Spraying Is the Only Way, Medfly Panel Says : Infestation: Scientists advise against attempt to use sterile flies in L.A. and Orange counties because there are not enough available.

Scientists advising the state in its campaign to eradicate the Mediterranean fruit fly in Southern California said Wednesday that aerial spraying of pesticides remains the only viable weapon available to treat most of the infested area.

The five scientists told a press conference that a shortage of sterile fruit flies--which had been viewed as the only feasible alternative to pesticide spraying--has led them to recommend against changing tactics.

They said that as more sterile flies become available from two new breeding facilities in Hawaii they should be held in reserve against future infestation, or used to bolster the eradication effort in Whittier, where the use of sterile flies has continued throughout the regional infestation.

The panel’s recommendation must still be approved by the director of the state Department of Food and Agriculture and a decision is expected by Friday.

“We believe that program impetus and effectiveness will suffer an unwarranted setback with a change so near to the conclusion of the campaign,” the scientists stated in their recommendation. “Therefore, we are not recommending the phase-in of a sterile fly program in any of the bait treatment areas.”

At the same time, the scientists optimistically noted that the spraying--which has sparked protests from residents, politicians and environmentalists--appears to be working and the 8-month-old infestation could be eliminated by June.

The outcry from the public over aerial spraying has steadily increased over the last two months, although Gov. George Deukmejian and agriculture officials have remained resolute in backing the spraying program to eradicate the crop-destroying pest.

To ease anxieties about the extent of the spraying, agriculture officials have been promising for weeks that the two facilities in Hawaii could produce enough sterile flies by May to begin phasing out areas being treated with malathion.

But a majority of the science advisory panel said they doubted that a supply sufficient to breed the wild flies out of existence would be available by then. They predicted that it would probably be midsummer before the facilities are up to speed.

Panel chairman Roy Cunningham, a U.S. Department of Agriculture entomologist, said production problems with the one operating facility in Hawaii already have resulted in a decreased supply of sterile flies to the Whittier area. The state is temporarily making up the shortfall with sterile flies from Mexico.

Cunningham, however, said withholding the sterile flies from the spray zones will have a limited effect because spraying is scheduled to stop in most areas by the end of May if no new flies are found. Only the Pomona and Irwindale areas have spraying scheduled into June.

The panel also recommended that, beginning in April, spraying be stepped up in all areas from once every three weeks to once every seven to 14 days.

Cunningham said the expected warmer temperatures will make the fly more active and require a faster spraying schedule. Agriculture officials had previously announced that spraying would be increased in April.

The one scientist who was more reserved in his assessment of the eradication program’s progress was James R. Carey, an entomology professor at UC Davis. He said he was “cautiously optimistic” about the program, but concerned that there will be more outbreaks outside the current treatment areas.

Carey testified before the state Assembly last week that, because of repeated infestations in several areas such as Culver City and Baldwin Park, he believes the pest has become firmly established in parts of Los Angeles and Orange counties.

The majority of panel members disagree with Carey’s statements. But to put the issue to rest, the panel recommended a potentially costly and time-consuming program of saturation trapping to determine if small populations of Medflies have managed to elude detection over the years.

Instead of the typical five traps per square mile, the new program would involve thousands of additional traps that would have to be monitored for two years.

“It’s a definite major first step,” Carey said. “I see no other way to get at this.”

Meanwhile, a request by the state attorney general’s office for a temporary restraining order preventing the cities of Pasadena, Azusa and Lynwood from enforcing local ordinances against low-flying helicopters used in the malathion spraying was switched to U.S. District Court on Wednesday at the insistence of attorneys representing the cities.

“We think we’ll stand a better chance in federal court,” said Lynwood Mayor Robert Henning after Los Angeles Superior Court Judge Dzintra I. Janavs’ decision not to rule on the matter because the case had been filed in the higher court.

Calling the action “an obstruction,” Deputy Atty. Gen. Charles Getz said that the state would consider its options for a few days before deciding what to do. The state’s position, Getz said, is based on the belief that federal and state law supersedes a city’s jurisdiction over air traffic within its borders.

Times staff writer David Haldane contributed to this story.

MEDFLY SPRAYING MAP: B2