Medfly Peril Spreads to Orange County : Infestation: Escalating outbreak is described as ‘grave.’ Spraying ordered for Brea after the latest discovery of the pest.

A Mediterranean fruit fly infestation in Los Angeles County appears to have crossed over to Orange County, officials reported Monday, and the state’s leading entomologist described the escalating outbreak as “grave.”

Orange County officials reported finding a pregnant Medfly in Brea, a city that sits just south of the county line and near the locations of other fly discoveries. Aerial pesticide spraying was ordered.

The latest extension of what appears to be a crescent-shaped infestation area through the San Gabriel Valley and beyond came as Los Angeles officials scheduled an aerial application of the pesticide Monday night over a 12-square-mile section of the East San Fernando Valley, at the western extreme of the infestation.

Two helicopters took off from El Monte Municipal Airport at 8:45 p.m. for the spraying operation, which was expected to take up to six hours.

Officials said that because of the extraordinary number of Medfly outbreaks in Los Angeles, the Orange County find and any other new ones will probably require multiple aerial sprayings. With the Brea spraying, a total of 132 square miles of largely residential neighborhoods has been sprayed for Medflies since August.

Officials originally maintained that the infestation consisted of several isolated outbreaks, but in recent weeks, most have changed their position and become convinced that they are battling a single, large infestation.

An acute shortage of sterile Medflies, which are released by the millions to breed the fertile population out of existence, has left no alternative but increased pesticide spraying to battle the infestation, officials said.

“The situation is grave,” said Roy Cunningham, the leading entomologist on the state’s Medfly scientific advisory panel. “We are nearing the point where we have to consider alternatives. . . . Nobody wants more spraying, but we have to face the fact that this is our fall-back.”

So far, state and county officials have sought to limit spraying to a single--and most recently, double--application of the pesticide malathion. During the 1981-82 statewide infestations, as many as six applications were common.

Orange County Agricultural Commissioner Jim Harnett, who said spraying of a 10-mile zone straddling the Los Angeles-Orange County line is tentatively set for Nov. 30, conceded that “an additional treatment might be called for if there is a delay in receiving steriles.”

In Los Angeles, county Agricultural Commissioner Leon Spaugy said that “given the shortage of sterile flies and the probability of additional fly finds, we will be looking at dual applications” in such newly discovered infestation zones as Sylmar and North Hollywood. Already parts of the San Gabriel Valley and East Los Angeles are awaiting a second application of pesticide next Tuesday and Wednesday.

State scientists insist that malathion poses no health risk.

Kevin Brett, a spokesman for Gov. George Deukmejian, on Monday reiterated that the governor will approve “whatever steps are necessary” to eradicate the pest considered a potent enemy of California agriculture. The governor’s office has heard few complaints about the spraying, he said.

Officials of the state Department of Food and Agriculture, which is run by Henry Voss, a former farmer, has the authority to use aerial application “as they deem necessary,” Brett said.

Politicians from Orange County voiced staunch support for aerial spraying Monday.

Supervisor Gaddi H. Vasquez, whose district includes Brea, said: “I think it’s imperative to deal with this in a swift and decisive manner so we keep the area that needs to be sprayed to a small and definable area. . . . I have not heard any resistance.”

State Sen. John Seymour (R-Anaheim) said he does not “look forward to being sprayed on . . . but I think we need to do the safe thing, and that is spray as soon as possible.”

In their comments, the Orange County politicians seemed to assume basically the same posture as their Los Angeles counterparts, expressing empathy for residents who must put up with the nuisance of pesticide spraying, while insisting that the need to protect agriculture from the Medfly is the greatest concern.

While the infestation thus far has been contained to urban sections of Los Angeles and Orange counties, its spread to the San Joaquin Valley could harm the state’s $16.2-billion agricultural industry.

The Brea fly alarmed at least one grower representative. Barbara Buck, spokeswoman for Western Growers Assn., a statewide group based in Irvine, called the Brea infestation “a serious find” in light of Orange County’s $225-million-a-year citrus and nursery industry.

“It is a tremendous threat to our industry,” Buck said. “We’re sensitive to public concern, but the Medfly does need to be eradicated.”

The prospect of widespread spraying comes at a time of growing citizen irritation. The nighttime forays of helicopters force residents to cover cars with protective plastic and bring pets inside.

About 15 demonstrators gathered at Sunset and Crescent Heights boulevards in Hollywood late Monday afternoon to protest aerial spraying. They carried signs inviting motorists to “Honk if your are against malathion spraying.” Randall Toller, who identified himself as chairman of the United States Green Party, described the demonstration as a success, even though it was small.

“We did raise public awarness of the safety of malathion for aerial spraying,” he said.

Spaugy, however, warned that the mild doses of pesticide should be tolerated by residents because if the infestations are “allowed to get away from us, pesticide use will increase.”

Times staff writer Dave Lesher contributed to this report.