Traps have caught five Asian citrus psylla in Santa Ana in Orange County, Calif.
The latest finds will trigger a quarantine, which will restrict host plant movement within 5 miles of the sites, according to a news release. A treatment program is planned.
The California Department of Food and Agriculture also will intensify trapping and surveying to determine how widespread the infestation is.
This marks the first time that the pest has been found outside of a quarantine zone that includes portions of San Diego and Imperial counties.
The finds have raised concern among the citrus industry, especially in light that citrus greening, the citrus disease spread by the psyllid, has been found in Mexico.
"Up until this point, we have been very successful in implementing programs down there [San Diego and Imperial counties] that have kept them contained," says Bob Blakeley, director of grower services for Exeter, Calif.-based California Citrus Mutual.
The good news is so far, no citrus psylla in California or northern Mexico have tested positive for the bacteria that causes citrus greening, also known as Huanglongbing or HLB.
"But we've been of the mind that there's probably backyard landscaping and backyard citrus that are iinfected," Blakely says. "But without the vector, we haven't had the ability to move it. That's why we've focused on keeping the vector out."
On another positive note, Blakely says the public has been cooperative in the two counties where Asian citrus psyllid has been found.
Citrus greening is deadly to citrus trees but harmless to humans.
It causes yield losses and an off-flavor to citrus fruit and eventually kills trees.
Citrus greening is endemic to Florida and has cost the citrus industry there millions of dollars in control and lost trees.
The Asian citrus psyllid was first confirmed in Florida in 1998. Citrus greening was confirmed in 2005.
The disease also has been found in a handful of residential trees in Louisiana, Georgia and South Carolina.
In addition to California and Florida, the Asian citrus psyllid is found in Louisiana, Georgia, South Carolina, Mississippi, Texas and Alabama.
For more information on the Asian citrus psyllid and citrus greening, visit http://www.cdfa.ca.gov/phpps/acp/.