Medfly Find in L.A. Stirs Fear of Worse Infestation

A Mediterranean fruit fly has been trapped just south of Hancock Park, an abrupt return to the heart of Los Angeles by an infestation that began near downtown but spread mainly through the suburbs of the San Fernando and San Gabriel valleys.

The discovery, made last Thursday but announced on Tuesday, heightened suspicions among some scientists involved in the eradication campaign that the infestation may be far broader than previously thought. And they expressed fears of matters growing worse as the summer approaches.

The immature female Medfly was trapped at a home on Norton Avenue, four miles from where the first Medfly of the current infestation was found nine months ago in Elysian Park.

State agriculture officials Tuesday ordered more trapping to determine if the fly is an isolated find or the first sign of wider infestation. Isi Siddiqui, assistant director of the state Department of Food and Agriculture, said no decision has been made on whether aerial malathion spraying would be ordered for the neighborhood.

The state has said it wants all spraying concluded by May 9.

The announcement of the latest Medfly discovery came as agriculture officials delivered more bad news on the Medfly front: The San Bernardino County community of Upland will be sprayed with malathion on April 20.

The order came after the discovery there a week ago of an immature female Medfly. A 14-square-mile section of Upland will be sprayed once and then sterile Medflies will be released.

Siddiqui said he remains optimistic that the current eradication program is succeeding because no new flies have been found in areas that have been sprayed over the past few months with malathion.

“I’m still confident that we have a handle on this infestation,” Siddiqui said. “We’ve said all along that we would probably find some more flies. I’m encouraged that we’ve not found them in any treatment area.”

The discovery of a Medfly near Hancock Park--about two blocks from Mayor Tom Bradley’s home --is the latest in a series that have popped up with the warm spring weather.

From Feb. 13 to March 20, not a single Medfly was found in Southern California. In the past three weeks, six have been found in communities as far away as Woodcrest in Riverside County and the city of San Bernardino.

While the actual number of flies is small, scientists say that the discoveries are significant because they represent several thousand more flies that have managed to elude the state’s leaky trapping network.

James R. Carey, one of five entomologists serving the state’s Medfly Science Advisory Panel, said the latest discovery is particularly significant because of its proximity to the Elysian Park infestation last year and another Medfly find eight years ago, which occurred just blocks away from the latest discovery.

Carey said the discovery near Hancock Park bolsters his argument that aerial malathion spraying has never eradicated the pest, which he argues has become well-established in Southern California. Carey contends that malathion spraying only knocks down the Medfly population to levels that cannot be detected by the state’s fly traps.

He maintains that the continual reappearance of the pest in the same localities backs up his claim that the pest is not brought in by immigrants or tourists--as other experts believe--but instead has survived for years at low levels, flaring occasionally to where they can be detected.

Carey has maintained that sections of West Los Angeles and the San Fernando Valley are vulnerable to an infestation this year because they have been infested in the past, but have not been sprayed for years.

State agriculture officials counter that the infestations in the Los Angeles area are separated by such long periods--as many as eight years in some cases--that even a small population could not elude detection.

Some critics of Carey’s thesis conceded Tuesday that the latest find near Hancock Park is damaging evidence against the state’s position.

“Of course this gives more support to him (Carey),” said science panel Chairman Roy Cunningham. “But it’s not like we’re ready to say the entire L.A. Basin is infested.”

Richard Rice, another entomologist on the science panel, said the timing of the Medfly discoveries during the past three weeks also is disturbing.

All six flies have been immature females. “These are the emerging adults that made it over the winter,” Rice said. “Some of them are going to mate and they are going to lay eggs.”

Rice predicted the “big surge” of the spring generation’s offspring will appear in June and early July.

Nearly a decade ago, during the Medfly infestation in Northern California--still the largest in the state’s history--a smattering of flies were found in April, leading agriculture officials to believe they were winning the war against the pest, Rice said.

Then, the fly population exploded in June and July.

“This is almost a carbon copy of 1981. It’s right on schedule,” Rice said. “I don’t like it at all.”

Siddiqui countered that unlike the 1981 infestation, the state has been far more aggressive from the outset in using aerial malathion spraying to eradicate the Medfly.

He added, however, that given the unpredictable nature of the pest, it is impossible to guarantee that the Medfly population will not explode in the summer.

“Only time will tell,” he said.

Times staff writer Stephanie Chavez contributed to this story.

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