his year marks the 20th anniversary of the UC Statewide T Integrated Pest Management (IPM) Program, which has been dedicated to furthering development and practice of IPM in California by facilitating UC research and extension activities. Its mission remains relevant today in addressing the environmental, social and economic challenges associated with a pest management system in transition. While a sustainable, ecologically based IPM approach has long been a desired goal of IPM developers and practitioners, the current IPM reality varies with the system itself and changes in response to external factors. Variables defining an IPM system include location-specific environmental conditions, the pest complex, resident natural enemies or antagonists, economic and sociological structures, and available research. The availability of IPM-compatible tactics, private and public infrastructure, economic and other incentives, and community support also influence its potential for adoption. IPM as a paradigm is universal; IPM in practice becomes specific to the intended crop, site or situation. The concept of IPM as a continuum has been embraced as a method for defining IPM systems in a manner that maintains the ecologically based goal while acknowledging the limitations of current knowledge. In the IPM continuum, professional scouting and use of available action thresholds are the minimum activities. Monitoring increases knowledge of crop status, pests and beneficial organisms, supporting better-informed pesticide use, and more importantly, decisions not to apply chemicals. Further along the continuum, IPM systems incorporate preventative, nonchemical horticultural or agronomic practices and biologically based tactics such as host-plant resistance, pheromone mating disruption, microbial controls and biological controls. “Reduced-risk” pesticides, which present less risk to human health and the environment, would be used sparingly and only when other options are not possible. At the highest level of the continuum, IPM assures that pest and crop managemeht decisions are integrated and ecologically based. The process of building the IPM continuum identifies the state of the art, as well as gaps in research and available pest control technologies. Conceptualizing IPM as a continuum enables individuals or organizations to evaluate how their current pest management practices relate to what is possible in a nonjudgmental way, while acknowledging the degree to which IPM-compatible practices are being used. California can be proud of the individual growers, organizations and in some cases whole industries that have successfully moved forward along the IPM continuum, yet we have only begun to fulfill IPM’s potential. Researchers in the public and private sectors have developed a remarkable number of practical, IPM-compatible tools. These include new applications of host-plant resistance and biological controls; “reduced-risk” pesticides including microbial agents and mating disruption; new classes of pesticides which are more selective and less disruptive to nontarget species; monitoring approaches like pheromone trapping, degree-day models and immunoassays; precision application techniques for pesticides; and refinements of cultural controls such as canopy management, mulches and sanitation.