Oceanside Medfly Find Spurs Malathion Effort

Agriculture officials plan to begin small-scale malathion spraying today in Oceanside if the rain clears, after last month’s discovery of two Mediterranean fruit flies.

In a three-pronged attack on the Medfly--considered one of the world’s most destructive insects--officials will setting two types of traps and spray a 33-block area with a mist of insect bait and the pesticide malathion. There are about 500 residential lots in the spraying area.

Meanwhile, quarantine area boundaries are being drawn to prevent the spread of the Medfly via infested plants and produce. The quarantine will probably cover Oceanside and a portion of Carlsbad and last until August, officials from the state Department of Food and Agriculture said Monday.

The Medfly is a threat to agriculture because it bores holes in ripening fruit and lays eggs inside. Maggots hatch and eat the fruit until it rots and falls to the ground. Then the maggots enter the soil, mature into flies, emerge and begin the cycle again.

Medflies attack more than 250 types of fruits, nuts and vegetables, but prefer peaches, pears, plums, apricots and cherries.

San Diego County has a $1-billion-a-year agriculture industry that could be threatened by a Medfly infestation, county Agriculture Commissioner Kathleen Thuner said. However, the trapping of only two flies suggests that Oceanside’s infestation is “fairly limited,” another official said.

In an effort to allay residents’ fears about the malathion spraying, state entomologist Brian J. Taylor said only one to two gallons of the bait and poison mixture will cover the 33-block zone.

“It is really minuscule,” Taylor said. “All we’re doing is killing flies, and it doesn’t take much.”

Nevertheless, officials say they will advise residents to keep their windows shut and pets confined during the spraying, and to wash home-grown produce before eating it.

Hundreds of traps are also being set in the area, including 750 yellow sticky panel traps to lure the bugs. One in every three yards will get such a trap.