Psyllid Study to Determine Degree of HLB Risk

Len WilcoxCalifornia Corner, Psyllids

Asian citrus psyllid

University of California Riverside Extension Specialist Monique Rivera said that funding for a new research project to study the Asian citrus psyllid (ACP) has been approved. The project will take a closer look at the phenology of huanglongbing (the citrus disease ACP spreads) and its prevalence in psyllid populations. The scientists will be looking for patterns that will help them predict whether a citrus grove is at risk for huanglongbing (HLB).

“Another way of putting that would be, ‘How frequently do you find psyllids that have the bacterium throughout the year, and is there any sort of pattern to that?’ So that’s the question we would be answering with this,” Rivera explained. “This would be something that we would do to update risk models in California.” She added that the study aims to answer the question of what the risk is to growers if they have ACP in their groves.

According to Rivera, the project specifically involves sampling psyllids for HLB. That’s important because it is not known what percentage of psyllids in California are carrying the pathogen in groves. “And that’s a crucial number to figure out in order to determine risk,” Rivera said. “If they (growers) have ACP in their grove, we don’t know the direct correlation between how many points of infection are really needed to get that full blown pathogenesis yet.”

The presence of ACP in a grove indicates there is a risk. The research should help scientists understand the degree of risk relative to the concentration of ACP in the grove. The project will begin in early 2021.

About the Author

Len Wilcox

Correspondent at Large for Citrus Industry Magazine and AgNet West