Thanks to a grant from CAL-FIRE, the Ventura County Agricultural Commissioner’s Office is initiating work to remove diseased and dying trees that have been infested by the Invasive Shot-Hole Borer (Euwallacea sp.), a small invasive beetle that rapidly destroys its host trees by infecting them with a destructive fungus (Fusarium euwallacea).
The project’s initial tree removal took place on Friday, March 20, 2020, at a private residence in Meiners Oaks. The large boxelder (Acer negundo) tree was infested with the beetle and was diseased and dying. The tree was also threatening the homeowner’s residence and posed the threat of spreading the beetle to the surrounding area. The Boxelder tree is the Invasive Shot-Hole Borer’s top host, making this tree species of special concern for removal.
“It is important homeowners and residents are aware of the health of the trees and vegetation that surround their homes or properties,” said Ed Williams, Agricultural Commissioner. “We recommend that all woody brush cleared in our area be chipped to less than one inch and composted or solarized under plastic for a few weeks to kill all of the beetles and fusarium disease. It is also important for campers in Ventura County to buy their firewood where they burn it to avoid moving pests from one area to another.”
The tree removal project could pay for removal of a few hundred diseased or dying trees, with the goal of stopping or limiting the spread of the Invasive Shot-Hold Borer beetle, and the fungus. Removal of these diseased and dying trees will help protect Ventura County and stop/limit the spread to non-infested areas. Dead and dying trees created by the infestation are potential dangers due to dropping limbs and building ready fuel for fires in both residential and urban areas.
The Invasive Shot Hole Borer has been rated “B” by the California Department of Food and Agriculture. The designation is given to an aggressive invasive species that is absent or limited in parts of California. The Invasive Shot-Hole Borer and Fusarium fungus can infest and kill up to 65 different types of native, agricultural, and urban trees. Ventura County is on the leading edge of the infestation, and at the forefront of the state’s efforts to stop it from spreading.