Asian citrus psyllid was first found in the United States in Palm Beach County, Florida, in June 1998. By 2001, it had spread to 31 counties in Florida. In 2001, ACP was accidentally introduced into the Rio Grande Valley in Texas. It was subsequently found in Hawaii in 2006, and in Alabama, Georgia, Louisiana, Mississippi, South Carolina and California in 2008.

Five Asian citrus psyllids have been recently detected in traps in Santa Ana, California, the first time the pest has been trapped north of San Diego and Imperial counties.

Until a likely quarantine can be established, the California Department of Food and Agriculture will restrict movement of regulated plant material, including host plants, at wholesale and retail nurseries within five miles of the find site. Additionally, CDFA is planning a treatment program and is trapping and surveying in the area in an attempt to detect additional psyllids.

"The Asian citrus psyllid is a dangerous pest of citrus," said CDFA secretary A.G. Kawamura. "We must move quickly to identify the full extent of the problem and do all we can to protect our state's citrus industry."

The major concern is that the pest can carry the disease huanglongbing (HLB). All citrus and closely related species are susceptible hosts for both the insect and the disease. There is no cure once a tree becomes infected. The diseased tree will decline in health until it dies. HLB has not been detected on trees in California.

The state of Florida first detected the pest in 1998 and the disease in 2005, and the two have now been detected in all 30 citrus producing counties in that state. The pest and the disease are also present in Louisiana, Georgia and South Carolina. The states of Texas, Mississippi and Alabama have detected the pest but not the disease.