Asian Citrus Psyllid on the West Coast and In-Between
The Asian citrus psyllid has been confirmed in three locations in Tijuana, Mexico, only 1.9 miles from the California border. This comes a few weeks after the psyllid and the citrus greening disease it spreads was confirmed in New Orleans. “It's shocking,” Joel Nelsen, president of California Citrus Mutual, says about the finds in Mexico. The insects were not discovered by the U.S. Department of Agriculture's Asian citrus psyllid trapping program, he says. Instead, they were picked up by a 
general pest trapping program. “It's extremely disconcerting for it to be discovered so close to San Diego County, where there's ample enough host plants,” Nelsen says. “It's created major activity on our part.” Nelsen says the industry is still waiting to hear from the USDA whether the psyllids from Mexico carried the greening bacteria.
The California Department of Food and Agriculture is wrapping up its annual survey for the psyllid and greening and has not detected either pest. Inspectors annually survey about 25 percent of commercial citrus groves, as well as other high-risk areas, such as packinghouses and nurseries, where the pest might enter.
The Louisiana Department of Agriculture and Forestry has an inquisitive New Orleans homeowner to thank for the discovery of the psyllid and citrus greening. She saw an unusual insect on her lime tree and looked it up on the internet. The homeowner then sent a couple of digital images of the pest to a local 
Louisiana State University AgCenter Extension agent, who identified it as an Asian citrus psyllid. The state, working in conjunction with the USDA's Plant Protection and Quarantine (PPQ) division, collected samples of the pest and foliage in late May. The insect identification was confirmed by USDA's facility in Beltsville, MD a few days later, and the USDA confirmed the foliage was positive for citrus greening early in June.
Louisiana and PPQ officials have conducted delimiting surveys within a 1-, 5- and 10-mile radius of the positive tree. In addition, they continue to survey neighboring parishes for the pest and disease. So far, Asian citrus psyllid has been confirmed in Orleans, Jefferson, Plaquemines, and St. Charles parishes.
Of the nearly 90 foliage samples that have been sent to Beltsville, about half have come back negative for citrus greening. Hardy says results on the other samples are pending. The only positive greening samples are from the homeowner's lime tree. The infected lime tree had been in the ground for about three years. Before that, it was in a pot. The homeowner originally received the tree as a gift.
As a result of the insect and disease confirmations, Louisiana state agricultural officials have to consider quarantine options. They're leaning toward an interior quarantine where just the counties positive for greening and psyllid would be regulated. They also would have to conduct an eradication program to rid the areas of the psyllid and greening. If Louisiana officials decide against an interior quarantine and eradication, the USDA could impose a statewide quarantine, much like they have with Florida.
Texas has had the Asian citrus psyllid since 2001, and 37 southern counties remain quarantined. But so far, agricultural officials have not detected citrus greening, says Julian Sauls, a professor and Extension horticulturalist at Texas AgriLife's research station in Weslaco. “We hope that means that the psyllid that came here didn't have the greening bacterium in its system,” Sauls says. “But that's not to say there's a tree somewhere in the state that doesn't have it. We still look every year from here up to Houston, because we don't need [greening].”
Members of Texas Citrus Mutual, Florida Citrus Mutual and California Citrus Mutual recently held a conference and agreed to adopt Florida’s citrus health response plan, Nelsen says. They also agreed that more money needs to be allocated toward the fight. That includes funding for additional dog teams to detect possible contraband being brought into California and more inspections at the Arizona border. In addition, they want money put toward developing faster disease detection tests in California. Members agreed that the Asian citrus psyllid is still confined within Texas, and they hope to seek a permanent psyllid eradication program in that state. (New York Times, 6/10/08).
