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America's Least Wanted: Alien Species Invasions of U.S. Ecosystems

​​This seminal report details 12 invasive species that have been especially destructive to U.S. ecosystems, and also summarizes the threats overall posed by invasive alien species while offering solutions to help stem the mounting crisis.

"Of the approximately 4,000 exotic plant species and 2,300 non-native animal species in the United States, most cause few problems," the authors write. "Unfortunately, some alien species are proliferating unfettered, causing severe environmental or economic damage; just 79 of them have cost the U.S. economy $97 billion. Infestations of introduced pest species also are changing the very fabric of our natural ecosystems and pushing endangered species even further toward the brink of extinction." 

Stein BA and Flack SR, eds. 1996. America’s Least Wanted: Alien Species Invasions of U.S. Ecosystems. The Nature Conservancy: Arlington, Virginia.