It’s the Invasion of the Medfly Snatchers : Spraying: The sleep-shattering roar of helicopters means one thing: You’re in the malathion battle zone.

Kim Walters heard the deep, distant pounding from the heavy rotors of helicopters. A trio of choppers with pulsating lights veered toward his hillside home in single formation. It was 9:30 Thursday night in Highland Park, and the Medfly war had started.

Walters rushed to his front porch carrying a huge sheet of plastic.

“My parakeet is sitting on eggs,” he said, carefully covering the outdoor bird cage. “I can’t let her get sprayed. She can’t be disturbed.”

Five miles southeast of the parakeet cage and an hour later, outdoor diners perked up to the same sky rumble.

It escalated to a roar. They dashed for shelter, grabbing their tray of french fries.

Later, in midnight darkness, Susan Halpin zipped through her South Pasadena home in her nightgown, shutting doors and windows to quiet the helicopter’s din. But the deafening chopper woke her daughter anyway, and she heard a whimper from the bedroom.

It was another night of fighting in the Medfly spray zone. Another night of the government’s intensifying, $10-million attack on the notorious crop-destroying pest. On this Indian summer eve, the residents of 200,000 homes in a 22-square-mile sector of East Los Angeles, Pasadena and San Marino were subjected to malathion sprayings. Since August, more than 1 million households in Los Angeles County have fallen within spray zone boundaries.

Under Gov. George Deukmejian’s orders, helicopters can swoop down on neighborhoods with only 24 hours’ notice. The three white choppers outfitted with 1,466-gallon malathion tanks Thursday night hovered 300 feet above city streets, aiming spray nozzles toward homes and yards.

“When you see those lights flashing and look out at those helicopters it’s like a military force is sweeping down on you,” said David Sommerland, 43, of Highland Park.

For many, the almost weekly aerial assaults have been an annoying, even frightening, intrusion. And it is far from over. At least three more sprayings are slated for the San Gabriel and San Fernando valleys this month.

“Some people are just beside themselves because we are invading their homes and violating their space,” said Michael Pearson, a Los Angeles County agricultural inspector. “We try to sympathize and empathize with them. We tell them that they must understand this is a time of emergency.”

In short, residents must fend for themselves.

They buy tarpaulins by the yard. They rush into the chilly night air to cover their cars with protective sheets, trash bags and cardboard. They rise early in the morning to hose down patios. They make children wash their hands after playing outside.

A few of the more cautious evacuate their homes for the night when the Medfly helicopters take to the air.

“We have no control over this. No vote on this,” said a distraught Federic Smith, a 24-year-old cancer researcher. “We have to totally go on faith in the government that the pesticide is safe.”

Worst of all, the citizenry has no one to blame but themselves for this “calamity,” said Los Angeles County Agricultural Commissioner Leon Spaugy. After all, people smuggle fruit infected with Medflies across town.

Now they must learn to live with the consequences.

In the hours before the big spray Thursday night, anxious callers deluged the phone banks of the county’s Medfly hot line. They fired off questions to operators with maps and charts covering their desks like army sergeants.

“Yes ma’am, you should put your dog inside if you don’t want him to get sticky,” operator Georgette Burgess said in a firm but reassuring voice. “But even if he does get sprayed, don’t worry. The only thing that will die are his fleas.”

Across the room Sandy FitzSimmons gave her caller a mini-biology lesson.

“No ma’am. It is only a minute amount of pesticide in the spray. The Medflies eat it. It goes into their stomach and they die. That’s all.”

Out in the spray zone, the Ziko family, whose Alhambra home was sprinkled with malathion two weeks ago, found themselves in yet another spraying area Thursday night while at an outdoor restaurant. At the first hint of the rotor beat, the family members took their food and ran for cover beneath a patio shelter.

“We thought of running to the car, but we didn’t want to get sprayed,” Kathy Ziko said. As the copters turned above them and headed west, Leo Ziko offered advice to residents who may be jarred awake by aerial thunder.

“I go to sleep at night thinking of helicopters so I won’t be afraid when I hear them coming,” the 16-year-old said.

Words that could have helped Susan Halpin, who was awakened by the helicopters shortly before midnight.

“It’s a very eerie feeling to know that this stuff is being sprayed on you from these big helicopters,” said Halpin, a 35-year old mother of six.

The next morning, her young daughter told Mommy that she had awakened in fright because of the helicopter noise. Time for Halpin to explain about the Medfly war and why the back-yard trampoline has to be washed before children can play outside.

There were daring citizens too. Or maybe just unflappable.

Chris Jacobs decided that the night malathion was sprayed over Pasadena would be a perfect time for a nocturnal bike ride. Undaunted by the choppers two miles south of Colorado Boulevard, the 28-year-old radio astronomer wheeled his 10-speed onto the road at 1 a.m.

“I needed a break and decided to go for a ride,” Jacobs said.

Not far away a couple leaned against their car in an amorous embrace.

“The helicopter? Oh yeah, I know they are coming,” said Rich Honanie, 24. “We’ll go inside when they come.”

The morning after the spray, residents turned garden hoses on the sticky malathion residue, which can ruin the paint on cars left in the sun.

Joe Kopicka, a 48-year-old San Marino attorney, was out at 7:30 a.m. washing the pesticide off his 1979 Chevrolet El Camino, the car he uses to drive to his beach house.

Hugo Estrello was hosing down the outside walls of his house and porch because in a few hours he would bring his wife and newborn son home from the hospital.

“They told us the spray is safe, but I figured I better play it safe,” Estrello said.

Pedro Carvajal, manager of the Alhambra Car Wash, was perhaps one of the few people in Los Angeles who looked forward to the spraying. Thanks to the Medfly infestation his family will enjoy a bountiful Christmas. By the end of the day, 1,250 cars had passed through his wash cycle, 500 more than usual.

“Good money for the holidays,” he said, running to direct traffic that had begun to clog Atlantic Boulevard as anxious motorists competed for a place in the carwash line.

Not everyone was taking the cleanup in such good humor, though.

In the morning glare Connie Berg grew angry as she surveyed the rose-colored droplets on her white Volkswagen van. The South Pasadena woman was so angry that she packed up her two children and left town for a pesticide-free day at her mother’s house.

“I’m a ‘70s-era environmentalist, and there is pesticide all over my car, the lawn, the kids’ swing set,” she said. “I don’t want my kids tumbling in the grass today.”

She was mad enough to renew her membership in the Sierra Club.

“It’s so frustrating because I have no say in this, no choice. There is nothing I can do except wash everything,” she said. “I am being forced to support agribusiness, all because of this insect.”