak was quashed after officials quarantined a huge area and barred backyard gardeners from moving plants from their properties and required them to eat their produce at home. Subsequent infestations in Baldwin Park, North Hollywood and elsewhere also were successfully stopped by eradication operations.

To combat the flies in the Santa Clarita Valley, where they threaten citrus and other crops, workers from the California Department of Food and Agriculture have squirted spots of pesticide-laden bait about eight to 10 feet up on the trunks of trees along streets, Pellman said. The male of the species consumes the bait and dies. About 600 bait stations were placed across the 16-square-mile area where the flies were found. The process will be repeated at intervals over 12 weeks.

Officials said the technique exposes people to “negligible” pesticide residue. The treatment is “non-intrusive,” Pellman said. “Most people won’t even notice.”

Long-standing restrictions on bringing in fruit, flowers and plants from out of state and abroad remain in place in California in order to prevent “these hitchhikers,” Pellman said. “If we prevent this from happening in the first place, it saves a lot of money and use of pesticides and protects California’s economy.”

The flies are among a dozen pests featured on California’s “Most Wanted Insect Pests” list, including Mediterranean fruit flies and Japanese beetles. To report incidents, consult the Los Angeles County Agricultural Commissioner/Weights and Measures website or call (626) 575-5471.

ann.simmons@latimes.com