The Los Angeles Times reported this afternoon that Asian citrus psyllid has been found in a Los Angeles County backyard citrus tree. Just yesterday, officials confirmed the pest was found in Orange County. These were the first finds outside of San Diego and Imperial counties, where the exotic pest was first captured in California in early 2008.

UC citrus entomologist Beth Grafton-Cardwell is asking Californians to pitch in on the battle against Asian citrus psyllid, which in other parts of the world carries the devastating citrus disease Huanglongbing (HLB, or citrus greening disease.)

Anyone with a citrus tree in their yard or apartment complex can look closely at the tender young leaves of the late summer and fall citrus flush, the place where immature stages of Asian citrus psyllid congregate. The small, yellowish-orange nymphs extract sap from the tree as they feed. They excrete honeydew, which can turn leaves and fruit black from sooty mold, and they produce tiny white, waxy tubules.

For more information, see http://ucanr.org/detectingpsyllids. For pictures of Asian citrus psyllid and the symptoms to look for in infested trees, see the accompanying video.