A $2-million effort to rid Los Angeles County of the latest infestation of the Mediterranean fruit fly has succeeded and is likely to end in the next few weeks, according to county and state agricultural officials.
"At this point, I don't know of anything that is going to interfere with (the eradication project) from being successfully completed," Los Angeles County Agricultural Commissioner Paul B. Engler said in an interview.
He added, however, that a ban on the movement of fruit and vegetables from a 93-square-mile quarantine area centered in Maywood is expected to remain in effect until early next year.
Crop Enemy No. 1
The Medfly is at the top of the list of crop-damaging pests, officials said, because it preys on more than 250 varieties of produce, reproduces rapidly and survives in a range of climates.
The Medfly quarantine was declared Aug. 17 after county workers discovered three female flies in Maywood and Boyle Heights. In the following weeks, county, state and federal officials fought the infestation with one-time aerial sprayings of malathion pesticide in the Maywood-Bell and Boyle Heights areas and with the release of more than 400 million sterilized male flies from an airplane and trucks.
The sterilized flies, spread over a 110-square-mile area, act as a birth control device and, in effect, allow female Medflies to literally breed themselves out of existence. They are bred and sterilized in a laboratory in Hawaii, then shipped to California in two-foot-long plastic containers that resemble large sausages.
The last wild Medfly was trapped Sept. 8 in the 2800 block of Rimpau Boulevard in Los Angeles, near La Brea Avenue and Jefferson Boulevard, Engler said. It was the only one of the 42 wild flies trapped during the project that was discovered outside the Maywood-Bell and Boyle Heights areas, he added.
No new wild flies have been found since then. The final release of sterile male flies should occur later this month, said Engler and Gera Curry of the California Department of Food and Agriculture.
Engler said authorities avoided a repetition of the devastating Medfly invasion of 1980-81 in Santa Clara and Los Angeles counties--and the estimated $200 million in eradication costs and crop losses--by acting quickly to "knock down" the spread of the pest with aerial sprayings.
The two one-time applications of malathion allowed officials to use sterile flies to eradicate the rest of the Medflies, rather than rely on continued sprayings, Engler said.
Although officials have said the malathion sprayings pose no health risks, the pesticide does damage the paint on cars and trucks and has proven controversial.
'The Way to Go'
"There is no doubt about it that a 'knock-down' application of (malathion) bait from the air is the way to go," Engler said. An attempt early in the recent infestation to apply the pesticide from the ground proved too time consuming, the commissioner added.
The $2-million cost of the Medfly eradication program will be borne equally by the state Department of Food and Agriculture and the U.S. Department of Agriculture, Engler said. The county's expenses, which mainly involve paying workers to set and monitor Medfly traps, will be picked up by the state, he added.
Meanwhile, quarantines to prevent the spread of the peach fruit fly and the Oriental fruit fly remain in effect in a 100-square-mile area surrounding Los Angeles International Airport and an 81-square-mile zone centered in Hawaiian Gardens.