Stopping the Invasion

EAB Invasion

HOW INVASIVE SPECIES TAKE OVER

What happens when a Japanese vine that grows up to a foot a day is introduced to millions of acres of American farmland?

Exactly what you think would happen.

Meet kudzu, a plant first introduced at the 1876 Centennial Exposition in Philadelphia, and then widely planted in the 30s and 40s by farmers to prevent erosion. In the decades since, it’s taken over millions of acres of land and has been found as far north as Canada and as far west as Texas.

Kudzu is just one example of an invasive species, or a non-native plant, insect, animal, or even microbe whose introduction into a new ecosystem causes harm to the environment. There are thousands of them in the United States.

Most non-native plants that qualify as invasive have a few common qualities. They tend to grow quickly, reproduce rapidly, or have aggressive root systems. As they spread, they compete with native species for sunlight and nutrients, and over time tend to crowd out those native species that other organisms depend on.

Invasive plants and insects often arrive in the country as stowaways in shipments. However, a surprising number of these invasive plants were, like kudzu, once brought into the country on purpose.

A perfect case is purple loosestrife. Thanks to its tall, bright purple flowers, it was likely introduced as an ornamental plant in the 1800s. It has since spread across most of the country, where it chokes waterways and offers little food value for native animals.

Invasive insects, meanwhile, can do all that and more. When insects are introduced to ecosystems where they don’t belong, the damage can be almost immediate. Whereas plants spread and crowd, without predators, insects like the emerald ash borer can decimate native populations.

Since the emerald ash borer was first detected in 2002, it has spread across the central and eastern United States, killing tens of millions of ash trees.

Once invasive plants or insects get a foothold in an ecosystem, it becomes extremely difficult (and expensive) to eradicate them. Instead, authorities combat them by learning from past mistakes.

Government agencies, universities, and communities are working together to create mechanisms that prevent the introduction of foreign species, as well as to monitor current infestations and restrict their spread.

With luck, we’ll be able to stop the next kudzu or emerald ash borer before it even begins.