Tens of thousands of dragonflies swarm the Bless, a fishing boat, off the coast of Gimnyeong, Jeju City, Sunday, while anglers were fishing. Courtesy of Jeju Bless

Anglers on a fishing boat off the coast of Jeju Island faced an unusual challenge when a massive swarm of dragonflies descended on them.

According to the captain of Jeju Bless, a fishing boat, tens of thousands of dragonflies started swarming around midnight on Sept. 8 while the boat was fishing off the coast of Gimnyeong, Jeju City.

The swarm covered the entire boat for over two hours, clinging tightly to the bodies of around 10 anglers and causing significant discomfort.

Lee Dong-hyun, the captain of the Bless, said, "When we use lights for night fishing, insects often gather, but I've never seen anything like this. Thousands, tens of thousands came all at once, and it was overwhelming. The dragonflies stuck to our faces and bodies, making it impossible to fish properly."

The Bless, a fishing boat, is swarmed by dragonflies off the coast of Jeju City, Sunday. Courtesy of Jeju Bless

The dragonflies were identified as wandering gliders, about 4 centermeters in length, typically seen from April to October.

Though common in Korea, they are known as global wanderers due to their long-distance migrations. Being subtropical, they prefer warm weather and usually migrate to the southern regions in autumn, but recent abnormal heat conditions are thought to have kept them in Jeju through September.

Tens of thousands of dragonflies inundate the Bless, a fishing boat, while it was engaged in fishing off the coast of Jeju City, Sunday. Courtesy of Jeju Bless

An expert said, "Dragonflies are not harmful insects, so their migration isn't a major concern. However, if hot and humid weather continues, the dragonfly population could increase, and it is unusual to see such a large-scale migration in Jeju in September, so continuous monitoring is needed."

This article from the Hankook Ilbo, a sister publication of The Korea Times, is translated by a generative AI and edited by The Korea Times.