From lovebugs to nutrias: Korea grapples with growing threat of alien species

Love bugs or Plecia nearctica swarms Korea up to the end of June Yonhap photo — This photo shows love bugs on a leaf. Yonhap photo

SEOUL, July 26 (AJU PRESS) – On a sweltering summer afternoon, residents of Seoul’s Eupyeong district sought refuge in the shade of a tree. Unbeknownst to them, their respite was shared by an unwanted nuisance: tiny, buzzing critters called lovebugs.

The 12-legged insects fly around in pairs while mating. Known to prefer white over black, they latch onto brightly colored clothing. Attracted to exhaust fumes, they often dive into vehicles, causing car corrosion.

“The bugs were rampant from mid-June to the end of the month. A total of 982 complaints about lovebug outbreaks were submitted during that period, just in our district,” a district official said.

Lovebugs are among about 2,000 alien species currently documented in Korea. While the insects may be a minor annoyance, some invasive species pose significant threats to the nation’s ecosystems.

American bullfrogs are clogging rivers and streams, citrus flatid planthoppers suck juices from fruits, contaminating them with sooty molds, and bur cucumbers are choking out native plant species.

Bur cucumber, an invasive plant species, entangles around indigenous plants, choking them to death. Courtesy of the National Institute of Ecology — Bur cucumber, an invasive plant species, entangles indigenous plants, choking them to death. Courtesy of the National Institute of Ecology

Among the most problematic is the red-eared slider turtle. Introduced in the 1970s as pets and for religious purposes, the animals are thriving without natural predators. Their dietary habits pose a significant threat to local freshwater species and they may also transmit diseases such as Salmonella to humans.

A photo of a red-eared slider and its eggs. Aju Press — This photo shows a red-eared slider and its eggs. AJU PRESS

A 2019 video showing scenes of hunting and cooking the turtles has attracted more than 4 million views on YouTube. In the video, a masked man known as U.M.A, carrying a hand plow and a plastic container, scours marshes in Ansan, south of Seoul, searching for turtles and their eggs, which end up in his meat soup.

UMA a YouTuber with nearly one million subscribers catches and eats red-eared sliders in his video of Catch and Cook WORLDS MOST INVASIVE TURTLE Red Eared Sliders uploaded July 13 2019 Captured from video — U.M.A., a YouTuber with nearly one million subscribers, catches red-eared sliders in this image captured from a video he has uploaded on YouTube.

One of the more insidious threats is the nutria, a large rodent that has been entrenched in Korea’s wetlands for over 30 years. The rodents initially fed on crop seedlings but have since developed their own food sources, which has led to the destruction of marshes. They dig deeper dens, making them more difficult to capture. The number of nutrias captured has remained relatively constant over the past five years.

Experts say nutria or Myocastor coypus now have fully adjusted to living in Korea Courtesy of the National Institute of Ecology — This photo shows a nutria. Courtesy of the National Institute of Ecology

The Nakdong River Basin Environmental Office placed bounties on nutrias starting February 27, offering 20,000 won ($15) per rodent.

“We have caught 873 nutrias as of May. We plan to continue the project until the end of 2024, as long as the budget permits,” an official said.

Experts are calling for measures to prevent dangerous species from entering the environment, including stricter import regulations.

Sung Min-gyu, a researcher with the Biodiversity Foundation, suggests that the nation should adopt import restrictions similar to New Zealand's “Whitelist,” which limits the entry of potentially invasive species.

“Some U.S. states have approval systems for alien species pets. Such systems could greatly reduce the chances of foreign species being released into the environment,” Sung added.

Baby leopard mandarin fishes being released in to the wild July 15 2024 Courtesy of Cheongju City — Residents in North Chungcheong Province release baby leopard mandarin fishes into waters on July 15, 2024. Courtesy of Cheongju City

Local governments across the country are employing various strategies to combat invasive species, including public participation events, professional extermination campaigns, and the release of native predators.

On July 15, authorities in North Chungcheong Province released about 8,400 baby leopard mandarin fish into local waters. Known as apex predators in Korean freshwater ecosystems, mandarin fish prey on invasive species such as largemouth bass and bluegills.

American bullfrogs, or Lithobates catesbeianus, are often used as ingredients for herbal medicine in Korea.Courtesy of the National Institute of Ecology — This photo shows an American bullfrog. Courtesy of the National Institute of Ecology

Another pressing question for policymakers is how to dispose of invasive animals captured or killed during eradication efforts. While some species, such as American bullfrogs, have found use in traditional medicine, most do not have practical applications.

In South Chungcheong Province, officials attempted to make fish cakes from bigmouth bass and bluegill in 2021. However, the project was discontinued the following year due to logistical issues that made it difficult to obtain fresh bass and bluegill suitable for human consumption.

Largemouth basses exterminated in 2023 Courtesy of North Jeolla Province — This photo shows largemouth basses captured in 2023. Courtesy of North Jeolla Province

Some environmental offices have chosen to distribute captured bigmouth bass and bluegill for processing into liquid manure or animal feed. However, since this process is generally outsourced to private companies, the lack of clear guidelines and monitoring has raised concerns about potential misuse or profiteering.

"As far as we know, there are no guidelines restricting the disposal of these species," a spokesperson from the Geum River Basin Environmental Office said. "Instead of simply discarding the fish, we distribute them to those who can make use of them."

Red crayfish an invasive species is found in large numbers in North Jeolla Province Courtesy of North Jeolla Province — Red crayfish, an invasive species, are found in large numbers in North Jeolla Province. Courtesy of North Jeolla Province

Even the Ministry of Environment, which released a manual on invasive species management in 2020, admitted to a lack of specific procedures for processing captured animals into fertilizer or feed.

“We provided examples of how to dispose of exterminated creatures, but we are not aware of specific procedures for processing them into manure or feed,” a ministry official in charge of invasive species said.

The treatment of invasive species also raises ethical questions, necessitating a balance between ecological concerns and animal welfare. Researcher Sung Min-gyu highlighted the legal constraints on handling captured animals.

"It is forbidden by law to transport invasive species to facilities equipped for euthanasia. Killing alien mammals on-site violates the Animal Protection Act," he said.

While some alien species may not cause significant harm, Korea's capacity to forecast their ecological impacts lags behind that of countries like the U.S., which could lead to errors in regulating these creatures, he added.

Kim Dong-young davekim0807@ajupress.com

From lovebugs to nutrias: Korea grapples with growing threat of alien species

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