Fruit Quarantine Expanded in Medfly War : Infestation: Sterile males are also being released in the South Bay following discovery of a pregnant fly in Wilmington.

State officials this week expanded a quarantine on home-grown fruit and vegetables and started releasing sterile male Mediterranean fruit flies in the South Bay, broadening a pest-control effort that began with the discovery last month of a pregnant fruit fly in Wilmington.

The quarantine area this week grew by 100 square miles, expanding to 1,110 square miles in Los Angeles, Orange and San Bernardino counties. Cities within the newly added zone include Wilmington, Carson, San Pedro and parts of the Palos Verdes Peninsula.

“The female (fruit fly) has a little appendage that she sticks under the skin of the fruit to lay her eggs,” said Carl DeWing, a spokesman for the state Department of Food and Agriculture. “To the average person, the fruit may look perfectly good. But if they move it out of the area, it could start another point of infestation.”

Agricultural officials face a quickly growing infestation that threatens to become one of the largest in Southern California’s history. State officials placed a record 1,300 square miles under quarantine during a massive infestation in 1989-90.

*

The quarantine prohibits the transport of home-grown fruits and vegetables within or out of the area unless they are frozen, cooked or canned. To dispose of excess fruit or vegetables, residents are asked to place them in double-lined plastic trash bags tied at the top.

Quarantine violators face fines ranging from $75 to $1,000.

State officials decided to expand the quarantine area after finding a pregnant female fly in a trap Nov. 29, near Avalon Boulevard and M Street in Wilmington. A week later, authorities sprayed the pesticide malathion within 200 meters of the find. No more sprayings are planned for the area, said MyrlysL. Hollis, a spokeswoman for the food and agriculture department.

Spraying, however, is scheduled to begin today in Compton and Hollywood, where officials found two more pregnant females in traps over the weekend. Authorities expect to spray in those communities at least two more times over the next month. Residents who do not want to be exposed to the pesticide may request an exemption.

Because of controversy over aerial pesticide spraying, state authorities now rely on ground spraying and the release of sterile Medflies to combat infestations of the pests. Although radioactively sterilized Medflies have been used for more than a decade, some scientists believe the technique is ineffective with this species of fly.

The idea is to saturate an infested area with sterilized males in the hope that they will mate with wild females, who would then produce no offspring. Some scientists say that although the method has been successful in combatting a variety of other pests, sterilized male Medflies are too weak to compete for wild female Medflies.

*

State authorities, however, have continued to promote the technique throughout the current outbreak, which began last year. Every week, state workers release 500 million sterile Medflies throughout Los Angeles, Orange and San Bernardino counties.

This week, state workers added a 6.5-square-mile area that includes part of Wilmington to the list of places that receive sterilized flies. State authorities expect to release 7 million sterile flies a week in that area for the next 10 to 12 months.

“There’s going to be a noticeable increase in the number of flies . . . but there’s no harm,” Hollis said. “The sterile flies are not a threat to home-grown fruit or plants.”

Medfly Crackdown

The California Department of Food and Agriculture this week expanded its quarantine on the movement of home-grown fruits and vegetables to a 100-square-mile zone that includes Wilmington, Carson, San Pedro and parts of the Palos Verdes Peninsula.