The upcoming Chinese New Year’s celebration is a bittersweet affair for the California citrus industry.

Giving oranges and tangerines to friends and relatives as a symbol of good wishes is a Chinese tradition for the two week holiday period that begins Feb. 3.

The citrus industry welcomes the increased sales of navels and specialty citrus, but if the fruit originates from back yard trees, the tradition also could spread Asian citrus psyllids, the pest that can carry the bacterial disease, huanglongbing, also known as HLB.

“This pest and the disease are dangerous,” Ted Batkin, president of the Citrus Research Board, Visalia, said in a news release. “If the disease infects a homeowner’s tree, that tree will need to be removed, and the best way to protect our citrus is to control the pest.”

Fruit sold in retail markets will have been properly cleaned and free of the insect, but the industry-sponsored Citrus Pest and Disease Prevention Program is concerned that celebrants may give backyard fruit from southern California. Psyllids, first discovered in California in San Diego County in 2008, have since been trapped in Orange, Los Angeles, Riverside, San Bernardino and Ventura counties.

Quarantines in those regions prohibit moving untreated fruit out of the area, and it is illegal to bring citrus trees and cutting into California, Batkin said.

Batkin and the Citrus Pest and Disease Prevention Program urge New Year’s celebrants to make certain before giving the navels or tangerines that there are no leaves or stems attached to the fruit and that it is thoroughly washed.