SEOUL — They are dive-bombing pedestrians, carpeting hiking trails and making national headlines.
Known as “lovebugs,” or Plecia longiforceps, this species of invasive march fly is the talk of South Korea’s capital, annoying the public and flummoxing government officials, who are trying to keep these “uninvited summer guests” — as they have been called by the media — at bay.
They are referred to as lovebugs because they are often seen in the act of mating, with males and females attached at the hip as they fly around. They began appearing in the capital area in 2015, and some experts believe they crossed over from southeastern China.
Why their populations are exploding this year is still a mystery, according to Shin Seung-gwan, a biologist at Seoul National University who is researching the phenomenon.
While the media is citing climate change as the reason, Shin says this explanation fails to account for one important detail: They are concentrated in the areas near Seoul, not the warmer regions of the country further south.
“I think, more than climate change, it may have more to do with the urban heat island effect [occurring when a city has much warmer temperatures than the surrounding area],” he said. “But the scale of the current population surge certainly isn’t normal and is something that warrants further observation.”
Lovebugs are harmless to humans; they don’t bite, nor do they carry disease. According to one YouTuber who recently collected a bagful and consumed them in the form of a hamburger-like patty, they are even edible.
“The flavor isn’t A-tier but I think you can eat them,” he said in a video detailing the experience. “They taste like the unique scent they give off in the mountains. They taste like trees.”
Their only sin, as things stand, is arousing disgust.
The only insects more reviled by Seoul residents are cockroaches and bedbugs, according to a survey conducted by local data company Embrain last year. Eighty-six percent of respondents said they viewed them as pests.
Resident complaints about lovebugs to the city more than doubled between 2022 and 2024, from 4,418 to 9,296, according to government data.
So ubiquitous is this loathing that conservative lawmaker Ahn Cheol-soo recently summoned a lovebug metaphor to criticize liberal President Lee Jae-myung’s latest Cabinet-level hire, a former provincial governor who was convicted for his involvement in a political scandal in 2019.
“Much like lovebugs, ex-convicts seem to have a way of sticking with other ex-convicts,” Ahn wrote on social media.
Last year, some argued that the city should officially designate lovebugs as pests — a move that would allow them to be chemically exterminated — citing the threats they posed to mental health. But municipal legislators ultimately abandoned that idea after environmental activists raised concerns about health and safety.
This year, as public patience wears thin, the city is trying a different tack: a PR campaign to gloss up the public image of lovebugs.
“Lovebugs, they aren’t pests! Excessive pest control only ends up hurting the environment and our health and should be avoided as much as possible,” said one animated video posted by the Seoul government’s health department last month.
“Despite their disgusting appearance,” lovebugs provide environmental benefits, too, the video notes: The adults pollinate flowers, while the larvae aid the natural composting of soil.
Although research is still being done into their broader ecological impacts, Shin, the biologist, says that like many invasive species, lovebugs may find their own benign place in the natural order.
“In the process of organisms adapting to a new environment, it’s common for their populations to explode in the absence of natural enemies,” he said. “But over time, those natural enemies or pathogens appear, and their population density decreases.”
Such was the case for another once-maligned invasive insect: the spotted lanternfly.
Believed to have entered South Korea as stowaways on agricultural imports from southeastern China, they swarmed urban areas and destroyed crops until their populations began stabilizing with the emergence of a natural enemy: a parasitic wasp that kills its eggs.
