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Medflies found in county for first time since 2001

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Times Staff Writer

SACRAMENTO -- One of the Golden State’s most notorious invasive pests -- the crop-devouring Medfly -- has reappeared in Los Angeles County for the first time in half a dozen years, state officials announced Thursday.

Authorities said they expected to soon establish a quarantine zone on the Palos Verdes Peninsula -- the site of the discovery -- and begin stepped-up treatment to kill a pest long feared as among the most worrisome threats to the state’s agricultural economy.

A single Mediterranean fruit fly was discovered Wednesday in a pineapple-guava tree in Rancho Palos Verdes, while three of the flies were caught the same day in a trap dangling in a backyard orange tree in the adjacent community of Rolling Hills, said Steve Lyle, a spokesman for the California Department of Food and Agriculture.

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Officials soon will begin dispatching notices to residents in the affected area, urging them to take steps to stem the infestation, including refraining from removing fruits and vegetables until the infestation is eliminated. That process typically can take nine months to a year.

Ground crews today are set to begin spot-spraying an organic pesticide on bushes and fruit trees within a 200-meter radius -- about one-eighth of a mile -- from where the Medflies were trapped, Lyle said. The main insect-killing ingredient is a naturally occurring extract from bacteria.

On Saturday, a twin-engine plane will begin the aerial release of sterile male Medflies at a rate of 250,000 per square mile over the infestation area.

For the last decade, the Los Angeles Basin has been part of a state and federal project that has spread sterile Medflies weekly across the region to keep the pest in check. But the turf surrounding the new discoveries will see a fourfold increase in the number of sterile flies being released, Lyle said.

“We’re very good at eradicating these infestations,” he said. “We’re batting a thousand. It’s a much different approach than in the past.”

During the early 1980s, then-Gov. Jerry Brown endured harsh public criticism over the aerial spraying of the chemical pesticide Malathion over parts of the Bay Area to eradicate the state’s first Medfly infestation.

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Los Angeles County battled the pest in the late 1980s and early ‘90s, becoming something of a Medfly hot spot.

But the weekly release of sterile flies put a dent in the problem.

Before the start of that effort in 1996, the state was averaging 7.5 infestations a year. In the decade since, only seven infestations have been recorded in California.

Three of those, however, have occurred in just the last month and in widely divergent parts of the state. Aside from the finds in the Southland this week, Medfly infestations have hit San Jose and the Sacramento Valley farm community of Dixon.

The discovery in Dixon, in the heart of the state’s agricultural breadbasket, was the most troublesome and marked the first time the fly has been traced to the Central Valley since the early 1980s.

Medflies are known to feast on upward of 260 crops, making them a disquieting potential threat. This week’s Medfly discovery is the first in Los Angeles County since a 2001 infestation in Hyde Park. The winged invaders were successfully eradicated with ground spraying and the release of sterile Medflies.

eric.bailey@latimes.com

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