The Department of Agriculture/Weights and Measures Reports the Detection of an Asian Citrus Psyllid
Author: David Aguayo, Asst. Agricultural Commissioner / Sealer
Date: 9/29/2026 1:35 PM
An adult Asian citrus psyllid (ACP) was recently detected in Los Osos, prompting increased trapping, visual surveys, and response activities by state and local agricultural officials. Learn more about the detection, why ACP poses a threat to citrus, and what residents in the area can expect in the coming weeks.
One adult Asian citrus psyllid (ACP) was recently detected in an insect trap at a Los Osos residence, prompting increased trapping, visual surveys, and response activities in the surrounding area.
The California Department of Food and Agriculture (CDFA), in collaboration with the San Luis Obispo County Department of Agriculture/Weights and Measures, is leading the response. CDFA and County Agricultural Commissioner staff will conduct high-density trapping, visual surveys, and treatments around the detection site to determine whether additional ACP are present and reduce the risk of the pest spreading.
“This detection demonstrates why we maintain an extensive pest detection network throughout San Luis Obispo County,” said Martin Settevendemie, San Luis Obispo County Agricultural Commissioner/Sealer. “Finding invasive pests early gives us the best opportunity to respond effectively. We appreciate the cooperation of Los Osos residents as CDFA and Department staff conduct surveys, trapping, and treatments in the area.”
Residents in and around the affected area may see CDFA and County Agricultural Commissioner staff conducting trapping, visual surveys, treatments, and other response activities over the coming weeks. Resident cooperation is an important part of protecting citrus in San Luis Obispo County.
CDFA is also planning an online public information meeting to provide information about the detection and response and give residents an opportunity to ask questions. The meeting date and details will be announced in the coming weeks through additional outreach and news releases.
Asian citrus psyllid is a serious threat to California citrus because it can spread Huanglongbing (HLB), also known as citrus greening disease. While ACP and HLB are harmless to humans and pets, HLB is an incurable plant disease that is fatal to citrus trees.
Preventing the spread of ACP and HLB is important to protecting both commercial citrus production and citrus trees in residential landscapes.
The Department of Agriculture/Weights and Measures, in cooperation with CDFA, routinely monitors for ACP and other invasive agricultural pests using insect traps placed in residential neighborhoods and commercial agricultural areas throughout the county.
Early detection, rapid response, and community cooperation are important tools for protecting San Luis Obispo County agriculture and residential citrus.
