The cries of "they're swarming everywhere, it's unbearable" are expected to erupt earlier this year. The red-backed velvet fly, commonly known as the "love bug," is projected to emerge en masse earlier than usual due to higher-than-average temperatures.
◇ First Official Forecast by Forest Research Institute: "Peak from June 15"
According to the National Institute of Forest Science on Wednesday, this year's peak love bug emergence period is expected to run from June 15 to 29.
The forecast was derived using a "temperature-based phenology model" that analyzes changes in insect life cycles according to temperature variations. The prediction drew on 439 observation records from 2023 to 2025 posted on the nature observation sharing platform "Naturing," along with daily temperature data for Seoul, Gyeonggi, and Incheon from January 2022 through May 3 of this year. This marks the first time the Forest Research Institute has issued an official forecast on love bug emergence.
"Analysis shows the emergence timing is about two days earlier than last year's main occurrence period of June 17 to July 4," an institute official said. "The love bug swarms observed last year in Seoul, Gyeonggi, and Incheon are likely to appear earlier this year."
The higher temperatures this spring are behind the advanced timing. Love bugs' growth rate varies with ambient temperature, and warm weather accelerates their development from larvae to pupae to adults.
In particular, this year's occurrence period, centered on the peak activity date (expected June 24), is projected to be shorter than last year, raising the possibility that the "swarm phenomenon" — with individuals concentrated within a specific window — will intensify. The institute anticipates that increased populations could also amplify public inconvenience.
Love bugs are strongly attracted to light, provoking revulsion in residential neighborhoods and urban areas and disrupting outdoor activities.
◇ 300 to 400 per Square Meter at Gyeyangsan Summit
A recent survey of the Mount Gyeyang area in Incheon conducted by the National Institute of Biological Resources and Sahmyook University found that approximately 300 love bug larvae inhabit each square meter in the 300 to 400-meter elevation range near the summit.
Last year, more than 1,500 love bug complaints were filed in Incheon alone, with 31.2 percent (472 cases) concentrated in Gyeyang District, prompting local authorities to act. Gyeyang District plans to minimize public inconvenience this year by deploying specialized equipment including two 3-meter-tall high-altitude traps and 30 bait traps, as well as conducting drone spraying operations and installing sticky traps.
However, love bugs do not bite humans or cause direct damage to crops. A scavenging fly species mainly found in East Asia, including Japan and China, they are classified as beneficial insects that decompose fallen leaves to enrich soil and prey on mites and other pests.
Experts warn that indiscriminate pest control or eradication attempts could instead disrupt ecosystem balance.
