RISK, SPREAD, AND CONTROL OF FUSARIUM DIEBACK - SHOT HOLE BORERS IN SOUTHERN CALIFORNIA.
Shannon C. Lynch; University of California Santa Cruz; 1152 High Street, Santa Cruz, CA, 95060; (951) 534-2819; sclynch@ucsc.edu; Akif Eskalen, Gregory S. Gilbert
The exotic pest-disease complex Fusarium dieback (FD) is a serious threat to the viability of native riparian and oak woodland plant communities in Southern California. FD is formed by two invasive shot hole borer (SHB) beetle species (Euwallacea sp.), each associated with specific fungal pathogen species (Fusarium sp.). The broad host range has fostered rapid spread throughout urban-wildland forests and commercial avocado groves throughout the region. Our research goal is to support the development of a policy and management response in-line with the magnitude of the problem. Our objectives are to 1) Develop a predictive model for which specific sites are most vulnerable to FD invasion and impacts based on an understanding of the evolutionary ecology of the fungi and beetles, beneficial endophyte distribution, environmental conditions, and landscape factors; 2) Identify endophytic candidates for consideration as a management response. We established 260 permanent study plots containing at least 50 geo-referenced trees in FD-infested and non-infested oak woodlands, riparian corridors, and avocado groves throughout Southern California. Antagonism assays indicate that local endophytic bacteria collected from xylem of selected trees in a subset of plots formed zones of inhibition against the fusaria pathogens, showing promise of environmentally safe biocontrol treatments.
The Anthropocene: Pathogens & Invasive Species   Student Paper