Start Date: Jul 12, 2005
End Date: Feb 16, 2010
Exotic invasive weeds cause about $27 billion annually in economic losses in addition to environmental impacts ranging from displacement of species of conservation concern to altered ecosystem functions. Biologically-based control methods can provide cost-effective, sustainable means of limiting the adverse impacts of invasive plants over extensive rangeland and natural areas. Our studies will focus on increasing the success of biological control efforts through better scientific understanding of: mechanisms underlying both the impact of agents and patterns of weed and agent dispersal; genetic variation within target weeds and biological control agents; evolutionary relationships of target weeds and agents; synergisms between plant pathogens, deleterious microbes, and arthropod agents; direct and indirect effects of biological control introductions on nontarget organisms in a risk analysis context; environmental factors affecting weed and biological control agent dynamics and invasion risk; and follow-on effects following suppression of weeds by biological control agents. Anticipated products of our project include new biological control agents, improved systematic and phylogeographic understanding of target weeds and control agents, improved systems for assessing and monitoring weed and insect populations; elucidation of factors and mechanisms limiting the establishment and success of biological control releases. This will benefit land managers, users of public lands, the general public, and the scientific community in the fields of invasive plant ecology, systematics and biological control.