State agricultural officials have begun the second of four treatments in the north-central portion of the San Fernando Valley to eradicate Los Angeles County's first Oriental fruit fly infestation of the season.
The county uses a "male annihilation treatment" to combat the flies, said Bob Donley, deputy director of the Environmental Protection Bureau of the county Agricultural Commissioner's Department. The spraying is done from trucks.
Donley said a half-dollar-size spot, or "base station," is sprayed onto utility poles and tree trunks 8 feet above the ground. The spot contains a combination of methyl eugenol--which mimics the scent of the female Oriental fruit fly--and a pesticide that then kills the duped males.
The area being treated is approximately 10 square miles, bordered by Glenoaks Boulevard, La Tuna Canyon Road and Tuxford Street on the north, Laurel Canyon Boulevard on the west, Victory Boulevard on the south and Buena Vista Street on the east.
Oriental fruit flies are a seasonal problem, said Juan Mercagliano, area manager for pest detection and emergency projects with the California Department of Food and Agriculture. Warmer weather is one factor, he said, but the direct cause is tourists and returning vacationers who bring mangoes, pears and other "contraband fruit" from Hawaii and Southeast Asia.
The county maintains traps year-round throughout the region for general detection purposes. When flies are found, the state places additional traps to pinpoint the infestation. Mercagliano said one "site find" each was located in Burbank, North Hollywood and Sun Valley. He said 600 base stations are applied for every square mile of the infestation area. Mercagliano said there were few infestations last summer, but 17 outbreaks occurred in summer 1997.
The first treatment this season was done on July 16 and the second began Friday. Two more treatments will follow at 14-day intervals, Mercagliano said.