This 7.2-mile stretch of riparian habitat is the project area of the San Luis Rey River Flood Risk Management Project. For years, this portion of the San Luis Rey River was overgrown with many invasive non-native plants like giant weed (Arundo donax), salt cedar (Tamarix sp.), and castor bean (Ricinus communis). The high abundance of these exotics diminished the quality of the habitat for the federally listed species and added to the dense vegetation that could lead to the increase of flood risk.
In 2003, a single PSHB beetle was caught in a CDFA trap in Long Beach. The beetle went unnoticed until 2012 when it was found damaging backyard avocado and urban forest trees in the Los Angeles basin. A rapid monitoring response uncovered the broad host range of the pest-disease complex, but its ability to establish in native vegetation was only gradually recognized.
SERCAL 2016 Technical Session — Mono Lake / Desert Systems