Oriental Fruit Flies Discovered in 3 Cities : Pest: State workers spray a pesticide mix on tree tops and utility poles. The finds come on the day Medfly quarantine begins.

The new discovery of Oriental fruit flies in three Orange County cities prompted state workers Friday to begin eradication work, a state spokesman said.

Department of Food and Agriculture workers squirted blobs of a pesticide mix on the tops of tall trees and utility poles to attract and kill male Oriental fruit flies.

State spokesman Carl DeWing said seven Oriental fruit flies had been discovered in Buena Park, Anaheim and Santa Ana on Wednesday.

Ironically, on the same day state agriculture officials quarantined a 65-square-mile of Orange County where dozens of Medflies had been found.

That quarantine affects the cities of Garden Grove, Westminster, Huntington Beach, Fountain Valley, Santa Ana, and Costa Mesa. Residents in the affected area cannot move fresh, home-grown fruit or vegetables from their property unless they have first processed it some way such as cooking, freezing or canning.

But DeWing said the state agency was not as concerned about the Oriental fruit fly as they are about the Mediterranean fruit fly, which is more difficult to control.

“With the Oriental fruit fly, we’ve been able to develop a pheromone that we mix with a pesticide,” DeWing said. “It serves as male annihilation and then the females do not have anyone to mate with and they die off too.”

The Oriental fruit fly, or Bactrocera dorsalis , is slightly larger than a housefly and is identifiable by its yellow legs, experts said. It is far less costly to eradicate than the Medfly because the males can be easily duped with an insecticide-laden bait. Medfly eradication, however, often requires aerial spraying, DeWing said.

The Oriental fruit flies were found in traps on Monroe Avenue in southeast Buena Park and northwest Anaheim, Del Monte Drive in Buena Park, and Sullivan Street in Santa Ana.

A state spokeswoman said a male peach fly was identified Friday in Anaheim, near the intersection of Colchester Drive and Harvest Lane.

State workers will set more traps to see if there are more peach flies, said Myrlys Hollis , a state spokeswoman.

“Basically, we spray bait and insecticide with a device like a water gun,” she said. “And we eradicate the peach flies, the same way as Oriental fruit flies by male annihilation.”