Authorities Brace for Possible Infestation After Medflies Found : Fruit: Officials lay traps and treat trees but refuse to speculate on aerial spraying of malathion. The insects could cost county millions.

A day after confirming the frightening discovery of a pair of fertile Medflies in a Camarillo orchard, federal, state and local authorities descended upon the area Saturday--laying traps, inspecting fruit and hosing down trees with the powerful chemical malathion.

But even as they braced for the possibility that thousands of other Medflies may already have infested the area, entomologists refused to speculate on whether they will have to resort to aerial spraying of malathion--a controversial way of eradicating the destructive pests before they establish themselves.

The Medfly discovery is significant because it could set off a brutal assault on the most profitable sector of the county’s $848-million agriculture industry--fruit.

Agriculture officials and entomologists did not report any additional discoveries of Medflies on Saturday.

By setting traps, they hoped to determine how many other Medflies are in the area. For every fertile fly trapped, officials said, there might be 1,000 other fertile flies nearby.

It will take several days before they size up the extent of the problem and make decisions on how to contend with it, they said.

“What type of treatment strategy that ultimately will be put in place, it’s too early to make that decision,” project spokesman Douglas L. Hendrix of the federal Department of Food and Agriculture said when asked about aerial spraying or other Medfly-fighting measures.

But he acknowledged the devastating impact the Medfly could wreak on the county’s agriculture industry.

“If you have any fruit fly introduction into a production region, it is always a concern, because they have the ability to exponentially increase,” Hendrix said.

Elisabeth Brokaw, a leader of the Ventura County Fruitfly Action Cooperation Task Force, said professional and back-yard growers within about a 4 1/2-mile radius of the discovery site should not move fruit.

Initial reports from members of the county’s Medfly task force incorrectly said that a quarantine had already been ordered on all fruit within that radius. That has not happened, officials said Saturday, but an announcement is expected Monday on whether one will be imposed.

The quarantine decision will be made by the U.S. Department of Agriculture, with state and local officials, said Rex Laird, executive director of the Ventura County Farm Bureau.

Residents and farmers near the Medfly discovery site--northeast of Upland and Lewis roads at the campus of St. John’s Seminary--were trying to figure out the real meaning of the find.

Farmers, whose entire livelihood is at stake, were doing the most guessing, trying to get accurate readings of the impact of the discovery itself and of the damage a full-scale Medfly infestation could cause. For example about 30% of the county’s lemons are shipped to Japan, bringing in more than $50 million, but Japan could embargo those shipments if an infestation has occurred.

What would happen if there are indeed thousands of Medflies in the area? The idea of a possible quarantine frightens some farmers.

“It’s worse than an earthquake or flood or anything you can think of,” said rancher John Grether, whose citrus and avocado groves are less than four miles from where the two flies were found.

Laird agreed. “The fact of the matter is, with the economy and the times we are in now, we can ill afford to be in the situation we are in.

“It’s going to hurt a lot of people,” he said. “There are going to be a lot of people out of work, if in fact it turns out to be an infestation. It’s going to be devastating.”

Deborah House, who owns property less than a mile from the discovery site, worries for those neighbors who make their living off the land.

“This is big agriculture country. A lot of this stuff just isn’t back-yard fruit. It’s income. Groves.”

Early Saturday morning, workers from the Cooperative Medfly Project in Los Angeles County arrived on the 200-acre St. John’s campus armed with bug-killing devices and other specialized equipment.

Carrying heavy backpacks loaded with high-powered hand-spraying units that looked like those used to sandblast parking lots, the workers spent two hours blowing a blend of poison and bait on the foliage within a 200-meter radius of the tree where the flies were trapped, on the crest of a hill near student dormitories.

The molasses-like spray is 10% malathion solution and 90% corn-syrup bait.

At the same time, another team of workers laid hundreds of Medfly traps, most of them in the square-mile area around the discovery site.

A third team snatched pieces of oranges from the trees around the site, slicing them up in an attempt to determine whether they had been infested with Medfly larvae.

Sitting in a circle on empty white buckets turned upside down, Rogelio Rodarte and two co-workers from the state Department of Food and Agriculture sliced off thin pieces of the fruit and placed them under a microscope to detect any larvae.

They found some harmless larvae from vinegar flies, Rodarte said, but no Medfly larvae. He would know if the larvae were Medfly, Rodarte said, because they would have two brown dots on the tail. “With the naked eye, they all look the same,” he said, lifting his magnifying glass to an orange slice.

About a mile away, Linda Charpied said she has gotten used to insects around her house in the middle of miles of orchards on Seminary Road.

“I’ve had a lot of allergies from just regular spraying that they do on the regular trees,” said Charpied, a nurse and part-time actress whose husband, Michael, operates the boilers for St. John’s.

“If you’re not concerned about the Medflies, you have to be an idiot,” Charpied said. “But if you live here, you have to expect this.”

Times staff writer Stephanie Simon contributed to this report.

* MALATHION

As officials assess situation, residents take sides on aerial spraying. B5