Discovery of Oriental Fruit Flies Prompts Pasadena-Area Spraying

The state Department of Food and Agriculture has begun spraying small globs of insecticide on light poles, trees and telephone poles over 9 square miles in the Pasadena area after the discovery of two Oriental fruit flies this week.

The flies, which pose a threat to the state’s multibillion-dollar agriculture industry, were discovered Wednesday and Thursday in fly traps set up in a monitoring area in southwest Pasadena. Inspectors had been monitoring the area since the discovery of a fruit fly Oct. 20.

The spraying began Friday morning and will continue through Sunday, said Bob Atkins, pest prevention supervisor for the county agricultural commissioner’s office.

Atkins said the state Department of Food and Agriculture will probably treat the area three more times during the next three months.

Treatment Process

Unlike the Mediterranean fruit fly, the Oriental variety is easily controlled, Atkins said.

The treatment process, which only begins after two or more flies are found, involves using a chemical called methyleugenol, which attracts male fruit flies. The chemical is laced with an insecticide.

A small amount of the chemical is being squirted six to eight feet above the ground on poles and trees in 600 locations in each square mile of the area, which covers parts of Pasadena, South Pasadena and San Marino.

The treatment area is roughly bounded by Orange Grove Boulevard on the north, Hill Avenue on the East, Huntington Drive on the south and Fair Oaks Avenue on the west.

If five or more Oriental fruit flies are found, Atkins said the area will be quarantined, banning removal of fruit.

“We don’t anticipate any problems, certainly nothing as drastic as with the Mediterranean fruit fly,” Atkins said. “We have a tremendously powerful attractant. Without males you just have a lot of lonely females left.”

Fourth Outbreak

The Pasadena outbreak is the fourth fruit fly infestation in the county this year.

Mediterranean fruit flies were found in West Los Angeles and the San Fernando Valley in July. Both infestations required aerial spraying and the release of millions of sterile Medflies to break the reproductive chain.

Atkins said the eradication effort in the Valley is expected to be completed in mid-November. But treatment on the Westside has not been as successful and will probably continue until spring, he said.

The fourth outbreak, which involved Oriental fruit flies, occurred in Hacienda Heights in October. Treatment in a 9-square-mile area is expected to be completed in three months.