Biological control of saltcedar (Tamarix spp.) was initiated in 1987, using host-specific insect herbivores that are thought to regulate this plant in the Old World. After quarantine evaluation and regulatory approval, the leaf beetle Diorhabda elongata was released into field cages at 10 approved sites in 6 states in 1999 and into the open environment in May 2001. These beetles have now been tested at several locations where they have successfully overwintered, established reproductive populations and spread substantially within saltcedar infested areas. Within these sites, the beetles have caused extensive defoliation for multiple seasons and are severely impacting saltcedar growth and development. The impact on the saltcedar has been extensive while no non-target plants have been impacted. In some areas the beetles have defoliated over 5000 acres of saltcedar. However, these beetles failed to establish in Texas and California. Thus additional strains of Diorhabda beetles were collected and tested in 2002 and released into the field in Texas, New Mexico, and California during late 2003 and 2004. They overwintered well and are increasing in numbers where we expect that they too will cause extensive defoliation. Thus, biological control seems to be providing self-sustaining, permanent, safe, and low cost control of saltcedars in many areas and is being considered by USDA-APHIS and others, for wide-area use in 2005. This project is expected to allow recovery of native riparian plant communities, improved wildlife and fish habitat, reduced wildfires, and increased availability of water in many areas across the western US.