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Department of Agriculture, Weights & Measures

For Immediate Release

Sonoma County coordinating with California Department of Food and Agriculture in response to Asian Citrus Psyllid

SANTA ROSA, CA | February 02, 2023

The Sonoma County Department of Agriculture / Weights & Measures today announced it is coordinating with the California Department of Food and Agriculture in responding to the presence in Sonoma Valley of Asian Citrus Psyllid, a serious pest of citrus that can carry and vector a disease called Citrus Greening disease, or Huanglongbing. 

The county Department of Agriculture sets survey traps each fall and winter in Sonoma County in search of the pest, also known as Diaphorina citri. State officials confirmed its presence following analysis of a survey trap in a residential area east of Sonoma. The pest does not present a threat to Sonoma County’s broader agriculture industry, including wine grape agriculture. 

“Discovery of this pest in Sonoma County is serious and warrants a rapid and coordinated response, including cooperation from nurseries and farmers markets to temporarily regulate the movement of fruit and nursery stock,” said Andrew Smith, Sonoma County Agricultural Commissioner. “While the pest has been encountered in Southern California citrus and there are numerous counties under quarantine, the associated disease has been limited in detection and spread due to early detection programs like in Sonoma County, as well as the concerted and collaborative efforts of property owners and local, state and federal agency partners.”  

The primary impact on Sonoma County is to production nurseries that buy, grow and sell citrus nursery stock, as well as local Certified Farmers Markets and producers that sell or move citrus fruit or plants. There is only one commercial citrus producer in Sonoma County. 

The California Department of Food and Agriculture confirmed the pest in December and immediately began a treatment protocol that included visual survey and treatment of host plants within a 50-meter radius of the original location where the find was collected. Delimitation traps were placed in the four-square miles surrounding the find site at a density of 50 traps per square mile. The delimitation period is 12 months, with traps serviced weekly for the first month, followed by monthly for the remaining 11 months if no more pests are discovered.  

To date, the California Department of Food and Agriculture has discovered and treated citrus host material on eight properties. Treatment is voluntary and includes the use of contact insecticide, as well as a systemic, which are the prescribed treatments by entomologists from the U.S. Department of Agriculture and California Department of Food and Agriculture.

The official notice and proclamation of emergency program from the California Department of Food and Agriculture for the communities surrounding the City of Sonoma, including maps and information, are available at: 

For more information about Sonoma County’s response to Asian Citrus Psyllid, please contact the Department of Agriculture / Weights & Measures by calling (707) 565-2371 or email

Media Contact: 
Dan Virkstis, Communications Specialist
(707) 565-3040