The San Diego County Department of Agriculture has identified an invasive aloe thrips (Hercinothrips dimidiatus) pest affecting aloe plants across the region. The thrips were first confirmed in San Diego County in 2026, though reports suggest the pest has likely been present longer. The species is also known to occur in Ventura and Santa Barbara counties.
The pest primarily feeds on several aloe species, including Aloe arborescens, Aloe dawei, Aloe munchii, and Aloe vera. Affected plants may show leaf discoloration, including blackening and silvering caused by the insect's feeding, along with dark-colored excrement dots on leaf surfaces. Heavy infestations can lead to plant decline or death.
The adult thrips are approximately 1 millimeter long with three whitish bands, while immature forms are shiny, pale, wingless, and lack banding. The insects require magnification to see clearly. Currently, no scientifically backed control methods are available. Researchers are still working to understand the pest's full lifecycle, host range, and behavior, with upcoming studies intended to provide management guidance.
The County of San Diego Department of Agriculture encouraged residents, growers, and landscapers to report suspected cases to the University of California Cooperative Extension at aloe.thrips@gmail.com or to the California Department of Food and Agriculture's pest hotline at reportapest@cdfa.ca.gov to support statewide tracking and research efforts.