Spraying for Medflies Begins Tonight : Quick Action Taken to Curb Infestation North of Downtown

A backyard peach rotted through with larvae of the pesky Mediterranean fruit fly provided further proof Wednesday of an infestation by the crop-destroying insect in neighborhoods north of downtown Los Angeles, county and state officials said.

Identification of the Medfly larvae by a state Department of Food and Agriculture laboratory in Sacramento came as officials were making last-minute preparations for an aerial spraying of malathion tonight over 14 square miles of Los Angeles that include the communities of Elysian Park, Echo Park and Silver Lake.

“Past experience has shown that we have to respond quickly,” said Los Angeles County Agricultural Commissioner Leon Spaugy. County, state and federal officials in the last year have successfully fought off similar Medfly infestations in West Los Angeles and in the San Fernando Valley.

The aerial spraying of a syrupy mixture of the insecticide malathion and a corn syrup base is scheduled to begin at 10 p.m. and last for several hours, officials said. The infested area is bounded roughly by 3rd Street on the south, Los Feliz Boulevard and the Golden State Freeway on the north, Western Avenue on the west and the Harbor and Pasadena freeways on the east.

Warnings Distributed

About 260 California Conservation Corps members on Wednesday distributed the last of 150,000 flyers to residents in the sector to be sprayed. The flyers warn residents to remain indoors during the spraying and to protect their automobiles’ paint with covers.

The flyers advise that spraying will pose no health hazard, saying there is only enough poison in the malathion spray “to kill a fly.”

Despite thoses assurances, some residents said Wednesday that they are worried there may be long-term effects of malathion that are still unknown.

“I don’t feel comfortable having a chemical sprayed down on us from the sky,” said Connie Rohman, a Silver Lake resident who is pregnant.

Rohman’s neighbor, Linda Rescia, said she plans to cover her vegetable garden to protect against the malathion spray.

“It’s a poison,” she said.

Dosage Small

But Dr. Paul Papanek, a physician with the county Department of Health Services, said that the dosage of malathion in the spray mixture is so small, about two ounces an acre, that “someone would have to lick a tenth of an acre” to begin to feel ill effects.

Discovery of the Medfly larvae, which are white maggots that eat the pulp of fruit before growing into adult flies, makes it certain that the Medfly has gained a foothold near downtown, county and state officials said.

Since July 20, three adult Medflies have been found in traps that are hung from fruit trees and checked periodically by county inspectors.

Failure to quickly squelch the Medfly invasion could pose a danger to the state’s multimillion-dollar agriculture business, Spaugy said.

If left unchecked, the flies would multiply and eventually find their way to California farms. The larvae feed on more than 260 varieties of fruit and vegetables and render the produce unsalable, he said.

Sterile Flies

After the aerial spraying, county and state officials said they plan to release 40 million sterile Medflies each week beginning in late August. Officials said they hope that the $1-million effort will eliminate the Medfly by November.

A 70-square-mile area has been declared a Medfly quarantine zone, with residents prohibited from transporting home-grown fruit to other parts of Los Angeles. The quarantine area is bounded approximately by Highland Avenue on the west, the Santa Monica Freeway on the south, Soto Street on the east and the Ventura Freeway and Colorado Boulevard on the north.

Delays by former Gov. Edmund G. Brown Jr. in battling the Medfly during a 1981 infestation in Santa Clara County resulted in about $100 million in crop losses, state officials said. The cost of eradicating the Medfly climbed to about $100 million because of the delays, they said.

ABOUT THE MEDFLY FACTS AND FIGURES * Slightly smaller than a housefly; wings have brown, yellow, black and white markings. * Widespread throughout Australia, Central and South America, Europe and Africa. In the United States the Mediterranean fruit fly is established only in the Hawaiian Islands, where it was discovered in 1910. Because of the Medfly, worldwide quarantine laws were enacted to regulate the entry of fruits into countries. * Has been recorded infesting more than 200 different types of fruits and vegetables. * Threatens many California crops including apricot, avocado, grapefruit, nectarine, orange, peach and cherry. * The female lays eggs in groups of one to six eggs within the fruit. The larvae tunnel inside, feeding on the pulp, and emerge through exit holes in seven to 24 days, often leaving the fruit unfit for human consumption. Decay organisms enter, leaving the interior of the fruit a rotten mass. * The average life span of the adult is about 30 days. Breeding is continuous, with several annual generations. * Estimates say the permanent presence of the Medfly in California would result in yearly losses of more than $205 million in crop damages, additional pesticide use and quarantine requirements. ERADICATION METHODS * Spraying fruits with pesticides, such as malathion, during the egg-laying season. * Destroying already infested fruit. * Control by other parasites. * Introducing sterile Medflies into the fertile population, used only in conjunction with other methods. Sources: Los Angeles Agricultural Commissioner; Encyclopaedia Britannica. Compiled by Times researcher Tracy Thomas