Yellow stick traps help monitor for the presence of Asian citrus psyllid in California citrus groves.
Yellow stick traps help monitor for the presence of Asian citrus psyllid in California citrus groves.

Traps continue to pick up Asian citrus psyllids, prompting the state of California to expand an existing quarantine in parts of Tulare County to include the entire county.

The move came after single psyllids were found in residential neighborhoods in the city of Tulare Sept. 10 and 17, according to a news release.

To view all of the psyllid quarantines, visit www.cdfa.ca.gov.

The quarantine prohibits the movement of citrus nursery stock out of the regulated area and requires that all citrus fruit undergo an approved treatment being moved. Fruit also must be free of leaves and stems.

Movement of fruit or plant material from residential dooryards out of the quarantines is prohibited.

In addition to quarantines in portions of Fresno, Kern, and San Luis Obispo counties, psylid quarantines remain in place for all of Imperial, Los Angeles, Orange, Riverside, San Bernardino, San Diego, Santa Barbara, and Ventura counties.

The concern is the Asian citrus psyllid can spread citrus greening, also known as huanglongbing or HLB.

The bacterial disease is harmless to humans or animals, but it can stunt and even kill citrus trees.

In Florida where the citrus disease is endemic, it has caused more than $4 billion in losses to the citrus industry.

Only one tree has been found positive with HLB in California. The residential tree in Hacienda Heights in Los Angeles County was destroyed.