First Detection of Asian Citrus Psyllid in Citrus Orchard Reported

Taylor HillmanCitrus

Adult Asian citrus psyllid, Diaphorina citri Kuwayama. Photograph by Douglas L. Caldwell, University of Florida.

Adult Asian citrus psyllid, Diaphorina citri Kuwayama. Photograph by Douglas L. Caldwell, University of Florida.

The detection of a single adult Asian citrus psyllid (ACP) found in a commercial citrus orchard in the southern most portion of San Luis Obispo County has prompted a high-density trapping delimitation survey of the surrounding area.

A new quarantine restricting the movement of citrus nursery stock and citrus fruit will be established by the California Department of Food and Agriculture (CDFA) to prevent the spread of this serious plant pest to other citrus-growing sites. Control efforts will take place in the near future in the orchard.

This is the third detection of ACP in southern San Luis Obispo County. Intensive trapping and visual surveys are ongoing, but no additional insects have been detected at the new site or at the two previous Arroyo Grande detection sites. The psyllid has also been found in the City of San Luis Obispo and Cayucos in 2014. To date, no other psyllids have been detected at these sites.

“The detection of the Asian citrus psyllid in a commercial orchard is serious because of the threat of huanglongbing, a plant disease that is fatal to all types of citrus trees. Huanglongbing can be carried from tree to tree by this pest,” according to Martin Settevendemie, agricultural commissioner/sealer for San Luis Obispo County. Commercial citrus orchards located throughout the county produced fruit valued at over $17 million in 2014. The disease does not affect human health and citrus fruit is safe to consume. A single citrus tree infected with huanglongbing was found in a Los Angeles County backyard in 2012. To date, no additional detections of the disease in California have occurred.

Staff from the San Luis Obispo County Agricultural Commissioner’s office and officials from CDFA continue to search for this pest by monitoring hundreds of insect traps placed in urban neighborhoods and commercial orchards throughout the county.

Commercial citrus growers are urged to contact the San Luis Obispo County Department of Agriculture at 805-781-5910 to ensure that all quarantine requirements are met to help prevent the spread of Asian citrus psyllids.

The public is encouraged to purchase citrus trees from reputable local sources that have been routinely inspected by the agricultural commissioner’s staff and purchase citrus fruit from local farmers’ markets or supermarkets.

For more information about the Asian citrus psyllid, visit the CDFA website at