Biological control for sustained ACP suppression

Ventura County supports ACP activity for much of the year due to mild climate, frequent flush, and a highly mixed landscape that includes commercial groves, organic production, and unmanaged citrus. Under these conditions, ACP populations persist and rebound quickly, requiring long-term suppression.

CA-CRaFT in Ventura focuses on building a biological control system based on Tamarixia radiata, a natural enemy of ACP. This program is designed to expand across approximately 2,000 acres of commercial citrus, creating a coordinated network of participating groves.

Participating blocks will host field-based Tamarixia release systems that continuously produce and release parasitoids directly into citrus. Ongoing release allows beneficial populations to build within orchards and move into surrounding areas, creating sustained pressure on ACP.

Program staff install and maintain these systems, which consist of curry leaf plants that support ACP reproduction without risk of HLB, allowing continuous Tamarixia production. Fine mesh cage structures retain ACP within the system while allowing Tamarixia to disperse into adjacent trees. Monthly visits ensure consistent production, system maintenance, and monitoring of ACP and parasitism levels. Results are shared with growers throughout the season so progress remains clear and measurable.

This approach supports long-term suppression rather than repeated short-term control. The fit is strong for organic systems, reduced-input programs, and areas where spray options are limited. Ant management is encouraged where needed, as Argentine ants reduce Tamarixia effectiveness. Annual drone imagery will also be used to evaluate canopy condition and support reporting across participating acreage.