Conceding that they greatly underestimated the Mediterranean fruit fly infestation in Southern California, state and county agricultural officials Thursday ordered at least 12 more rounds of aerial pesticide spraying over a wide swath of largely residential neighborhoods.
The sprayings will be separated by one to three weeks, depending on the weather, a schedule that promises to extend the bothersome eradication effort well into spring.
"This is a much more serious infestation than anyone imagined," said Los Angeles County Agricultural Commissioner Leon Spaugy, who until now had insisted that the outbreak was well in hand.
Spaugy's view was changed during a three-day strategy session with a state scientific panel advising him on how to fight the outbreak, which began in August near Dodger Stadium.
As agricultural officials announced the new plan of attack, opposition to the pesticide spraying widened. Los Angeles County Supervisor Ed Edelman, whose East Los Angeles district is targeted for multiple doses of malathion, said: "Once, twice, OK, people will accept that. But 12 times? I question what the health effects might be."
Los Angeles City Councilman Richard Alatorre said he will introduce a motion today urging officials to re-examine alternatives to repeated aerial spraying. One option Alatorre suggests exploring is the creation of a "Medfly curtain" in an unpopulated belt between Los Angeles and California's farmlands; the buffer zone would get heavy doses of malathion.
Gov. George Deukmejian, under pressure from farmers to act swiftly to wipe out the crop-destroying pest, stood behind the scientists and agriculture officials. Deukmejian was advised of the decision to extend the spraying schedule but did not require officials to consult him beforehand, a spokesman said.
The new plan of attack means about a million residents in a crescent-shaped infestation zone that stretches across roughly 250 square miles from the San Fernando Valley to northern Orange County can expect to have their neighborhoods sprayed by low-flying helicopters 12 to 16 more times. This is roughly the average number of sprayings carried out statewide to combat the infamous Medfly infestation in 1981-82.
The announcement marks a dramatic departure from previous statements by county agricultural officials. They had insisted that the string of 12 Medfly outbreaks since August represented isolated infestations that could be wiped out with one or two pesticide sprayings. Their position was challenged in recent weeks by the panel of scientific advisers, which came to see the eradication effort as failing to check the Medfly.
Members of the advisory panel, emerging from three days of meetings in El Monte, described the infestation as the most puzzling they have seen.
"We have no explanation as to why this is happening," said Roy Cunningham, a veteran U.S. Department of Agriculture entomologist who heads the five-member panel. "There is no doubt that we now have a widespread, serious infestation."
Cunningham said he expects the infestation to continue to expand as long as the weather stays warm. Ideal fly breeding temperature ranges between 75 and 80 degrees.
The experts said they were forced into the repeated rounds of pesticide applications because of a lack of sterile flies, which are released by the millions to breed fertile flies out of existence.
"Our goal has been to keep pesticide use to a minimum," said Isi Siddiqui, assistant director of the state Department of Food and Agriculture. "But now we do not have the sterile fly resources and we have no alternative but to spray.
"Naturally we expect some opposition," said Siddiqui, a veteran of California's 1981 Medfly crisis, when delays in aerial spraying cost growers $100 million. "But our failure to spray now will result in a huge explosion of Medflies next spring. That would result in even bigger spray areas."
About 400 million sterile flies a week would be needed to fight the current infestation without repeated spraying. Only 130 million steriles a week are available from facilities in Hawaii and Mexico.
Since 1981, a California Food and Agriculture sterile fly breeding facility in Hawaii had been able to keep up with the demand for flies during smaller state Medfly infestations. But officials could in "no way" anticipate that the Los Angeles infestation would explode into an outbreak that would exhaust the supply of sterile flies, Siddiqui said.
About a dozen residents from neighborhoods targeted for more spraying confronted officials at their crowded news conference, challenging their claims that malathion poses no threat to health.
"We protest your blanket willingness to spray over and over again," said Virginia Johannessen, who lives in the Mt. Washington area of Los Angeles.
But Siddiqui cited a study prepared after the 1981 infestation that "did not show any adverse health effects" from spraying in Northern California, areas of which received up to 20 doses of malathion spray.