Korea turns to plant extracts to combat urban 'lovebug' swarms

A researcher evaluates the real-world efficacy of a new organic plant extract against lovebugs. Courtesy of National Institute of Forest Science

Scientists in Korea have successfully demonstrated an eco-friendly method to suppress the massive swarms of "lovebugs" that have choked the capital region in recent summers, offering a major breakthrough in urban pest management without resorting to toxic chemical pesticides.

The National Institute of Forest Science said Tuesday that recent field trials utilizing organic plant extracts achieved a 59.3 percent control rate against Plecia longiforceps, commonly referred to as lovebugs.

The findings offer immediate relief to municipal officials and millions of residents across Seoul, Incheon and Gyeonggi Province.

Over the last few years, the sudden, dense emergence of these paired swarming insects has caused widespread headaches. Although entirely harmless to humans and ecologically beneficial as natural decomposers, the insects have routinely coated storefronts, overwhelmed public parks and splattered across vehicle windshields, triggering a deluge of public complaints.

Building on successful laboratory tests conducted last year, researchers shifted their focus to real-world environments this spring to evaluate real-world efficacy. By closely monitoring and comparing treated and untreated zones, scientists proved that a targeted application of organic granules derived from Sophora flavescens — a traditional medicinal plant commonly known as shrubby sophora — could suppress adult insect emergence by more than half.

The institute’s research team emphasized that breaking the insect's reproductive cycle hinges on precise timing. To maximize efficiency, control efforts must happen during the early larval stage, just after the current summer generation's eggs hatch in the soil.

"Our field trials show that eco-friendly plant extracts are a definitive, reliable alternative for halting the spread and regulating the density of these pests," Park Yong-hwan, a lead researcher at the institute's Forest Insect Pests and Diseases Division, said.

Moving forward, the state-run institute plans to conduct follow-up studies to optimize the exact frequency and timing of suppression efforts. The ultimate goal, officials said, is to build a highly efficient, sustainable pest management framework that municipalities can easily deploy to minimize public disruption.

This article was published with the assistance of generative AI and edited by The Korea Times.