Efforts to Control Psyllids in California

Grove edges, detector dogs and the California Citrus Research and Field Trials (CA-CRaFT) Program were prominent topics in a virtual presentation about California’s efforts to control HLB-spreading Asian citrus psyllids (ACP). Ivan Milosavljevic, Citrus Research Board (CRB) integrated pest management entomologist, delivered the report. His June 23 presentation was part of the 2026 CRB Webinar Series.

GROVE EDGES

Conventional human scouting at the perimeter, or edges, of groves detected ACP in 27% to 31% of samples, Milosavljevic reported. But in the grove interior, only 1% of samples were found to contain ACP.

Florida researchers have also reported that ACP populations are often higher in grove perimeters; learn more here. 

“Early, low-density infestations are difficult to detect using conventional methods alone,” a slide from the presentation stated.

DOGS ENHANCE EARLY DETECTION

Researchers discovered that ACP detector dogs, used in California groves from 2023 to 2025, enhanced early detection of ACP across coastal and desert regions.

Of 106 blocks surveyed, dogs had 225 ACP alerts. Of those, 199 (88.4%) were confirmed by humans, Milosavljevic reported. There was 100% confirmation by the dogs of known ACP-positive blocks.

Additionally, ACP were found by dogs in seven of 70 blocks that human scouting had previously reported as negative for ACP.

Milosavljevic said ACP confirmation rates for the dogs improved over time, eventually reaching 100%.

The entomologist’s report stated that canine surveys continued to detect infestations missed by conventional scouting under very low ACP pressure, providing evidence that the dogs are an effective early-detection tool.

CA-CRaFT

In 2021, CRB awarded funds to initiate the CA-CRaFT Program to implement ACP mitigation and monitoring, Milosavljevic said in a brief overview of the program.

CA-CRaFT assesses the impact of supplementary mitigation on ACP in Southern California’s citrus groves and confirms best practices for growers. The growers are compensated for treatment expenses and for participating in the program.

Milosavljevic also discussed efforts to use the parasitic wasp Tamarixia radiata to control ACP. Read about that here.