In San Mateo County there were two confirmed finds in the fall of 2015 of the insect Diaphorina citri, also know as Asian Citrus Psyllid (ACP).  Asian Citrus Psyllid was first discovered in California in 2008 and has spread throughout the southern part of the state.  The interception has prompted a partial quarantine in the county as well into San Francisco County.  Insect traps have been deployed throughout the county to detect further populations and establish the distribution of the pest.  

Asian Citrus Psyllid is a small insect, about the size of an aphid that may vector the fatal Huanglongbing (HLB) bacterium, sometimes refered to as Citrus Greening disease.  ACP is the only known insect that can carry the disease which starts as overall decline in health of the tree, with bitter and misshapened fruit, and always results in death of the tree.  There is no known cure once infected with HLB.  As noted in it's common name, citrus and closely related species may host the insect and disease.  

With California's $2 billion citrus industry at risk, it is important that we work together as a community to stop the insect from spreading.  Watch this video to see how you can help.  If you suspect the insect or disease is on your citrus trees, please call your local agricultural commissioner's office at (650) 363-4700 or CDFA's pest hotline at (800) 491-1899.    

More identification, management and educational information may be found at: UC Davis IPM for Asian Citrus Psyllid and UC Division of Agriculture and Natural Resources

Quarantine information including maps are available at the California Department of Food and Agriculture.