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Invasive animals threaten native species, damage agricultural crops, and pose health risks to humans.
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Some of the strangest invasive species include hammerhead worms and giant snails.
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Here are six unique species causing problems in the US.
An invasive species is any species (plant, animal, or insect) that is present in an ecosystem to which it is not native and that causes, or is likely to cause, economic or environmental health or poses a risk to humans, according to the Department of agriculture of the United States.
Invasive species in the United States can pose a threat to native plant and animal species (including endangered species), disrupt agriculture, damage infrastructure, and pose risks to human health. Invasive species are most commonly spread by humans: for example, one can travel in shipments around the world.
Eradicating invasive species, like successful efforts involving alligators in Florida, can take decades and millions of dollars.
Here are six unique invasive animal species causing environmental destruction in the US.
Otter
Otters are large aquatic rodents that resemble a cross between a beaver and a large rat. Like beavers, they have bright orange teeth due to a special iron-containing enamel. These stocky rodents, which notably lack a neck, can grow to be two feet long and weigh 20 pounds.
Otters are native to South America, but were brought to the US in the late 1890s as part of the fur trade. According to the USDA, many escaped or were freed in the 1940s after the collapse of the fur trade. The invasive species has now spread to at least 20 states, primarily in Gulf Coast states like Louisiana and Florida.
Otters cause environmental destruction in part due to their ferocious eating habits. They consume up to 25% of their weight in plants daily with a feeding strategy that involves digging, which can destroy soil, disturb native plants, cause erosion and damage infrastructure.
Giant African land snail
The giant African land snail can grow up to 8 inches long. The species is native to East Africa and is considered one of the most destructive snails in the world.
The invasive species was introduced to Hawaii in 1936 and to the continental United States in 1966, according to the USDA. When snails were found in Florida in the 1960s, the eradication effort cost $1 million and took ten years. However, snails have been discovered again in Florida recently, for the third time in the state’s history.
Snails eat at least 500 different plants and can cause damage to plaster and stucco infrastructure. The snails, which can reproduce 1,200 eggs a year, also carry a parasite that can cause meningitis in humans.
Shovel-headed garden worm
Spadehead garden worms, native to Southeast Asia, can grow up to a foot long and have flat bodies with long stripes. They are also known as hammerhead worms, thanks to their flat, spade-shaped head that resembles that of a hammerhead shark.
Worms first arrived in the US in 1891 and can be found in states such as Texas, Arkansas, and Georgia. Earthworms are effective predators and feed on earthworms, which are essential for maintaining soil health.
“If earthworms were eliminated, then our plants won’t get the nutrients they need,” Ashley Morgan-Olvera, a researcher at the Texas Invasive Species Institute, told Texas Monthly. “This could affect the way our yards, our gardens and our farm fields grow.”
Asian longhorned tick
Asian longhorned ticks are about the size of a sesame seed and are native to eastern China, Japan, eastern Russia and Korea. The light brown ticks have been in the U.S. since at least 2010 and have spread to several eastern states, according to the USDA.
The invasive species poses a threat to wildlife and has been found to infest animals such as sheep, goats, dogs, cats, horses, deer and people. They have even killed cattle. In 2021, an Ohio farmer found three of his cows dead and covered in Asian longhorned ticks.
Ticks can also clone themselves (or reproduce without a male), so a single tick is capable of starting a new population by laying 2,000 eggs.
Emerald ash borer
The emerald ash borer is a small beetle native to eastern Asia that was first detected in the U.S. in 2002. About the size of a grain of rice, the beetle is a stunning, bright jewel-green shade. Emerald ash borer infestations have been discovered in 36 states.
As a wood-boring pest, the invasive species lays its eggs in the bark of an ash tree. The larvae then make their way into the tree and feed on its tissues. Boring disrupts the tree’s food and water intake and eventually kills it.
Since arriving in the U.S., emerald ash borers have decimated American ash trees, killing tens of millions nationwide. Scientists say it is the most destructive pest to ever hit America’s forests.
Wild pigs and super pigs
Pigs, native to Europe and Asia, were brought to the U.S. in the 16th century by early explorers as a food source. Feral pigs in the U.S. today are the same species as pigs found on farms, according to the USDA, and are descendants of pigs that escaped or were released. Today, feral hogs can be found throughout the South and in California.
However, Canadian-bred “super pigs” may also be invading the US from the north. Superpigs, a cross between a domestic pig and a European wild boar, were bred decades ago to produce larger pigs. Super pigs grow thick, shaggy coats, equipping them to survive winters in Canada and the northern United States.
The pigs, which can weigh more than 600 pounds, feed on native species such as frogs, salamanders and ground-nesting birds such as ducks and geese. They also destroy agricultural crops by tearing up the soil while scavenging for plant roots and insect larvae.
There have been some documented cases of superpigs in North and South Dakota, but the animals have not been able to establish a permanent population, for now.
Read the original article on Business Insider
