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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 stranger invasive species include hammerhead worms and giant snails.
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Here are six unique species that are 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 ecological health or poses a risk to humans, according to the Department of Agriculture of the United States.
Invasive species in the US can threaten native plant and animal species – including endangered species – disrupting agriculture, damaging infrastructure and posing health risks to people. Invasive species are usually spread by humans: for example, you can hitch a ride on shipments around the world.
Eradicating invasive species, like the successful efforts with caimans in Florida, can take decades and millions of dollars.
Here are six unique invasive species causing environmental destruction in the US.
Nutria
Nutria are large, aquatic rodents that look like a cross between a beaver and an oversized rat. Like beavers, they have bright orange teeth thanks to a special enamel that contains iron. The round rodents, which mainly have no neck, can grow to sixty centimeters in length and weigh twenty kilos.
Nutria is native to South America, but was brought to the US in the late 1890s as part of the fur trade. According to the USDA, many escaped or were released in the 1940s after the fur trade collapsed. The invasive species has now spread to at least 20 states, mostly in Gulf Coast states such as Louisiana and Florida.
Nutria cause environmental destruction in part because of 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, disrupt native plants, cause erosion and damage infrastructure.
Giant African land snail
The giant African land snail can grow up to 20 centimeters in length. The species is native to East Africa and is considered one of the most destructive snails in the world.
According to the USDA, the invasive species was introduced to Hawaii in 1936 and to the mainland US in 1966. When the snails were found in Florida in the 1960s, the eradication cost a million dollars and took ten years. However, the snails were recently rediscovered in Florida for the third time in the state’s history.
The snails eat at least 500 different plants and can cause damage to plaster and plaster infrastructure. The snails, which can produce 1,200 eggs a year, also carry a parasite that can cause meningitis in humans.
Garden worm with shovel head
Spade-headed garden worms, native to Southeast Asia, can grow to a foot long and have flat bodies with long stripes. They are also known as hammerhead sharks, thanks to their flat, shovel-like head that resembles that of a hammerhead shark.
The worms first arrived in the US in 1891 and can be found in states such as Texas, Arkansas and Georgia. The worms are effective predators, feeding on earthworms, which are essential for maintaining soil health.
“If earthworms were eliminated, our plants wouldn’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 fields grow.”
Asian longhorn tick
Asian long-horned ticks are about the size of a sesame seed and are native to eastern China, Japan, eastern Russia and Korea. The tan ticks have been present 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 in animals such as sheep, goats, dogs, cats, horses, deer and humans. They even killed livestock. In 2021, a farmer in Ohio found three of his cows dead and covered in Asian longhorn ticks.
The ticks can also clone themselves – or reproduce without a male – so that a single tick can start a new population by laying 2,000 eggs.
Emerald ash borer
The emerald ash borer is a small beetle native to East Asia and first discovered in the US in 2002. The beetle is about the size of a grain of rice and is a stunning, glossy shade of jewel green. Emerald ash borer infestations have been discovered in 36 states.
As a wood-eating pest, the invasive species lays its eggs on the bark of an ash tree. The larvae then eat their way into the tree and feed on the tissues. The drilling disrupts the tree’s food and water intake, eventually killing it.
Since arriving in the U.S., emerald ash borers have decimated American ash trees, killing tens of millions of people across the country. Scientists say it is the most destructive pest to ever ravage American forests.
Wild pigs and super pigs
Pigs, native to Europe and Asia, were brought to the US by early explorers in the 16th century as a food source. According to the USDA, feral pigs in the U.S. today are the same species as pigs found on farms, and are the descendants of pigs that have escaped or been released. Today, feral pigs can be found throughout the South and California.
However, it is possible that Canadian-bred “super pigs” could also invade the US from the north. The super pigs, a cross between a domestic pig and a European wild boar, were bred decades ago to make larger pigs. The super pigs grow thick, hairy coats, allowing them to survive winters in Canada and the northern US.
The pigs, which weigh more than 600 pounds, prey 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 land as they search for things like plant roots and insect larvae.
There have been some documented occurrences of the super pigs in North and South Dakota, but the animals have so far failed to establish a permanent population.
Read the original article on Business Insider