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'We've never seen a similar species': Rising temperatures bring new bugs to Korea

Published: 03 Aug. 2025, 19:16

A species of frog-leg leaf beetle known as the “tropical jewel insect” [JOONGANG ILBO]

A species of frog-leg leaf beetle known as the “tropical jewel insect” has appeared for the first time in Korea, raising concerns among experts regarding its potential to damage crops and stunt plant growth.

A video posted Tuesday to the TV Creature Encyclopedia (translated) YouTube channel shows dozens of the beetles clustered on kudzu vines along the southern coast of the country.

A 15‑year‑old insect enthusiast who collected specimens during summer vacation said, “I found pupal cases burrowed in the vine’s wood. This species was in Osaka, so I was shocked to see it in Korea.”

The formal Korean name of the beetle, which is native to Southeast Asia, has yet to be established. The YouTube channel called it the “sagra frog‑leg leaf beetle.”

The species could qualify as a significant agricultural pest. The beetles feed on leaves and stems, damaging grapevines and other climbing plants by boring into their vines and inhibiting growth.

While sightings of related exotic insects occurred in Korea in 2012 and 2014 and again in 2021 — as “hitchhiker” species — none have previously exhibited signs of large‑scale infestation or naturalized settlement.

A pupa chamber of a species of frog-leg leaf beetle known as the “tropical jewel insect” larva found along Korea’s southern coast in early July [JOONGANG ILBO]

“We became aware of the species’ presence after it was recently featured on a YouTube channel,” the Animal and Plant Quarantine Agency said. “We plan to conduct a joint investigation with the National Institute of Ecology to assess the extent and spread of its emergence and will coordinate follow-up measures with the relevant agencies.”

Cho Hee-wook, a leaf beetle expert at the Nakdonggang National Institute of Biological Resources, said, “We’ve never seen a similar species in Korea before, so if it has settled here, it could assume an unpredictable ecological status. We’re concerned because we don’t yet know what kind of impact it could have on the local ecosystem.”

The number of subtropical and tropical insect species migrating northwards into Korea is rising.

The yellow-spotted longhorn beetle, a subtropical species, established a presence around Jeju in 2022.

Invasive pests like the Asian subterranean termite and tomato hornworm — native to humid tropical climates — also secured footholds after 2020. Last year, the large moth Theretra oldenlandiae and a type of hawk moth, both native to China and Thailand, established populations in Jeju.

The number of new subtropical insect species rose from 17 to 38 in the past five years, according to the National Institute of Biological Resources.

Scientists attribute the trend largely to climate change.

“Insects, highly sensitive to temperature and mobile, respond visibly to shifting environments,” a National Institute of Biological Resources spokesperson said. “The northward movement of tropical insects reflects the reality of global warming.”

Lim Jong‑ok, a professor of biological and environmental chemistry at Wonkwang University, warned that species that temporarily appear in Korea could survive winter as winters grow milder.

“As the climate crisis continues, fully suppressing ecosystem disruption will become increasingly difficult,” Lim said.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
BY OH SO-YOUNG [[email protected]]