SACRAMENTO — Despite a couple of recent expansions of the quarantine zone for the Asian citrus psyllid in Tulare County, state and industry officials maintain hope that they’re keeping the pest under control.
The California Department of Food and Agriculture initiated new quarantines this month in a 110-square-mile area near Ivanhoe, Calif., and a 14-square-mile section near Farmersville, Calif., bringing the total quarantine area in Tulare County to 870 square miles.
The expansions come after three psyllids were found in separate traps in the county. State pest control managers hope the finds aren’t signs of an escalated infestation of trees in California’s citrus belt.
“That’s the objective is to be able to get a clear sense of where the bugs are and draw a quarantine around that, and we hope we have it now,” CDFA spokesman Steve Lyle said. “It doesn’t take too much to reach a situation where you have to expand the quarantine. Finding a bug or two is enough to have to expand the quarantine.”
So far, no breeding populations of the psyllid have been found in the Central Valley, said Bob Blakely, California Citrus Mutual’s director of industry relations. He said the latest bugs were probably “hitchhikers” that were on equipment or fruit that came from Southern California.
“That pest is very successful at hitchhiking,” Blakely said. “It’s also possible we have a very low population that’s still kind of elusive, and that’s how they’re showing up in these traps. There’s always something going on. We continue to find them very sporadically in Tulare County.”
The latest areas join other quarantine zones in portions of Tulare, Fresno, Kern and San Luis Obispo counties as well as entire-county quarantines in Imperial, Los Angeles, Orange, Riverside, San Bernardino, San Diego, Santa Barbara and Ventura counties.
Under the quarantine, host nursery stock is prohibited from being shipped except for nursery stock and budwood grown in U.S. Department of Agriculture-approved structures designed to keep the psyllid out. All untreated citrus fruit has to be cleared of leaves and stems prior to moving out of the area.
While the quarantines haven’t prevented growers from getting their fruit harvested or moved, treating orchards has added costs for growers in a season in which crop loads have been significantly diminished in some areas because of a winter freeze.
Growers must apply sprays within seven days of harvest, and doing so costs between $40 and $60 an acre, Blakely said.
Asian citrus psyllids were trapped for the first time in the state’s citrus belt in November 2012, causing the state to initially restrict citrus within a 20-mile radius of the finds before the area was reduced to five miles.
Asian citrus psyllids generally don’t harm fruit, but they can carry the plant disease huanglongbing, which causes citrus greening and eventually kills the trees. The University of Florida estimates the disease has caused more than 6,600 lost jobs, $1.3 billion in lost revenue to growers and $3.6 billion in lost economic activity in Georgia, Louisiana, South Carolina and Texas, where the disease is present, notes a CDFA news release.
“We are continuing to work with the goal of keeping the pest under control so that when and if the disease … arrives, we’re in a better position to control that,” he said.
CDFA Asian citrus psyllid information page: http://www.cdfa.ca.gov/plant/acp/