Risk, spread, and control of Fusarium dieback – shot hole borers throughout native plant communities in San Diego County

Type: report

Article abstract: The devastating effects of FD-KSHB on native riparian habitat in the Tijuana River Valley is of great concern to land managers in San Diego County, especially as many new infested sites continue to be identified throughout the region. These plant communities serve as critical breeding habitat for species such as the endangered least bell’s vireo (Vireo bellii pusillus; LBVI) (Kus 2002) and southwestern willow flycatcher (Epidomax traillii extimus; SWFL) (Craig and Williams 1998). Our work points to a path forward to make informed decisions on best approaches to management in the short- and long- term. In this project, our objectives were to 1) determine KSHB distribution with respect to key least Bell’s vireo and southwestern willow flycatcher habitat; 2) develop a predictive model for which specific native habitats are most vulnerable to FD-SHB invasion and impacts, based on an understanding of the evolutionary ecology of the fungus and beetles, beneficial endophyte distribution, a landscape analysis of vegetation and surrounding avocado groves, and environmental conditions; 3) evaluate biological control potential of beneficial endophytic fungi and bacteria; 4) assess the efficacy of application methods of entomopathogens suppressive to ISHB; 5) evaluate water-based latex paint as a means to track ambrosia beetle activity on infested trees; 6) evaluate efficacy of pesticides in suppressing beetle populations on critical host species; and 7) evaluate pesticide residues on critical host tissues.

Number of pages: 61

Authors: Eskalen, Akif; Gilbert, Gregory; Lynch, Shannon; Stouthamer, Richard;

Year: 2022

Prepared for: San Diego Association of Governments;

Keywords: Kuroshio Shot Hole Borer; polyphagous shot hole borer; Shot hole borer;

Vegetation communities: riparian forest & scrub

Threats: Invasive animals