Polyphagous Shot Hole Borer (PSHB) at UC Irvine
Tuesday, November 1, 2016– The Polyphagous Shot Hole Borer (PSHB) and plant disease known as Fusarium dieback persist within UCI’s urban forest and natural areas and continue to spread across the region. A recent survey at UCI identified 1,500 trees with PSHB and Fusarium dieback within the campus core and student housing areas. Approximately 1,000 trees have also been identified with the beetle-disease complex in University Hills. Shot Hole Borers (including the closely related Kuroshio Shot Hole Borer) have now spread throughout Orange, San Diego, Los Angeles, Riverside, San Bernardino, and Ventura counties and their occurrence has been recently confirmed in Santa Barbara County. The beetle-disease complex has caused severe damage to a wide variety of trees within both urban forests and natural areas.
UCI continues to manage the PSHB beetle-fungus complex on campus through implementation of Best Management Practices (BMPs) developed collaboratively among UCI, the University of California’s Division of Agriculture and Natural Resources (ANR), and UC Riverside scientists. As findings from research on our campus and regionally have become available, UCI is updating its BMPs for surveying, assessment, treatment, and removal of infected trees.
Approximately 500 trees on campus that were severely damaged by PSHB were removed last year, and 150 additional trees have been identified for removal based on recent campuswide surveys and assessment. Tree removals will move forward this month, and campus staff will continue to work with stakeholders in impacted campus areas where a significant number of trees or extremely large trees require removal.
The campus is continuing its reforestation efforts with the goal of replacing the tree canopy lost to the beetle-fungus complex with a diverse range of species selected based on potential resistance to PSHB. The first phase of reforestation occurred last spring and replaced the tree canopy lost in the most heavily impacted areas of campus. The second phase of reforestation will be implemented this winter and will replace approximately 150 trees lost in the central academic core.
Information regarding the status of the regional PSHB infestation, including the current geographic range of the infestation and steps to take when reporting PSHB infected trees, is available at http://ucanr.edu/sites/socaloakpests/Polyphagous_Shot_Hole_Borer/ and http://eskalenlab.ucr.edu/links.html.
University Hills residents who have questions regarding trees in common areas or private property in University Hills should contact Andrew Herndon at Andrew.Herndon@icha.uci.edu.
Regional beetle infestation prompts removal of UCI trees – UCI News April 17, 2015
Scientists fight to save iconic UC Irvine trees from invasive beetle – 89.3 KPCC July 21, 2015