Quest for New Pest : 9 Peach Fruit Flies Turn Up in Fountain Valley Area on Heels of the Medfly, but They’re Easier to Deal With

When a state agriculture worker knocked on the door of Debbie Neubert’s goblin-decorated home in Fountain Valley this week to tell her about the latest fruit fly alert, her first thought was: The Medfly is back.

Not exactly. But Orange County does have a new fly problem. This time, it’s called the peach fruit fly, imported from India and Southeast Asia. On Wednesday, state agriculture officials confirmed the discovery of the ninth peach fly in a week in a one-square-mile area near the intersection of Ward Street and Warner Avenue in Fountain Valley.

Moving quickly to control the spread of the new pest, state agriculture crews this week began squirting five-milliliter globs of a pesticide-bait mix on trees and telephone poles around the finds, setting up several hundred traps and slicing open fruit to check for peach fly larvae.

And on Wednesday, the state proposed a fruit quarantine in a 75-square-mile area that surrounds the neighborhood where the flies were found.

This is only the third infestation of the peach fruit fly known in the Western Hemisphere, state agriculture officials said. The other two were also in Southern California, near Los Angeles International Airport in 1984 and again in 1987, and both were controlled without crop damage, officials said.

Still, with Southern California just ending a year-long battle with the Mediterranean fruit fly, the Fountain Valley outbreak has state and local agriculture officials on their guard.

“If this things spreads, it would certainly be a major problem to area agriculture, so you have to take it seriously,” said UC Davis entomologist James Carey, who sits on the state’s Medfly Scientific Advisory Panel and studied the peach fruit fly in Pakistan two years ago.

“Two or three (fly finds), you can say maybe it’s isolated,” he said. “But nine certainly gets your attention. There’s definitely something there that has to be addressed, and the state appears to be doing that.”

The fruit fly could damage the county’s Valencia oranges, which produced a $14-million crop last year; tomatoes, valued at $5.8 million; lemons, worth $4 million, and the $1.4-million cucumber crop, according to county Agriculture Commissioner James Harnett.

“We don’t know that much about the peach fly yet,” Harnett said. “But we do know we can’t live with it.”

Among other hosts to the pest, state officials say, are all citrus fruits, apricots, apples, guava, loquats, mangoes, eggplant, pears and the fly’s namesake--peaches.

The peach fly, a cousin to the Medfly, is reddish-brown in color and up to 6 millimeters in length. It multiplies quickly and is a strong flier--able to travel up to 25 miles at a time--making it more difficult for eradication efforts to keep pace.

But in comparison to the recent Medfly battle, state agriculture officials say they have two key factors working on their side.

First, while the Medfly preys on more than 260 varieties of fruits and vegetables, the peach fly is thought to be far more selective, attracted to perhaps only one or two dozen types of produce, state officials say.

Also, while the Medfly’s stubbornness prompted the state last year to embark on its unpopular aerial malathion-spraying campaign, officials assert that the peach fly is easier to eradicate, as demonstrated in 1984 and 1987.

In their fight against the peach fly, state officials are employing a tactic called “male annihilation,” by applying a pesticide mixture that will lure the males and destroy them.

Placed on trees along the street and telephone poles at a height of eight feet, the mixture contains the highly toxic pesticide called Dibrom, which is used commercially, state agricultural spokeswoman Gera Curry said.

State officials say the low levels and out-of-the-way applications in use in Fountain Valley make it safe. But in extremely large doses, Dibrom has been known to cause blurred vision, burning of the skin and numbness.

Curry said this $50,000 eradication effort is expected to last eight weeks--or about four life cycles of the fly. In the meantime, agriculture workers will be checking the traps placed in the area and will continue taking samples of produce to look for larvae.

“We don’t want the thing established here, but our good fortune is that this one can be (destroyed) quickly and quietly and unobtrusively,” Curry said. “If people weren’t told we were here, they wouldn’t even notice.”

The area where the nine peach flies were found is just south of a 36-square-mile spray region that was treated with malathion earlier this year.

The Fountain Valley neighborhood was also part of a quarantine put in place last year as part of the Medfly campaign. But state officials believe that despite that earlier ban, the peach fly was probably brought into this country in fruit through either the mail or air travel.

Quarantines are a first-line defense against a variety of pests.

In response to the peach fly outbreak, state officials plan to impose a 75-square-mile quarantine that would include parts of Fountain Valley, Huntington Beach, Westminster, Garden Grove, Santa Ana and Costa Mesa, and smaller portions of Newport Beach and Orange.

The quarantine would prohibit the transportation of any produce known to be a host to the peach fruit fly. But a decision on the request is not expected for another two weeks.

Curry and Harnett said malathion treatments are not an option for combatting the peach fly. Still, residents of the area seemed wary. They said Wednesday that state workers who came to their houses this week, distributing pamphlets and warning against transporting fruit, did not mention the applications of the pesticide.

“I guess they have to do it,” said Bob Fierro, a 37-year resident of Calle Madero. “But I don’t know. I don’t think this peach fly is that big of a deal, to be honest. And I worry that later on they’ll find out this pesticide stuff is cancerous.”

PEACH FRUIT FLY (DACUS ZONATUS) Description: Reddish-brown with yellowish abdominal cross bands. Transparent wings with small brown spot on each wing tip. Adults are 5 to 6 millimeters, slightly larger than the Mediterranean Fruit Fly.

Hosts: Peaches, pears, figs, citrus, apples, guava, loquats, mangoes, pomegranates, persimmons, tomatoes and cucumbers.

Eggs: White, 1.1 .2 millimeters. Larvae are creamy white, grow to be 7 to 10 millimeters long and do not have legs. Females can lay up to 564 eggs in a lifetime.

Where found: Generally in India, Egypt, Myanmar, Pakistan, the Philippines and most of Southeast Asia, including Laos and Vietnam.

Sightings: There have been two previous sightings (most recently in 1987) in the Western Hemisphere, both in El Segundo, near Los Angeles International Airport.

Proposed quarantine would affect: Fountain Valley, parts of Huntington Beach, Westminster, Garden Grove, Santa Ana, Costa Mesa and small portions of Newport Beach and Orange. Individuals may not move produce that is a known host of peach fruit fly into, out of or within the quarantine area. Commercial fruit must be treated and approved by the county agricultural commissioner before movement is permitted.