An invasive pest that can carry an incurable citrus blight and had been confined to the U.S.-Mexico border region has been found farther north in California, advancing what one expert calls the greatest threat in modern history for the state's $1.6 billion citrus industry.
"We've gone into full battle mode," said Ted Batkin, president of the California-based Citrus Research Board.
Officials confirmed Tuesday that five Asian citrus psyllids were found on a backyard lemon tree in Santa Ana, 100 miles (160 kilometers) north of the U.S.-Mexico border.
The tiny pest can carry the disease huanglongbing, also known as citrus greening, which has ravaged citrus production overseas and in the southeast United States.
Researchers are examining the psyllids to determine if they carried the disease. Excluding psyllids found in a package shipped from overseas, it was the first time the bug has turned up in California farther north than the existing quarantine zone in San Diego and Imperial counties. The pests' presence in Orange County has alarmed industry representatives.
California follows Florida as the second largest citrus-producing state and leads the country in fresh citrus production, according to U.S. Department of Agriculture data. The California industry comprises more than 3,500 growers and 14,000 harvesters, packers and shippers, mostly based in central California's fertile San Joaquin Valley, according to Bob Blakely of the growers' association California Citrus Mutual.
"We're quite disturbed to hear about the find," Blakely said. "If this industry becomes threatened or destroyed, all of our citrus would have to be imported."
The psyllid can contract the disease and pass it along when it feeds on a tree. The disease spoils the flavor of the fruit, discolors leaves and ultimately kills the tree.
"It's a death sentence for a citrus tree," said Steve Lyle, spokesman for state Food and Agriculture. "There is no cure for the disease."
Citrus greening may be the most terrifying threat to California's agriculture industry, but it's not the only one. Globalization and transporting plant material between states have dramatically increased the number of produce-borne infestations in recent years, Batkin said.
Blakely said the growers' association is operating on the assumption that the pathogen is lying dormant elsewhere in California, and the priority is ridding the state of the psyllid that can spread it.
State agriculture authorities will impose a quarantine in the area of Orange County where the psyllids were found. In the meantime, movement of certain plants and plant material at nurseries within five miles of the site is being restricted. Under quarantines, the public is urged to not move produce out of affected areas.
The state is also ramping up efforts to trap and survey in the area.
"Citrus production is a significant component of California agriculture," Lyle said, "and we want to do all we can to protect it."