On April 18, people gathered to watch a baseball game at Jamsil Stadium in Songpa-gu, Seoul, were attacked by a swarm of insects. The bugs were oriental hoverflies, which mate in May and June. When the stadium lights were turned on around 8 p.m., the swarm grew to the point where it obstructed the view of the players at bat. Kim Mo (30), who visited the stadium from Suwon, said, “The sky looked white as tens of thousands of Oriental Harusal were illuminated above the dome field, and dozens of them fell like rain into the stands.”
Dongyang Harusal, which used to appear in Namyangju around May and June every year, has recently appeared in swarms in Gwangjin-gu, Seongdong-gu, and Gangnam-gu, causing inconvenience to residents and self-employed people. Although it is not a pest that transmits infectious diseases to humans, it is about 5 centimeters long when it spreads its wings and directly attacks humans. In addition, there have been many complaints to local governments due to the foul smell of its carcass.
A window of a convenience store in Deokso, Namyangju, Gyeonggi-do, in May 2020. Oriental day lice are sitting in a group, chasing the light. / Namyangju City
Self-employed people in the Apgujeong neighborhood of Gangnam-gu are also plagued by insects. Swarms of insects, attracted by the nighttime LED lights, have covered the walls of white-painted buildings. Mr. A, who owns a Thai restaurant near Apgujeong Station, said, “We can’t serve outdoor customers at night, and the windows are covered with insects, which greatly hinders our business.” It was also known as the “Apgujeong bug” six or seven years ago.
The reason for the increase in the population is that the water temperature has risen due to rising temperatures, making it more favorable for the larvae to live. An official from Seongdong-gu said, “The Han River basin, which is the larval habitat of the oriental day louse, is a water source protection zone, so it is difficult to disinfect it by spraying insecticides.” “The adult louse lives for only two to three days before dying after mating and laying eggs, so we do not feel the need for disinfection안전놀이터.”
A swarm of Oriental mosquitoes. / Namyangju City
However, experts say that while the increase in the number of Oriental Harusal is inconvenient for residents, it is not a major concern. “The larvae of the oriental harusal are plump and fleshy, so fish like them, so they are used as bait for lure fishing,” said Lee Dong-kyu, a professor at the Department of Health and Environmental Studies at Kosin University. “The oriental harusal is a species that lives in second-grade water or higher, which is an indicator of how clean the environment is,” he said. “Also, their mouths have degenerated, so they cannot bite people or transmit viruses, so they are not pests.”
Local governments neighboring Hangang Park are even passing on tips on how to avoid them. Seongdong-gu said that if you see one near a residential area or on a window, you can spray it with a sprayer. This is because their wings are too heavy to fly when wet.