Asian Psyllid Found in Ventura County Citrus Grove

The California Department of Food and Agriculture, in concert with the Citrus Research Board, Visalia, is increasing trap density following the discovery of an Asian citrus psyllid in Ventura County, one of the state’s major citrus growing counties. This is the first time an Asian citrus psyllid has been found in Ventura County.

The Asian citrus psyllid, which is the size of a fruit fly, feeds on the leaves of lemon and orange trees. It is also known to carry Huanglongbing or HLB, also known as citrus greening disease, that ruins the taste of citrus fruit and juice and then kills the trees. The disease does not affect humans.

The first Asian citrus psyllid found in California was trapped near San Diego more than two years ago, but none of the psyllids found to date has tested positive for the disease. Federal officials are currently testing this psyllid to see if it is carrying HLB, according to Jay Van Rein, spokesman for the state Department of Food and Agriculture.

California citrus industry on alert after the new psyllid find. The lone psyllid was found about Dec. 16 in the La Conchita area at the northern reaches of the county, said Bob Blakely, director of industry relations for California Citrus Mutual, Exeter. The pest was in a trap in a small citrus grove.

“We’re not ready to panic,” Blakely said. “Unless they find another one, we’ll remain cautiously optimistic.”

Asian citrus psyllids have been known to hitchhike on greenery, and the single pest was found at least 20 miles from the closest major commercial groves, he said.

Though just one psyllid was found, its detection triggered a Department of Food and Agriculture quarantine that prohibits the movement of host nursery plants out of the area and requires that citrus fruit be cleaned of leaves and stems before it is packed for shipment. The state agency is working with the grower where the pest was trapped to determine treatment options, according to a news release.

The discovery follows similar insect findings in October in the Montclair and Upland areas east of Los Angeles. Federal, state and local officials have been treating trees in these areas since early this month. Officials have trapped uninfected psyllids in Los Angeles, Orange, Imperial and San Diego counties, and entomologists say they have been expecting the bug to make its way up to the prime citrus-growing regions of Ventura, as well as further north in Kern, Tulare and Fresno counties.

Rain storms that are forecast to continue at least through Dec. 26 are hindering the placing of additional traps, Blakely said.

“But the staff will be getting in and doing visual surveying as soon as the weather permits,” he said.

Monday's announcement comes amid an ongoing effort by an international coalition of citrus farming and agriculture officials to stop the spread of this tiny insect, which in addition to hurting the Florida citrus industry has destroyed miles of farmland overseas.

According to research by UC Davis Cooperative Extension, Florida is losing as much as 12% of its citrus production annually because of the insect and the disease. The insects and the disease have also destroyed an estimated 100 million trees, according to data compiled by the National Academy of Sciences.

State officials and scientists say they fear that it's only a matter of time before citrus greening disease shows up in California.

Citrus is a top ten commodity in Ventura County, home to nearly 22,000 acres of lemon, orange, grapefruit and specialty citrus groves, according to the county agricultural commissioner’s 2009 report. Lemons are the dominant citrus crop covering 17,703 acres.

The County’s citrus industry had revenues of $145 million in 2009, 11% of the state's $1.3 billion citrus industry.