Even before Camarillo residents learned that their back yards would be dusted with pesticide, a private helicopter company in the San Joaquin Valley was making preparations for the military-style operation.
Under a two-year contract with the state Department of Food and Agriculture, San Joaquin Helicopters dispatched Bell 204 Hueys earlier this week to survey the rolling hills of Ventura County.
Weather permitting, the pesticide runs begin Wednesday night.
Flying in formation, three red-and-white helicopters will spray a mixture of malathion and corn syrup bait over Camarillo starting at 9 p.m.
The flights will take off from the Camarillo Airport, where the helicopters will have been loaded in secured areas with 90 gallons of the malathion mixture.
Such operations will take place 10 to 12 times during the next six months at two-week intervals to kill any Medflies that emerge after surviving earlier sprayings as eggs or larvae.
For the Delano-based company, California's latest air attack against the Mediterranean fruit fly is nothing new.
Since the early 1980s, San Joaquin's pilots and equipment have played a central role in the effort to wipe out the pernicious pest. Most recently, they were hired in February to spray an 18-square-mile area over Corona in Riverside County. Before that, the company carried out eradication efforts over portions of Los Angeles County in 1989 and 1990.
Although both of those operations sparked fierce opposition from residents--including death threats to the Cooperative Medfly Project workers--San Joaquin officials said they expect little hostility in Ventura County.
"The people in Ventura County seem to be a whole lot more understanding about why spraying is necessary," company owner Jim Josephson said. "I think that's because there is so much agriculture."
Helicopters are used instead of planes because they can drop pesticides more precisely in a small area, and because they are safer for flying at night.
Meanwhile, some growers throughout the 86-square-mile quarantined area are expected to begin hiring their own pilots for malathion spraying.
Under the rules of the quarantine, farmers who want to sell their unpicked fruit that is a host to the Medfly must pay to have their crops sprayed with malathion four times within a 30-day period. Then the crop must be inspected before it can be shipped from the quarantine area.
As a result, some growers with unpicked fruit inside the quarantine area, but outside the 16-square-mile eradication zone, expect to treat their orchards with the pesticide.
Despite the furor that malathion spraying has caused in populated areas, growers routinely hire helicopter crews to dust local vegetable crops, and sometimes fruit orchards, with the malathion. The pesticide is commonly used to control grasshoppers, boll weevils and mosquitoes.
"It's done on a regular basis, depending on the pest levels," said Rob Scherzinger, a pilot for Aspen Helicopters Inc. of Oxnard, the largest local crop-dusting company.
Since Medflies were first discovered near Camarillo, dozens of growers have contacted Aspen Helicopters to get information about aerial spraying.
Although no pesticide runs are scheduled yet, Scherzinger said several avocado growers have plans to spray their unpicked trees with the series of four treatments. "Everybody's kind of taking a wait and see attitude now, but I guarantee by Tuesday or Wednesday we're going to be smoking."
Scherzinger said the spraying will cost growers $10 to $12 an acre for a malathion treatment, a price that is cheaper than other crop-dusting because of the low-concentration of pesticide that is applied.
Under the rule of the state-imposed quarantine, farmland that falls within the 16-square-mile eradication zone will be sprayed by San Joaquin's helicopters. And growers with unpicked fruit will only have to pay for an additional two or three treatments.
In both urban and agricultural areas, the same concentration of pesticide will be sprayed. For every acre of land, 1.2 ounces of malathion will be dispersed, said Larry Hawkins, spokesman for the Medfly Project.
But in other ways, the sprayings differ according to land-use. Flights over orchards and farm fields will be done at low altitudes during the daytime. In contrast, the urban spraying will be done at nighttime at altitudes of 300 to 700 feet.
Thus, flights over orchards are more precise, while urban spraying is intended to scatter the pesticide over broad swaths of houses, parks, schools and businesses.
Correspondent Kay Saillant contributed to this article.