All’s Quiet on Fruit Fly Front--for the Moment : Medfly: Prolific pest hasn’t been sighted for two weeks, but officials say we haven’t seen the last of it yet. The return of warm weather may bring it back in force.

Two weeks have passed since any Medflies have been trapped in Southern California, but officials battling the pest say this is not yet cause for great hope.

The lull, they say, can be attributed to the colder weather, which slows the fly’s activities, coupled with the results of aerial malathion spraying. This has allowed officials to begin turning their attention to the spring when, as past infestations have shown, the pest could return in full force with the advent of warm weather.

So far in Orange County, Mediterranean fruit flies have turned up in Brea, Westminster and Garden Grove. The first Medfly was found Nov. 17 in a Brea guava tree, while the most recent sighting was Jan. 10 in Garden Grove.

“The real test will come in the spring,” Isi Siddiqui, assistant director of the state Department of Food and Agriculture, said Thursday.

The state plans to counter the pest’s expected spring offensive with increased malathion spraying, beginning in April. Millions of sterile Medflies, which have been in short supply, are expected to be shipped to the region in record numbers by May.

And on the political front, a veritable swarm of state and county officials have already mounted a meet-the-people campaign to explain the eradication program and plead for more public cooperation.

But Richard Rice, a professor of entomology at UC Davis and a member of the science advisory panel overseeing the state’s eradication program, said there is no way to tell how big a resurgence the flies will make and if the state has done enough to prepare for it.

“Essentially, we’re waiting for the other shoe to drop,” Rice said. “We hope it will be a real soft tennis shoe, but maybe it will be a big, heavy boot.”

Siddiqui said the slowdown in fly discoveries was expected. The cold weather extends the life cycle of the fly from about 30 days to as long as four months, meaning the pest breeds less and the population drops. But as the temperature goes up and fruit crops appear in spring and summer, conditions will again be good for the fly to breed prolifically.

The first stage in the state’s spring eradication program will be more intensive aerial spraying. Currently, infested areas are sprayed once every 21 days. That will increase to once every 15 days in April, and then every seven days in June, Siddiqui said.

By May, the state will also begin a far more ambitious plan to breed the Medfly out of existence.

At best, the state has been able to get about 80 million sterile Medflies a week from a U.S. Department of Agriculture breeding facility in Hawaii. But two new facilities in that state are expected to begin shipping about 200 million flies a week by May, and the rate could go as high as 400 million by June, Siddiqui said.

“If we get 400 million we should pretty much be able to phase out aerial spraying, except in areas with new finds,” he said. “Getting those flies is our top priority.”

Siddiqui said the shipments of sterile flies are important to help blunt the growing political opposition to aerial spraying.

The cities of Garden Grove, Huntington Beach and Westminster filed suit against the state last month to stop the spraying campaign. State Sen. Art Torres (D-Los Angeles) introduced two bills last month that would effectively stop the state’s aerial campaign by banning repeated malathion spraying and requiring proof of the safety and effectiveness of the pesticide.

Cities from Brea to Duarte have passed resolutions demanding an end to aerial malathion spraying.

To counter the opposition, state officials have pressed a public relations campaign. Last week, officials announced the creation of a malathion health advisory panel that will have the dual mission of advising the state on the possible health implications of the pesticide spraying and educating the public on its findings.

The panel, which could begin meeting this month, will be made up of Southern California health professionals, as well as local physicians, university specialists and poison control experts.

Next week, Siddiqui and other state officials will begin holding weekly briefings to keep the media informed of the eradication campaign’s progress.

Siddiqui said the department also has launched a renewed effort to talk with local elected officials who, he conceded, were poorly informed by the department during the early, frantic days of the eradication program.

“We weren’t doing it as methodically as we’d like,” he said. “Now that we have stabilized the situation, we’ll reestablish contact.”