Seoul gears up to prevent swarms of oriental mayflies

Seoul is proactively implementing measures to prevent the resurgence of swarms of oriental mayflies, which plagued numerous residents last year.

A photo of oriental mayflies in a subway train along the Gyeongui-Jungang Line was shared on X, formerly known as Twitter, on Saturday. [SCREEN CAPTURE]

Seoul is proactively implementing measures to prevent the resurgence of swarms of oriental mayflies, which plagued numerous residents last year.

The Gangdong District Office in eastern Seoul said Friday that it has installed additional insect traps near four parks in Amsa-dong, located by the Han River. An additional 14 traps will be installed near these parks, the district office said. Currently, there are a total of 38 insect traps in Amsa-dong parks.

Oriental mayflies, often referred to as Tinkerbells in Korea, are mostly found around freshwater areas. The bodies of these mayflies measure 18 to 22 millimeters (0.7 to 0.9 inches) in length, and their wingspan is about 50 millimeters. The number of these insects has risen in Korea in the past few years due to the Han River’s improved water quality.

While they do not transmit diseases, they can cause discomfort as swarms of mayflies are drawn to bright lights and can be found outside, in buildings and on public transportation.

A person installs an insect trap near a park in Gangdong District, eastern Seoul. [GANGDONG DISTRICT OFFICE]

Oriental mayflies have already been spotted across the city this month, with numerous photos of them shared online.

Last Saturday, a passenger on a Gyeongui-Jungang Line subway train posted a photo on X showing oriental mayflies on the walls and handles of the train carriage.

The Seongdong District Office in eastern Seoul, which struggled with numerous reports of the insects last May, said it has been turning on the insect traps at parks near the Han River as of this month. The office added that it is responding promptly to any reports filed regarding the appearance of oriental mayflies.

Dimming lights in general and changing white lights to yellow lights can help prevent the mayflies from gathering, according to the district office. Spraying water and using dusting tools can help remove them from windows or other surfaces.

BY CHO JUNG-WOO [cho.jungwoo1@joongang.co.kr]