Even before the first drops of malathion fell over parts of the San Fernando Valley on Monday night to fight the county's worst Mediterranean fruit fly infestation, officials reported finding more of the crop-destroying pests, requiring aerial spraying of a new area of the San Gabriel Valley.
In the latest infestation--the county's fifth this year--spraying was ordered for Thursday night over 12 square miles encompassing Rosemead and South El Monte, where two Medflies were found over the weekend.
That brought to 131 the number of Medflies found in the county this year, according to officials. They have ordered aerial spraying of a total of 75 square miles for all five infestations and released more than 100-million sterile flies to breed the insect out of existence.
So far, the unprecedented number of infestations has caused no major problems for the state's billion-dollar agricultural industry because the vast majority of the state's produce is grown outside the county, a California Farm Bureau spokesman said.
But officials said they are worried about other countries, especially Japan, placing California produce under quarantine.
"It's getting real ticklish," Deputy County Agricultural Commissioner Bob Atkins said. "The Japanese are looking very warily at what we're doing."
"The most serious threat to agriculture is the possibility of foreign quarantine," said David Keim, plant protection and quarantine officer for the U.S. Department of Agriculture.
Although a large part of the county is under quarantine--prohibiting the removal of locally grown fruit and vegetables from infested areas--crops from growing areas to the north can be transported through infested areas to the downtown Los Angeles produce market in covered trucks or at night when the pest is inactive.
"We're very nervous," the Farm Bureau spokesman said. "Every time we have an infestation, it creates the opportunity for the pests to get out into some of the agricultural areas of California."
Asked for comment on the latest find, Susan Trowbridge, a press spokeswoman for Gov. George Deukmejian, said, "We never like to see Medflies. We will do all that we can as quickly as we can to take care of the problem. The Department of Food and Agriculture is monitoring the situation and will take necessary action to eliminate the Medflies as soon as possible."
Medflies lay their eggs in more than 260 varieties of fruits and vegetables, rendering the produce unsalable. The pest is established in Hawaii, parts of Central and South America, southern Europe and Australia.
State and federal scientists blame the regions's five infestations on illegally smuggled "dirty fruit,"--citrus contaminated with Medfly eggs or larva.
Scientists say the area's numerous airports, proximity to the Mexican border and large immigrant population provide easy entrance for the pest.
"We feel that the fruit fly problem in L.A. is a people problem. People are the source of these infestations," said Roy Cunningham, of the U.S. Department of Agriculture in Hawaii, one of the nation's leading Medfly entomologists.
Scientists believe that four of the five infestations are independent finds and not the result of natural dispersement. During its lifetime, the Medfly only travels several hundred yards from it birthplace, and it is not possible for the insect to fly throughout Los Angeles on its own.
"I suppose its outright smuggling," Keim said, pointing out that inspectors have confiscated hundreds of pounds of illegally imported moman , a popular fruit in Latin America that is in great demand in Latino neighborhoods in Los Angeles.
Keim said that ports of entry into the United States are "well covered." He pointed out that dogs are stationed at airports to sniff for fruits and vegetables in the suitcases of arriving passengers.
"When people come through the regular ports of entry, we feel we are doing a pretty good job of picking up fruits and vegetables," he said.
State officials plan to begin offering a $10,000 reward, donated by the agriculture industry, for the conviction of a person "who sneaked in fruit and thereby caused an infestation," a state Food and Agriculture spokesman said.
"This is becoming far too frequent," Los Angeles County Agricultural Commissioner Leon Spaugy said. "We have a problem. We have a seeming disregard for the quarantines.
" . . . We always stress the importance of not taking home-grown fruit to Aunt May's or someone else's outside the quarantine area," he said. "But we still have a number of people who--either deliberately or through ignorance--are taking fruit outside the area. And there is always the distinct possibility that it will start an infestation."
Battling the infestation costs between $1 million and $2 million in each area, he said.
Two helicopters loaded with malathion lifted off from Van Nuys Airport at 9 p.m. Monday to begin the valley spraying operation, which was expected to take up to six hours to complete.
In the new area to be sprayed Thursday night, California Conservation Corps members will today begin distributing 100,000 flyers to residents advising of the spraying.
The area to be sprayed is bounded by the Pomona Freeway, Garfield and Santa Anita avenues and Valley Boulevard. The boundaries could be expanded if a fly trapped Monday, just north of the proposed spray zone, is confirmed to be a Medfly, authorities said.