10,000 Acres Sprayed in Effort to Kill Medflies

Aerial spraying of the pesticide malathion was carried out Monday over the northwest San Fernando Valley, where two Mediterranean fruit flies were discovered last week and possibly a third on Monday, officials said.

Dr. Doug Arterberry of Northridge Hospital Medical Center, who was in charge of one of two Medfly hot lines set up to answer questions about the spraying, said residents need not worry about a possible health hazard.

“It’s not the chemical warfare that some people would have you believe,” said Arterberry, who is also director of the toxic center at the hospital. “For the vast majority of people there is absolutely no problem.”

Two helicopters began spraying the pesticide about 10 p.m. over a 16-square-mile area bounded by Devonshire Street on the north, Sherman Way on the south, Wilbur Avenue on the west and Haskell Avenue on the east, state Department of Food and Agriculture officials said. The spraying was to last about three hours.

Gera Curry, a spokeswoman for the state agriculture department, said that the 1,000 gallons of spray used Monday mostly consisted of a syrupy corn-based protein bait. She said only a small amount of the pesticide malathion, equal to about two ounces per acre, was mixed with the bait. The area sprayed Monday is equal to 10,240 acres.

Gov. George Deukmejian issued a local declaration of emergency to allow the spraying after two of the flies--which prey on more than 260 kinds of fruit, vegetables and nuts--were discovered in traps Wednesday. The female flies were found in separate traps less than 1 mile from each other in Northridge.

Los Angeles County agriculture officials said that because the traps are designed primarily to lure male flies, the fact that female flies were found indicates a large infestation. “That we found females indicates that they were looking for males to mate,” said county Agricultural Commissioner Leon Spaugy.

On Monday, a third insect, which authorities believe to be a Mediterranean fruit fly, was found by a county entomologist in a trap just north of Sherman Way near Baird Avenue in Reseda. The fly was caught about 1 1/2 miles from where one of the flies was discovered Wednesday, Spaugy said.

Spaugy said that the fly was flown to a state agriculture laboratory in Sacramento on Monday for positive identification. That identification is expected today and will include the sex of the fly, officials said.

In any case, Spaugy said finding the third fly was “not surprising or unusual. We fully expected to find additional flies.”

Meanwhile, there are no plans for more aerial sprayings, said Thomas K. Palmer, area manager for the state Department of Food and Agriculture.

Curry said the aerial spraying Monday would be followed in a few weeks by the release of millions of sterile male flies. The flies are raised at a state of California laboratory in Honolulu, and officials have tentatively scheduled Aug. 4 as the date to begin releasing them.

The females breed themselves out of existence by mating with the sterile male flies, Curry said. “It’s Medfly birth control,” she said.

She said about 20 million sterile flies will be released the first week and that as many as 100 million sterile flies could be released within a four-week period.

Spaugy underlined the safety of the insecticide malathion, saying it is “the most-studied pesticide in the world. It’s the safest material you can possibly use--and still eradicate the Medfly.”

Arterberry, whose office had been averaging from 150 to 300 calls a day from concerned residents, said only those people with chronic bronchitis, emphysema or asthma might be affected by the spraying. Arterberry said an insecticide such as malathion could cause an asthma attack. “We expect two or three” of these type cases to be reported, he said.

Palmer said the aerial spraying cost the state from $50,000 to $60,000. He said it was unknown how much the entire operation--including ground spraying and the use of sterile flies--will cost.

However, Curry said a similar operation in East Los Angeles, where 42 adult Medflies were discovered last year, cost about $2 million.