PersPective A River System to Watch: Documenting the Effects of Saltcedar (Tamarix spp.) Biocontrol in the Virgin River

Throughout riparian areas of the southwestern United States, non-native saltcedar (also known as tamarisk; tamarix spp.) can form dense, mono-typic stands and is often reported to have detrimental effects on native plants and habitat quality (Everitt 1980; Shafroth et al. 2005). Natural resource managers of these riparian areas spend considerable time and resources con-trolling saltcedar using a variety of techniques, including chemical (Duncan and McDaniel 1998), mechanical, and burning methods (Shafroth et al. 2005). Approximately one billion dollars are spent each year on river restoration projects nationally (Bernhardt et al. 2005), and a majority of these projects focus on invasive species control in the Southwest (Follstad Shah et al. 2007). A technique that has drawn much attention is the use of the saltcedar leaf beetle (Diorhabda spp.), a specialist herbivore, as biological control of saltcedar (Lewis et al