Five Asian citrus psyllids, a pest that could destroy the California citrus industry, have been trapped in Santa Ana, nearly 100 miles north of the U.S.-Mexico border.

It marks the first time psyllids have been trapped north of the border counties of San Diego and Imperial, the California Department of Food and Agriculture said in a news release. The insects were discovered in the traps Aug. 18 and confirmed to be the potentially disastrous bug Aug. 24, the release said.

Psyllids may carry the bacterial disease, huanglongbing – also known as HLB. Testing is under way to determine whether any of the trapped insects was a carrier of the disease.

In June 2008, the insect was discovered for the first time on North America’s west coast when psyllids were found in traps in and around Tijuana, Mexico. More of the pests were later trapped north of the border in San Diego and Imperial counties.

The psyllids found in Santa Ana were in a backyard lemon tree, according to the California Citrus Research Board, Visalia.

The finding of the pests will trigger quarantine. Until it can be established, the Department of Food and Agriculture will restrict movement of potential host plants to and from wholesale and retail nurseries within five miles of the find, the release said. The agency also is planning a treatment program and is trapping and surveying in the area to attempt to detect additional psyllids. 

The revelation of the discoveries in Santa Ana comes just one week after Mexican authorities confirmed the presence of HLB on the Yucatan peninsula, the first confirmed incidence of the disease in Mexico. Earlier this year Mexican authorities indicated the psyllids were present in all of that nation’s 23 citrus growing states.