The Folks Who Tend Those Medfly Traps : Infestation: It’s a tedious job, but the trappers wear ‘significant finds’ like a badge of honor. ‘It’s big stuff,’ says one.

The fly trapper was mad. Arturo Lomeli was rinsing a strainer filled with dead flies, and not one of them appeared to be the kind of fruit fly that he and other county agriculture inspectors would consider a “significant find.”

No Mediterranean fruit flies. No Oriental fruit flies. No Mexican fruit flies. Not even a melon fly. Just ordinary, non-threatening houseflies.

While this no doubt would please state officials fighting an infestation of Medflies--and millions of residents who along the way have known the nuisance of helicopters spreading malathion over their property--fly trappers like to live up to their job description. They like to trap bad flies.

So-called “significant finds” are considered badges of honor among the scores of trappers who have fanned out across four Southern California counties in the widening war against a swarm of invading fruit flies. Inspectors often keep score among themselves to ward off the boredom of peering into the more than 50,000 traps spread over the region to monitor infestations.

“Last year was a good year for me,” said Lomeli, a three-year veteran of Los Angeles County’s Fruit Fly Eradication Program, a $1-million-a-year trapping project. “I found seven Medflies, five Mexican and four Oriental fruit flies, including three in one trap. Some inspectors go months without finding one. But when they do, it’s big stuff.”

Now nearly a year old, the eradication effort is focused more than ever on trappers like Lomeli. If they continue to turn up only houseflies in their traps of cardboard and glass, it would mean that the long, controversial campaign of malathion spraying has been successful and can be shut down.

If fruit flies start turning up in the traps, however, the state would probably respond with a stepped-up campaign of spraying.

Officials are encouraged because no new fertile Medflies have been trapped in more than two weeks, said Isi Siddiqui, assistant director of the state Department of Food and Agriculture. Siddiqui said, however, that the next six weeks “are critical” because of the warming weather and ripening back-yard fruit like peaches and nectarines, which are sweet magnets for fruit flies.

“Trapping will be the key,” Siddiqui said, “to telling us if there are any residual infestations.”

That job falls to inspectors like Lomeli, one of nearly 200 county and state workers keeping tabs on traps over 960 square miles in Los Angeles County alone. Normally, there are five trap sites per square mile. But in infested neighborhoods, the traps are increased to 100 per square mile and are checked at least once a week.

The trapping effort has come under fire from critics, such as UC Davis entomologist James Carey, who say it is impossible to detect small Medfly populations no matter how many traps are deployed.

“I don’t care how good the traps are at attracting flies. You can’t declare an infestation is over simply because you haven’t caught any flies,” said Carey, one of five scientists advising the state’s Medfly eradication effort.

On a recent weekday, Lomeli made 39 stops during his 7 1/2-hour shift to check, repair and replace traps.

Behind the wheel of his white county pickup truck, he zigzagged through East Los Angeles, guided by a map in a three-ring binder that indicated every trap on his route. It also identified the type of fruit tree and whether it was in a back yard or front yard.

There were even notations about the presence of dogs. The trappers, like mail carriers, meter readers and other door-to-door service people, must contend with the unknown in every yard.

“When you’ve been chased by Dobermans and bitten by a turkey, you must be very careful. It goes with the turf,” said Lomeli.

Most days, though, action on the trapper beat is slow and tedious. At most stops, Lomeli inspects at least two traps: a McPhail, which is a small glass jar with a hole in the bottom, and a so-called Jackson trap, a small paper tent with a suspended swab of fabric inside. The swab is soaked in a bright green potion containing a sex lure and an insecticide.

Depending on the sex lure used, various species of fruit flies can be targeted with the Jackson traps, while the borax-laced corn syrup mixture in the bottom of the McPhail traps attracts all flies.

Lomeli, who makes about $17,000 a year, has the inspection drill down pat. At each stop, he empties the gooey brown contents of a week-old McPhail trap into a strainer in the back of his pickup, discarding the black houseflies and being careful to save any flies with a distinctive orange hue. Those are fruit flies, the focus of all the fuss. Using tweezers, he fishes them out and puts them into a vial to be studied later at a laboratory to determine type, sex and fertility.

Lomeli also must watch closely for any fruit flies “planted” in traps by county and state agricultural officials to check whether inspectors are doing their work.

“It’s a game, to see if we are doing our job,” said Lomeli, who has an agriculture degree from a Mexican university.

Lomeli lives in East Los Angeles, within a spray zone. Since January, the helicopters have roared over his house every few weeks, coating the neighborhood with malathion. He said he doesn’t like it, particularly because he has two children and his wife is pregnant.

“But what’s the choice?” he asked as he pulled his truck to the curb to check another trap. “It’s something that must be done or the Medfly will destroy the farmlands.”