Given that California maintains a wide variety of ecological niches, invasive pests, both plants and invertebrates, can become quickly established. That’s one of the many reasons why in October 2009, the U.S. Department of Agriculture's Animal Plant Health Inspection Service developed a study (USDA Farm Bill States Risk Report) ranking California #1 among states with a high risk of introduction of exotic pests.

According to an update on the environmental and economic costs associated with alien-invasive species in the United States released by Cornell University approximately 50,000 species of plants and animals have invaded the United States and caused a wide array of damages to managed and natural ecosystems. An estimated 5000 plant species have escaped and now exist in U.S. natural ecosystems (Morse et al., 1995), compared with a total of about 17,000 species of native U.S. plants (Morin, 1995).  Most of the 5000 alien plants established in U.S. natural ecosystems have displaced several native plant species (Morse et al., 1995). Alien weeds are spreading and invading approximately 700,000 ha/year of the U.S. wildlife habitat (Babbitt, 1998).  In California alone, more than 3000 plant species have been introduced (Dowell and Krass, 1992).

Moreover, data collected from the U.S. Forest Service regions indicate that approximately six to eight million acres of National Forest lands are infested with invasive plants across the nation. In California, eighteen national forests cover 20 percent of the land, or 20 million acres, across 39 of our 58 counties.

Invasive species and noxious weed management is a problem of epic proportion in California. According to the California Invasive Plant Council, each year, $82,000,000 is spent to control noxious weeds that infest millions of acres in California. Left unmanaged weeds on USFS lands create a reserve of noxious weeds that proliferate to private land thus increasing the costs to state and local weed management programs. Owners of livestock are impacted as they cannot graze ruminant animals, and frequent users of public land are disappointed with declining forest productivity and loss of wildlife habitat.

• Blue Ribbon Panel Report for Pest Exclusion in California 94.0103
• Definitions of Integrated Pest Management 1990-1998
• Govt Agencys Definitions of Integrated Pest Management 04.1201
• Guide_to_Pesticide_Use_in_CA
• High Risk Pest Program 05.0228
• NSA NAPPO Pest Risk Anaylsis 08.0515
• Pesticide Use Enforcement_Program_Standards_Vol_3
• Residual Mill Assessment Fund MOU