Thirty Mediterranean fruit flies were found in traps in the Palms area over the weekend, prompting agriculture officials to announce Monday that helicopters will spray malathion-laced bait over a 35-square-mile region in an effort to stop the infestation.
Weather permitting, the pesticide spraying will begin at 10 p.m. Wednesday, lasting about eight hours, over a densely populated Westside area.
The spraying will cover not only Palms but parts of West Los Angeles, Culver City, Beverly Hills and Los Angeles. Officials said that the rough boundaries of the spraying zone are Santa Monica Boulevard on the north, La Brea Avenue on the east, Slauson Avenue on the south and the San Diego Freeway on the west.
At least 100,000 people live in the area, officials estimate.
Federal, state and local agricultural authorities agreed to conduct the spraying after adult flies were discovered in 1,300 traps set in fruit trees. Officials also found evidence of fruit fly larvae in several trees.
“There definitely is an infestation,” said Bob Donley, deputy director for environmental protection with the Los Angeles County agricultural commissioner’s office.
Donley added that a second spraying may be required if the first is not effective.
“If another application is required, we would do it the following week,” he said.
Agriculture officials began setting fly traps in the Palms area after discovering a single Medfly on a Culver City property Sept. 26.
Four days later, three more flies were found in Palms, and over the next two days authorities gathered 27 more flies. Officials found the most flies along Durango and Canfield avenues near Kincardine Avenue.
Donley said there are no links between the Medfly discoveries in Palms and an earlier infestation in the San Fernando Valley that resulted in aerial spraying of malathion in July and the release of millions of sterile Medflies in an attempt to breed the pest out of existence.
Officials expect to continue monitoring that situation by setting traps for flies in Northridge and Reseda for another month.
Since Sunday, Donley said, agriculture officials have treated at least eight affected properties in Palms with a ground-sprayed bait of corn syrup mixed with malathion and plan to treat at least 37 more. The pesticide kills the flies by acting on their central nervous systems.
On Monday, representatives from the county, the California Department of Food and Agriculture and the U.S. Department of Agriculture agreed to begin warning Westside residents that aerial spraying is necessary.
Although officials continue to maintain that the pesticide poses no threat to humans, the state has printed warning leaflets for 100,000 Westside residents, answering basic questions.
More than 250 members of the California Conservation Corps fanned out through the affected area Monday to distribute the leaflets, which generally advise residents to cover cars, bring patio furniture indoors and hose down their yards after the spraying.
Agriculture officials consider the Medfly a “super pest” that attacks more than 250 types of fruits, vegetables and nuts, posing a serious threat to the state’s multimillion-dollar agriculture industry.