Residential Areas Added to Medfly Control Zone : Quarantine: The expanded program primarily affects Brea-Yorba Linda and the county’s border with Long Beach. Sterile flies will be released in March.

The quarantined area for the Mediterranean fruit fly has been expanded to include another 300 square miles, about 100 of which are in mostly residential areas of Orange County, officials said Wednesday.

*

The new quarantine here primarily affects the Brea-Yorba Linda area and the Orange County-Long Beach border. The expanded area also includes parts of Los Angeles, Riverside and San Bernardino counties.

For Orange County, “a good portion of the area (newly quarantined) is residential, with some back-yard farmers, people who grow fruits and vegetables in their back yard and sell them to neighbors, farmers markets, those kind of things,” said John Ellis, deputy agricultural commissioner of Orange County. “The new area is going to include a few more growers, but in many cases they will have some time to prepare for the new requirements, because their crops are not ripe yet.”

But “they are going to have to regulate the products that they are growing if those crops are hosts to Medflies, or they may choose alternate crops that aren’t hosts,” he said.

In Orange County, where agriculture is a quarter-billion-dollar industry annually, Medflies have been detected in Westminster, Santa Ana, Anaheim, Orange and Yorba Linda, said Larry Hawkins, spokesman for the Cooperative Medfly Project, a joint county and state effort to eradicate Medflies. But that “does not mean that there are millions of (them) there,” he said.

The expanded quarantine area, which went into effect Friday, now includes 1,576 square miles in Southern California. A total of 307 are in Orange County, including Anaheim, Orange, Santa Ana, Westminster, Brea and Yorba Linda.

The quarantined area was established by the state Department of Food and Agriculture in July in an effort to stop the infestation of the pests that broke out in Granada Hills last year. Fruits grown in the quarantined area may not leave unless they are processed (cooked, canned or frozen, for example) or treated with appropriate pesticides. Growers must comply or face a fine, said Carl DeWing, a state agriculture spokesman.

*

Quarantined areas will also be inundated with more sterile flies starting March 1. This was also done last fall in Westminster and Santa Ana, and later in Yorba Linda, Orange and Anaheim. The strategy is that mating between the sterile fly and the Medfly will breed the Medfly out of existence. This will be done for the first time in Brea, because it lies between areas where Medflies have already been spotted, Hawkins said.

“We want to have a large, wide-scale program that ensures we will not have these isolated infestations popping up,” Hawkins said, adding that the sterile fly infestation program will cost about $30 million in 1994.