Possible Aerial Spraying Draws Censure, Support : Malathion: Though officials have not even speculated on whether the pesticide will be used against Medflies, debate on its merits and drawbacks has already begun.

From two dead flies, the nightmares spring: helicopters spewing brownish-pink poison, demonstrators massing in protest, politicians shouting to stop the spraying.

Such scenes have been played out, to one degree or another, in Riverside, Orange and Los Angeles counties--in almost every agricultural region where the dreaded Mediterranean fruit fly lurks.

The discovery of two fertile female Medflies in Camarillo--the pests’ first known incursion into Ventura County--has raised fears of a repeat performance here.

Federal and state officials emphasize that they’re still far from a decision on whether to begin aerial spraying of malathion, a pesticide that kills adult Medflies.

They must first figure out whether the two female Medflies, found drowned in the bottom of a glass-bottle trap, represent the vanguard of a major incursion or simply a pair of unlucky wanderers. Even if they determine that the fruit-devouring insects have invaded Ventura County, they might decide on other, more subtle, means of control.

*

“Aerial spraying would definitely be a last resort,” said Elisabeth Brokaw, a leader of the county’s Medfly task force.

Even as a last resort, however, aerial spraying remains hugely controversial. Anticipating a battle, local farmers, environmentalists and scientists are already preparing their arguments.

The debate, historically, has been fierce.

Pro-spraying factions emphasize that malathion is a garden-variety insecticide, used in countless back yards to zap aphids, mealy bugs and other common pests.

“It’s a wide-scope insecticide,” said Max Waggoner, manager of the Mound Garden Center in Ventura. For home gardeners battling bugs, he routinely recommends malathion. It’s effective, he said, and relatively inexpensive--a pint sells for $8.99.

But few people complain when a neighbor sprays the stuff on back-yard roses. When helicopters buzz overhead after bedtime, sprinkling the pesticide over chimneys and jungle-gyms, organized protests erupt.

To monitor citizen concerns, officials have set up malathion hot lines after previous aerial sprays. Callers have complained of nausea, diarrhea, vomiting, rashes and respiratory problems.

“Malathion spraying is not safe,” concludes Corey Deetzer, a member of the Conejo Valley Organic Gardening Club who has researched the chemical.

*

Officials at the California Department of Health Services, however, have repeatedly announced that spraying in urban areas poses no significant health hazard. They point out that many of the symptoms reported after malathion spraying can stem from the flu or even the common cold.

“Some people in the population are sensitive, especially the elderly and people with allergies,” Brokaw said. “But most people in the community won’t even notice it at all.”

While malathion kills insects, state officials say the pesticide breaks down easily and harmlessly in people, because the human body contains enzymes capable of handling the chemicals. Still, in a 1993 fact sheet on malathion, state health officials recommended that people stay indoors during aerial spraying, rinse down outdoor play areas, wash skin and clothing that comes in contact with the pesticide, and scrub home-grown produce.

Such a long list of precautions alarms malathion opponents.

Many foes also object, in principle, to widespread spraying of chemicals.

“You know how many millions of tons of poisons are dumped on this planet by accident,” said Cassandra Auerbach of the Conejo Valley Sierra Club. “We don’t need any more. And that’s what pesticides are--poison. They kill life.”

Farmers readily admit that they have trouble countering the visceral emotional reaction against pesticide spraying.

“Aerial spraying really upsets people a lot, psychologically if nothing else,” Brokaw said. “But if you step back and take a look at it logically, you’ll see that spraying can make sense.”

*

The growers’ best arguments rest on dispassionate calculations. They explain that a Medfly invasion could destroy the agricultural industry. Ventura County’s crops alone were valued at $848 million last year-- but the agricultural economy stretches way beyond the fields to touch packing houses, trucking firms, irrigation consultants and more.

“We’ve been trying to prepare the public because this is a very serious situation for agriculture in Ventura County,” citrus and avocado rancher John Grether said. “It has such an impact on so many jobs, and on the whole way we do business.”

Even though his groves lie just four miles from the Medfly discovery site, Grether believes that aerial spraying should be only a last resort. “I hope it wouldn’t come to that,” he said. “It really tends to polarize the community.”

Although pest experts have battled the Medfly for more than a decade, they have not yet determined which method of attack works best.

An intensive spraying campaign that started in 1989 sprinkled malathion across 536 miles in four Southern California counties, at a cost of $52 million. But just one year after that effort ended, trappers found 25 flies in Koreatown in Los Angeles. And by late 1992, several hundred Medflies had been spotted--many popping up in areas that had recently been sprayed with malathion.

“I’ve got tons of literature here that proves that malathion spraying is not safe, is not effective, and is very expensive,” Deetzer said.

As a more low-tech way of controlling the Medflies, officials have been releasing 780 million sterile male insects a week into the Los Angeles Basin. They hope the sterile Medflies will mate with the females--a coupling that would yield no offspring and therefore thin the ranks of future generations.

*

Officials have also imposed a quarantine on a 1,500-square-mile stretch that reaches into Los Angeles, Orange and San Bernardino counties. The quarantine bans people from transporting fruit grown in that region.

Yet trappers keep finding Medflies.

Just last winter, the discovery of several Medflies in the Riverside County cities of Corona and Norco prompted officials to spray 18 square miles with malathion, provoking a furious citizen uproar.

Malathion opponents in Ventura County hope to avoid such a clash by addressing the subject of spraying early and often. Deetzer plans to rally a group of anti-spraying activists and begin lobbying politicians soon.

“Rather than re-create the same health risks and ineffective programs here in Ventura County, we need to formulate an intelligent pest-management plan,” she said. “It is possible.”

Times staff writer Mary F. Pols and correspondent Julie Fields contributed to this report.