A sudden explosion in the population of so-called “lovebugs,” officially known as Plecia nearctica or red-shouldered march flies, is causing discomfort and frustration across South Korean cities. (Image courtesy of Yonhap)
SEOUL, July 2 (Korea Bizwire) — A sudden explosion in the population of so-called “lovebugs,” officially known as Plecia nearctica or red-shouldered march flies, is causing discomfort and frustration across South Korean cities, with local authorities overwhelmed by complaints and limited legal tools to respond.
The bugs, characterized by their red thorax and black wings, have become a seasonal nuisance, especially in late June and early July. According to the Seoul Metropolitan Government, reports related to lovebugs nearly doubled in 2024, reaching 9,296 from 4,418 the year before.
In Incheon’s Gyeyang District, where swarms were recently spotted near Gyeyang Mountain, citizen complaints rose from 62 last year to around 360 as of June 27.
Experts say lovebugs have few natural predators — a rarity in the insect world — largely due to their acidic body chemistry. Researchers in the U.S., where the species is also common, note that birds, frogs, and even insects avoid consuming them due to their sour taste and tough exoskeleton.
Swarms of lovebugs, officially known as Plecia nearctica, have been reported in areas such as Gyeyang Mountain in Incheon, prompting a surge in related public complaints. The photo shows lovebugs caught on a sticky trap. (Yonhap)
Although harmless to humans in terms of bites or disease transmission, lovebugs are drawing public ire for invading outdoor spaces, clinging en masse to car windshields, and leaving acidic residues that corrode paint and building materials. Their presence near restaurants and cafes has also prompted concerns about lost business and public hygiene.
Despite their disruptive presence, lovebugs are not classified as traditional disease-carrying pests under South Korean law. As such, municipalities face legal limitations in mounting large-scale eradication or prevention efforts. Local pest control typically targets mosquitoes and cockroaches, not nuisance insects like lovebugs.
Some districts have attempted ad hoc responses, such as air gun spraying and water flushing in hard-to-reach areas, but results have been minimal. Vehicles can’t easily access mountain trails like those near Gyeyang, making sustained pest control even more difficult.
On the morning of June 30, the summit of Gyeyang Mountain in Incheon’s Gyeyang District was swarmed with lovebugs (Plecia nearctica), causing discomfort and inconvenience for hikers. (Yonhap)
The Seoul Institute has proposed reclassifying lovebugs as “epidemic urban pests” and expanding pest control policies to include insects that, while not vectors of disease, cause significant public discomfort or stress through rapid population surges.
“Policy must adapt to modern urban realities,” the institute said, recommending that authorities begin to manage insects that either proliferate en masse or significantly interfere with daily life, even if they don’t pose direct health threats.
M. H. Lee (mhlee@koreabizwire.com)
