Seoul's Insect Crisis Shifts: Lovebug Population Drops as Brown Katydids Surge

The metropolitan landscape of Seoul and its surrounding satellite cities is witnessing a curious transition in its battle against insect infestations. For the past few years, the region was plagued by the sudden influx of 'Lovebugs,' which caused widespread panic and countless complaints. However, recent data suggests a victory for urban pest control, though this relief is short-lived as a new intruder, the Brown Katydid, has begun to dominate the scene.

According to recent reports from the Seoul Metropolitan Government, the number of complaints regarding Lovebugs has plummeted. Figures show that reports dropped to 1,515 this year, a stark contrast to the staggering 9,296 recorded in 2024 and 5,282 in 2025. City officials attribute this success to a proactive and multifaceted strategy. By focusing on the early eradication of larvae, expanding the network of insect traps, and deploying high-tech water-spraying drones, the city managed to break the cycle of the Lovebug swarms, preventing the same level of urban disruption seen in previous years.

Yet, as one nuisance fades, another emerges. Residents in northeast Seoul—particularly around Buramsan and Suraksan—as well as those in Namyangju, Gyeonggi Province, are reporting an alarming increase in sightings of the Brown Katydid, scientifically known as *Paratlanticus ussuriensis*. Unlike the Lovebug, which is primarily a visual and psychological nuisance, the Brown Katydid presents a more physical threat. These insects, measuring between three to four centimeters in length with a deep brown hue and powerful hind legs, have been spotted not only on mountain hiking trails but also infiltrating apartment walls, plumbing pipes, and private residences.

Experts have issued a cautionary warning to the public: the Brown Katydid possesses powerful mandibles. If these insects feel threatened or are handled by humans, they are prone to biting. Consequently, authorities advise citizens to avoid capturing the insects with their bare hands.

Beyond the discomfort caused to urban dwellers, the surge of *Paratlanticus ussuriensis* carries significant economic implications. These insects are indigenous to Korea, but when their populations spike, they transition from harmless residents to 'outbreak pests.' They are particularly voracious when it comes to fruit crops. Orchards located near mountainous regions are especially vulnerable, as the katydids feed on a variety of produce, including peaches, plums, grapes, and apples, potentially leading to substantial harvest losses.

The sudden population explosion is believed to be closely linked to climatic shifts. Research conducted by the Rural Development Administration indicates a strong correlation between rising temperatures and the reproductive success of the species. Specifically, a temperature increase of just 2.5 degrees Celsius can boost the egg-laying rate of Brown Katydids by as much as 58% to 68%. Furthermore, their eggs are capable of remaining dormant for over two years, waiting for the ideal environmental conditions to trigger a mass hatching.

Historically, the damage caused by Brown Katydids was largely confined to specific regions such as Okcheon, Cheongwon, and Boeun in North Chungcheong Province. However, the recent wave of sightings in the Seoul capital area suggests that their activity range is expanding rapidly. This migration into the heart of the metropolis serves as a reminder of how shifting weather patterns can alter the distribution of species, turning a localized agricultural issue into a widespread urban challenge.