International effort launched to fight citrus disease threat

An international coalition of citrus farming and agriculture officials is launching a cross-border plan to suppress the march of a tiny insect that threatens California’s $1.6-billion citrus industry. The insect often carries a disease that kills citrus trees and has ravaged orchards in Florida as well as overseas.

After a series of meetings this week in Monterrey, Mexico, the coalition said Friday that the nations had agreed to work together to develop strategies to hold down the population of the insect, impose quarantines on the movements of plants and conduct more tests to see how the disease is spreading.

In addition to the U.S. and Mexico, others participating in the plan include Belize, Costa Rica, the Dominican Republic, El Salvador, Guatemala, Nicaragua and Panama.

They are trying to limit the spread of the Asian citrus psyllid, which is starting to populate Southern California. The insect often is a carrier of citrus greening disease, also called Huanglongbing, or HLB. So far, the nearest outbreaks of citrus greening have been in Louisiana and Mexico’s Yucatan peninsula.

“HLB is like a wildfire with unlimited fuel, and all of our respective countries have to be prepared for when the wind starts blowing in our direction,” said Jim Cranney, president of the California Citrus Quality Council in Auburn. “We are sharing information within this group and learning from each other in the process.”

In August, citrus greening disease was discovered in six citrus trees in the Yucatan peninsula city of El Cuyo. In July, officials found a psyllid that carried the disease in Belize, several hundred miles to the south.

Cranney said the psyllid is present in large numbers in Mexico and could spread HLB quickly unless steps are taken to control its progress. The plan agreed to at the meeting is designed to prevent that scenario, he said.

“Mexico is a critical battlefield for fighting HLB,” Cranney said. He believes the disease is working its way toward the heart of Mexico’s commercial citrus-producing regions in Veracruz.

“By helping Mexico and others, we are helping ourselves. HLB is a death sentence delivered by the Asian citrus psyllid,” he said.

A pilot program in Tijuana that traps for the psyllid and then applies pesticides to the neighboring trees in an attempt to knock down the population is part of the effort by the coalition, Cranney said.

“We also will be working with Mexico on research projects on how to better control the spread of the insect. The research will focus on areas with the same climate conditions that exist in California’s citrus-growing regions,” he said.

The group is also stepping up testing of psyllids in Mexico to see whether they are carriers of the disease.

“Each of the respective countries are looking at their budgets and assessing where there are gaps. Mexico, for example, is helping to fund what’s going on in Belize, and the program in Tijuana is being paid for by the U.S. Department of Agriculture,” Cranney said.

Over the last year, California has developed its own population of psyllids that migrated from Mexico, but none so far has proved to carry citrus greening. However, if the bugs feed on an infected tree, they probably would spread the disease around the state, agriculture officials said.

So far, officials have trapped uninfected psyllids in Los Angeles, Orange, Imperial and San Diego counties. Entomologists expect the bug to make its way up to the prime citrus-growing regions of Ventura, Kern, Tulare and Fresno counties over the next year or two. They say it’s only a matter of time before the Huanglongbing disease finds its way to California from Mexico or elsewhere.

In July, the California Department of Food and Agriculture said that a detection dog working with inspectors at a FedEx depot in Fresno discovered luggage that contained curry leaves shipped from India. The leaves were infested with juvenile psyllids that were carriers of the disease. The insects were destroyed.

The disease does not affect humans, but it does ruin the taste of citrus fruit and juice before killing the plants. There is no known cure.

Most experts believe the first spotting of the disease will be on a backyard tree rather than a commercial orange grove. That’s why they are urging homeowners to learn what to look for at www.california citrusthreat.orgor by calling the California Department of Food and Agriculture hotline at (800) 491-1899.

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jerry.hirsch@latimes.com

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