Wildlife specialist Terry Messmer, of Utah State University Extension, says that invasive species are plants, animals or pathogens which are non-native (or alien) to the areas where they are now found. These species are the second most significant threat to biodiversity, after habitat loss, according to the World Conservation Union.

In their new ecosystems, invasive species become predators, competitors, parasites, hybridizers and diseases of native and domesticated plants and animals.

The U.S. Department of Agriculture’s National Agricultural Library maintains the National Invasive Species Center, established in 2005 as a repository of information on the new invaders. Although the numbers vary widely, Messmer said research estimates that there are approximately 50,000 in the United States, of which over 4,000 are considered invasive species.

Invasive species cost our country more than $120 billion in damages every year, but there are ways to regulate them.

“The more we know about them – who they are, where they are and how they got there – the greater chance we have of control,” he said. “But the longer we wait to control these species, the greater the damage and the costs of control.”