For the last few years citrus growers in the San Joaquin Valley have been nervously watching the establishment of Asian citrus psyllid in southern California and bracing themselves for the day of northward movement. That day arrived in November 2012 when two psyllids (Strathmore 16 Nov. and Terra Bella 21 Nov.) were caught on yellow sticky card traps, in addition to a third capture back in January 2012. These captures have now resulted in restrictions on the movement of citrus in the heart of California's principal citrus production region.

Asian citrus psyllid is a small insect the size of an aphid that feeds on citrus leaves and stems. It is the vector of a deadly bacterial disease of citrus called huanglongbing, often referred to as HLB or citrus greening. This pest and disease combo has resulted in devastating losses to the citrus industry in Florida, and has the potential to have a similar effect in California.

Prior to November 2012 Asian citrus psyllid had been reported in eight California Counties, mostly in the southern part of the state, with a combined total of approximately 26,000 square miles under quarantine.

However, the two finds in Tulare County mark the first time the psyllid has been found in the heart of California's principal citrus production region of the lower San Joaquin Valley: citrus production in Kern, Tulare and Fresno counties totals more than 200,000 acres at an annual value of approximately $1.7 billion.

The capture of individual psyllids on sticky traps in Strathmore and Terra Bella gives CDFA the authority to establish a quarantine of citrus within a 20-mile radius of the find in Strathmore. As an interim step, CDFA has opted to only regulate citrus in a 5-mile radius around each find. Further trapping and delineation can determine if psyllids are truly established in the region, or if the psyllids caught were just non-breeding hitchhikers brought to the corridor along State Highway 65 from infested counties in Southern California. Within the five-mile regulated area is an eight-hundred meter eradication zone requiring mandatory treatment of all host plants. If further delineation detects an established population it is anticipated that quarantines would be established. If established, a quarantine for Asian citrus psyllid would last a period of two years from the most recent capture. If additional psyllids were captured during the two-year quarantine the clock would reset itself for another two years.