By Alec Rosenberg
Invasive pests not only threaten California's agriculture. They also attack native species that populate our forest ecosystems. California oaks are under siege from sudden oak death in the north and goldspotted oak borer in the south.
UC Riverside entomologist Mark Hoddle is working on aerial surveys of the oak borer here and will travel to Mexico to look for the pest and its natural enemies.
Sudden oak death affects hundreds of plants, with bay laurels the main host responsible for its spread. The disease kills oaks and threatens tanoaks, which are important ecologically for redwoods and wildlife, said Matteo Garbelotto, UC Berkeley associate extension specialist and adjunct professor. Sudden oak death is "a symbol of environmental crisis in the world," Garbelotto said. "We can't really stop it. We have to live with it."
Garbelotto, whose Web site has an interactive map of sudden oak death locations, reconstructed the epidemic, tracking its origins to Santa Cruz and Mount Tamalpais and determining the pathogen can move up to two miles with strong winds. His work helped lead to more thorough inspections and showed that the fungicide Agri-Fos prevents or slows infection.
Garbelotto holds public workshops about sudden oak death. His message: "Pick a small area and commit to it." You can save some trees but not necessarily all. "This is a success story, but there has to be a realization that these programs need to be supported year after year," Garbelotto said.