"Ugh, it's disgusting!"
A field experiment to reduce the population of lovebugs (Plecia nearctica) that blanketed Gyeyang Mountain in Incheon last summer and caused significant public distress is set to begin. The National Institute of Biological Resources is launching a full-scale effort to prevent mass outbreaks by targeting the larvae stage.
According to the National Institute of Biological Resources on the 16th, an outdoor field experiment using microbial pesticides to reduce lovebug larvae will be conducted on May 22 near the summit of Gyeyang Mountain in Incheon.
The field experiment will cover nine zones measuring 30m×30m each, focusing on verifying how effectively the larvae population can be reduced. Equipment installation will be completed on May 21, the day before the experiment, in cooperation with Incheon City and Gyeyang District.
The pesticide being used is an eco-friendly microbial agent utilizing Bacillus bacteria. Unlike chemical insecticides, it is designed to affect only fly larvae without harming plants, minimizing environmental damage. In laboratory tests conducted last October, the agent achieved a 94% larval mortality rate within 48 hours of application.
If the field experiment confirms the pesticide's effectiveness and environmental safety, the institute plans to begin the biocidal product registration process. The institute is also implementing a stage-specific response strategy distinguishing between larvae and adults. Larvae control will be the focus until early next month, while large traps using lighting and attractants will be installed to reduce the adult population during their active period from May to July. These traps are scheduled to be installed at the Gyeyang Mountain summit after mid-May.
Lovebugs are known as beneficial insects — larvae decompose organic matter such as fallen leaves, while adults serve as pollinators. However, their mass emergence in the Gyeyang Mountain area last summer caused significant discomfort to hikers and nearby residents, becoming a social issue.
Related complaints have surged, particularly in the Seoul metropolitan area. The number of lovebug-related complaints filed in Seoul more than doubled from 4,418 in 2022 to 9,296 in 2024. Experts attribute the rapid increase in urban lovebug populations to rising temperatures due to climate change combined with the insects' attraction to light.
"The lovebug control effort that emerged as an issue last summer will be pursued in earnest this year starting from the larvae stage," a National Institute of Biological Resources official said. "We will work with local governments to ensure residents are not continuously inconvenienced."
