War on Fruit Fly to Begin Friday in Central County

California’s war on the crop-destroying guava fruit fly, which made its first appearance in the Western Hemisphere in three Orange County backyards last week, will begin Friday, state agriculture officials announced Wednesday.

Armed with federal permits that were granted Wednesday, state entomologists will be treating utility poles, trees and even fence posts over a 16-square-mile area of central Orange County with a sticky paste designed to lure male guava flies and a pesticide that will kill them, hopefully before they have impregnated female flies.

“If we have to have an eradication program, we’re fortunate that the (guava) fly can be treated with this ‘male annihilation’ technique,” said Gera Curry, spokeswoman for the state Department of Food and Agriculture, which is conducting trapping and eradication efforts.

“We’re fortunate because it’s a technique that is safe for the public, unobtrusive and effective,” Curry said Wednesday.

Three specimens of the guava fruit fly-- Dacus correctus-- were trapped last week in Garden Grove, Westminster and Midway City. It is the first trace of the fruit fly, which is native to India and Asia, on this side of the Pacific Ocean, agriculture officials said.

Intensified Trapping

No more flies have been found since Saturday despite intensified trapping efforts in the surrounding areas, but the attack is being launched immediately in hopes of eradicating the fly before it spreads, said state entomologist Brian Taylor, who will oversee the project.

The fly is considered a menace to citrus, peach, guava and mango crops in its native range in India, Sri Lanka, Pakistan and Thailand. It also has spread to the Philippines and Japan.

Agriculture officials in Sacramento say they do not believe the fly, which is thought to have come from tropical fruit mailed illegally to California, presents as big a threat to California agriculture as the Mediterranean fruit fly did between 1980 and 1982.

Over a 27-month infestation period, the state spent $100 million on eradication efforts against the so-called Medfly, which threatened California’s $14-billion-a-year agricultural industry.

“We learned the hard way in the 1980 Medfly invasion that quick action is required,” Curry said.

Western entomologists, who know little about the guava fruit fly, assume the fly will attack citrus crops and soft, fleshy fruits like peaches, plums and nectarines if it gains a foothold in California. “But there is no telling what else they might decide they like,” Curry said.

Worm-like Maggots

Agriculture officials Wednesday also called upon the public to notify the Orange County Agricultural Commission office in Anaheim if evidence of the guava fly’s white worm-like maggots is found in freshly picked home-grown fruit.

Taylor said the treatment area will include parts of Garden Grove, Fountain Valley, Huntington Beach, Santa Ana, Stanton, Westminster and unincorporated Midway City.

Boundaries, subject to minor modification, are Edinger Avenue on the south, Euclid Street on the east, Orangewood Avenue on the north, and Beach Boulevard and Golden West Street on the west, connected by Trask Avenue.

The so-called “male annihilation” treatment program involves a sticky liquid of methyl eugenol as bait and an insecticide, which is squirted high on tree trunks, utility poles and fences. The bait lures the male guava fruit flies to the paste, where they are trapped. The insecticide, dibrom, kills them, preventing them from reproducing.

The flies have already shown they are attracted to the sex lure, which was used in the original trapping stations. And dibrom has been used successfully to combat Oriental fruit fly infestations, Curry said.

Squirted in Blobs

Taylor said entomologists will cruise the target area in one clearly marked state truck and apply the bait to about 600 poles, posts and trees per square mile with a special spray gun. The gray paste will be squirted in blobs about four inches in diameter at least eight feet above the ground, well out of reach of children and pets.

Wind conditions will be monitored to ensure that the bait does not spread. “There is very little chance of drift, but we don’t want to take any chances,” Taylor said.

Utility companies will be notified of the application sites to prevent injury to line workers who might come in contact with the sticky material.

Taylor said a two-man team will work through the weekend to cover the area surrounding each of the three sites where guava fruit flies have been found. He said treatment of the remaining area should be completed within 10 days. After that, reapplication is required every two weeks.

Taylor said the eradication program will last “a minimum of four treatments . . . after the last fruit fly is found.”

Thousands of Traps

The first fly was found Aug. 6 in a backyard peach tree in the 9000 block of Larson Avenue in Garden Grove. The tree contained one of the thousands of insect traps maintained and regularly inspected by the state since the Medfly infestation.

That find prompted agriculture officials to place 50 more traps in the surrounding square mile. On Saturday, two more guava fruit flies were discovered in new traps in another peach tree in the 14000 block of Shirley Street in Westminster, and in a grapefruit tree in the 14000 block of Wilson Street in Midway City.

One-square-mile areas surrounding both sites have been saturated with 100 more traps, but Taylor said no more flies have been found in any of the traps, which are checked daiy.

Additional traps--five per square mile in 81 square miles around Westminster--have been set to determine the extent of the infestation.

No sign of the pest has been found anywhere else in California.