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Agricultural Officials Declare War on Oriental Fruit Fly

Times Staff Writer

Agriculture officials have launched an all-out battle against a stubborn infestation of the Oriental fruit fly, recommending that a 90-square-mile section of Long Beach and western Orange County be declared a quarantine area.

Authorities have also started using an insecticide bait to kill the insects over a smaller, 13-square-mile area that has been at the center of the invasion.

Since the first Oriental fruit fly was discovered in Long Beach on Sept. 9, county agriculture officials have trapped 38 of the insects. Like the Mexican and Mediterranean fruit flies, Oriental fruit flies pose a serious threat to citrus crops. The flies burrow under the skin of fruit and lay eggs that develop into wormlike maggots, making the fruit inedible.

Restrictions on Produce

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The proposed quarantine would restrict transportation of fruit and soft produce from agricultural fields, nurseries and backyard gardens, but should cause few problems because of the dearth of commercial farmland in the area, officials say. It would not prohibit consumer produce from being brought to grocery stores in the area.

In addition, notices would be mailed to homeowners advising them not to remove any fruit they purchase or grow from the quarantine zone, which would stretch from Long Beach north to Bellflower and includes 30 square miles along the western edge of Orange County.

The quarantine was recommended Tuesday after a meeting of agriculture officials from Los Angeles and Orange counties, the state Department of Food and Agriculture and the U.S. Department of Agriculture. Officials expect the quarantine to be formally declared sometime next week. The recommendation first goes to the director of the State Department of Food and Agriculture and then is reviewed by the state Office of Administrative Law. The quarantine would go into effect when it is filed with the Secretary of State.

Agriculture experts say the infestation is one of the worst to hit Los Angeles or Orange counties. The largest occurred last year, when 92 Oriental fruit flies were found over a 120-square-mile area, with the South Bay region and Westchester hardest hit.

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“This is significant,” said Bob Atkins, pest detection supervisor with the county Agricultural Commissioner’s office. “It’s a substantial infestation.”

While a large number of flies have been discovered, the outbreak has been limited to a relatively small area. That gives agricultural officials cause for hope that the infestation can be stamped out quickly.

“It looks like a fair-sized infestation, but it is staying localized, which is nice,” said Rebecca Jones, an associate economic entomologist with the state Department of Food and Agriculture.

After the first flies were discovered in the Los Altos area of Long Beach last week, agriculture officials instigated a spraying program over a 10-square-mile area. On Tuesday, officials expanded the spraying zone to 13 square miles to include a slice of land near Colorado Lagoon where flies were found late last week.

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Poles, Trees Sprayed

The eradication program began on Friday with state and county workers in a truck squirting one-tenth of an ounce of chemical bait on curb-side utility poles and trees at a height of about 10 feet. About 8,000 poles and trees will be sprayed along each street in the treatment zone.

The mix dries into a bleached orange spot. When the male flies tread on the mixture, it sticks to their feet and is later ingested when they feed. The entire treatment area is to be sprayed in two-week intervals at least three more times, Atkins said.

Atkins said the solution is squirted high enough that it is out of human reach and does not pose a health problem to the public. About 10% of the mix is the insecticide Diabrom, the other 90% is a lure that attracts male flies. By killing the male flies, the reproductive cycle of the pest is interrupted.

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In recent years, government officials have used aerial spraying of the pesticide malathion to battle outbreaks of Mediterranean and Mexican flies, an effort that proved effective but prompted protests from residents worried about possible health hazards.

Aerial Spraying Unforeseen

Atkins stressed, however, that officials are not contemplating the use of aerial spraying. The use of ground spraying, while not very effective against Mediterranean or Mexican fruit flies, has proven successful in battling the Oriental strain, he said.

Concern about the outbreak comes in large part because the Oriental fruit fly, which is slightly larger than a common housefly and usually yellow in color, can travel great distances and spread rapidly.

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While there is little commercial agriculture in the proposed quarantine area, officials are concerned that the flies could use Long Beach as a staging area for an assault on fruit and vegetable growing regions in Ventura, San Diego and Orange counties.

And if the flies spread far enough, the outbreak could potentially infest the San Joaquin Valley, posing a threat to the state’s multibillion-dollar agriculture industry.

Danger to San Joaquin Valley

“Once it got a foothold in the agriculture areas, it’d be history,” Atkins said.

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Jones said state officials have estimated that the California agriculture industry would lose more than $170 million a year if the Oriental fruit fly infested crops statewide.

To more closely monitor the movements of the flies, agriculture officials have boosted the number of traps in the proposed quarantine area, Atkins said. By doing that, officials hope to provide a sufficient buffer zone to keep the flies from leapfrogging to new areas, he said.

Besides finding the flies, agriculture inspectors have discovered maggot-infested vegetables and fruit at three different areas in the treatment zone.

At one site, a piece of fruit from an apple tree was found to be riddled with maggots. The tree, located behind a house near Palo Verde Avenue and the San Diego Freeway, was stripped of its fruit, which has been fumigated, placed in plastic bags and buried. A similar procedure was followed at the other sites.

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Flies Emerge From Ground

When officials find infected fruit or vegetables, they also treat the ground around the tree or plant with an insecticide to kill any maggots that might have burrowed into the soil. After an infested piece of fruit falls to the ground, the maggots enter the soil and form a cocoon, emerging several days later as flies.

Agriculture officials are unsure how the outbreak began in Long Beach, but feel it probably was sparked by someone bringing an uninspected piece of fruit into Long Beach from Hawaii, Southeast Asia or some other area infested with Oriental fruit flies.

The agricultural commissioner’s office maintains more than 5,000 traps throughout the county to determine the presence of Oriental or Mediterranean fruit flies and other winged pests.

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In July, a single Oriental fruit fly was found in one of the county’s traps in the Mt. Washington area of Los Angeles. Another fly was discovered in Burbank and a third on the Palos Verdes Peninsula in August. Since no other flies were found in those areas, agriculture officials decided not to begin any spraying program.

The only commercial agriculture in the proposed quarantine zone is a tomato field located on leased land at the Seal Beach Naval Weapons Station and a field of cucumbers near the Los Alamitos race track, Atkins said.

He said the tomatoes are set to be processed and will not be affected by the proposed quarantine because they will be cooked, which destroys any fly larva. The cucumbers might have to be destroyed unless they can be processed as pickles, he said.


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