Fusarium dieback-invasive shothole borer is a destructive tree disease caused by invasive beetles that tunnel into trees and introduce harmful fungi

The National Institute of Food and Agriculture awarded $899,826 to University of California, Davis on September 30, 2026, under the Agriculture and Food Research Initiative (CFDA 10.310) to develop early-detection and response tools for Fusarium dieback-invasive shothole borer, a destructive pest-disease complex that has killed or damaged large numbers of trees in Southern California and is spreading northward.

The research team will expand and annually revisit a statewide monitoring network of at least 260 permanent plots containing more than 15,000 trees, including new sites in Santa Clara and Santa Cruz Counties. Researchers will combine field observations, tree inventories, environmental information, and spatial modeling to identify communities especially vulnerable to infestation and to forecast when and where new infestations may occur. The project will develop predictive models comparing practical management options including increased surveillance, sanitation, and targeted tree removal, with the goal of improving allocation of limited surveillance and treatment resources across urban, agricultural, and natural landscapes. The work is particularly critical for California's avocado-growing regions, where potential movement of the pest from urban and natural areas into agricultural production poses substantial economic risk.

Period of performance runs through September 29, 2029, with place of performance at Davis, California.

The pest-disease complex attacks many tree species in cities, parks, riparian areas, wildlands, nurseries, and avocado-growing regions. IT has already killed or damaged large numbers of trees in southern california and is spreading northward. This threat affects more than individual trees: urban and planted forests cool neighborhoods, store carbon, provide wildlife habitat, improve air quality, and protect the quality of life in california communities. Tree removal, replacement, and treatment can also impose substantial costs on homeowners, cities, land managers, and agricultural producers. California supplies most domestically grown avocados in the united states, making the potential movement of the pest from urban and natural areas into agricultural production especially concerning. Managers currently lack reliable tools for determining which locations are most vulnerable, how infestations are likely to move across mixed urban, agricultural, and natural landscapes, and where limited surveillance and treatment resources will have the greatest benefit. This project will combine field observations, tree inventories, environmental information, and modeling to improve early detection and response. Researchers will expand and annually revisit a statewide monitoring network of at least 260 permanent plots containing more than 15,000 trees, including new sites in santa clara and santa cruz counties. Information about tree species, tree health, climate, roads, urban development, waterways, and other landscape features will be used to identify communities that are especially vulnerable and pathways through which the beetles may spread. The team will develop models that forecast when and where new infestations may occur and will compare practical management options such as increased surveillance, sanitation, targeted tree removal, and interruption of important spread corridors. Results will be delivered through an interactive online mapping tool covering 170 california cities. Counties, cities, and other partners will be able to upload their own tree inventories and receive locally relevant risk information, maps, and suggested monitoring priorities. Workshops, webinars, written guidance, and technical assistance will help users apply the information. Ultimately, the project seeks to help communities and agencies detect infestations sooner, respond more quickly, use public resources more efficiently, reduce avoidable tree losses, and better protect california's avocado production, planted forests, urban tree canopy, and natural environments. The approach will also provide a model for responding to other invasive pests that attack many different host species.