Citrus greening disease has been found in Mexico, a discovery long feared by California’s citrus industry.


Senasica, Mexico’s counterpart to the Plant Protection and Guarantine program under the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, confirmed that the bacterial disease — huanglongbing, also known as HLB —was found in six trees on the Yucatan Peninsula, said Bob Blakely, director of grower services for California Citrus Mutual, Exeter.


“Mexico has been very cooperative in fighting the Asian citrus psyllid and HLB,” Blakely said Aug. 18. “We have another meeting next month to further develop the strategic plan for our cooperative effort against HLB.”


The insect was discovered for the first time on North America’s West Coast in June 2008, in traps in and around Tijuana, Mexico. More of the pests were later trapped north of the border in San Diego and Imperial counties.


“Both the USDA and Mexican officials continue the search for the psyllid and are treating areas along the U.S.-Mexico border from the Pacific to Arizona,” Blakely said.


Late summer is when the trees are at the peak of what the industry calls a flush, when the trees flush out with new growth.


“That’s what the psyllids like to feed on,” Blakely said. “This is a time we really want to increase our vigilance, because it’s when they’re most active.”


The major fear of the industry and researchers is that HLB is already in California, having arrived in landscaping and nursery stock shipped from Florida. A particular suspect, Blakely said, is the orange jasmine, which is a very popular ornamental that is a carrier of HLB; it is very prolific in Florida.


There could be hundreds or thousands of the trees in Southern California.


“If it’s sitting in someone’s backyard down in L.A. County, and there are no psyllids to move it around, it just sits there as a repository,” Blakely said. “All it takes is for one psyllid to feed on that tree, and the disease starts to spread.”


The confirmation of the disease in Mexico should ring a warning bell to California citrus growers and homeowners with citrus trees in their yards, Ted Batkin, president of the California Citrus Research Board, Visalia, said in a news release.


“It’s like Mary’s little lamb,” Batkin said in the release. “Everywhere the pest goes, the disease is sure to follow. The only way to save California citrus is to control the psyllids, and the public plays a critical role in that process.”


Many of the psyllid finds in California have been the result of a homeowner’s inspecting his trees, Batkin said.

HLB has forced Florida growers to destroy or abandon 200,000 acres of citrus groves, according to the state’s 2008 tree census. The 2009 census is to be released in September.

In California, citrus is a $1.6 billion industry.