The embankment near the point where Yangjaecheon and Tancheon meet in Daechi-dong, Gangnam-gu, Seoul. On the morning of the 17th, a large drone took off with a buzzing sound. This drone is part of the "Sky Drone Quarantine Team" operated by Gangnam-gu. The target is a swarm of mosquitoes hidden in the woods.
The mission of "mosquito eradication" was assigned to Assistant Deputy Director Lee Sang-yoon of Gangnam-gu. The tank installed on the drone body, which measures 3m on each side and weighs 50kg, was filled with approximately 30 liters of pesticide. When the drone, weighing a total of 80kg, began to be controlled by this assistant deputy director, its four large wings started to spin rapidly, lifting it into the air. It rose 30m within 5 seconds and soon began spraying pesticide from atop a tall tree standing on the embankment. As a result, the mosquitoes hidden behind the leaves startled and sprang out of the tree.
On that day, the highest temperature in Gangnam-gu reached 29.7 degrees. Mosquitoes primarily begin their activity after sunset and hide in cool, damp places like behind leaves during the hot day. If the drone sprays pesticide from above the high trees, it can "eradicate" the mosquitoes resting behind the leaves so they do not emerge into the dwellings in the evening.
◇Mosquitoes hide behind leaves as the sun rises... Pest control with drones from above the trees
According to Gangnam-gu on the 19th, complaints requesting pest control for mosquitoes and other pests have been increasing every year. There were 1,783 cases in 2022, but this increased to 1,893 cases in 2023 and 1,962 cases last year. It appears pest activity has become more rampant due to rising temperatures each year. The time when mosquitoes are active has also gotten earlier. According to the Seoul city government, the number of mosquitoes collected from 55 digital mosquito measuring devices (DMS) surged from 387 in the first week of April to 2,843 in the fourth week.
The mosquito activity index in Seoul's waterfront areas recorded "100" on all days except three from June 1 to June 18. A higher number indicates more vigorous mosquito activity. The mosquito index range of 75-100 means that when staying in one spot for 10-15 minutes, individuals would get bitten by more than five mosquitoes.
To enhance mosquito pest control, Gangnam-gu established the "Sky Drone Quarantine Team" in May of last year and was the first among Seoul's autonomous districts to utilize drones. Using drones allows for pesticides to be dropped into mosquito "hideouts" like puddles and dense foliage by rivers, which are difficult for people to access. The pesticide used is "pyrethrin," extracted from chrysanthemum, which has minimal ecological impact and low toxicity to humans.
This assistant deputy director explained that drones are also effective in controlling larvae, specifically mosquito larvae. A female mosquito can lay between 100 to 700 eggs at once. The larvae inhabit puddles formed by rainwater or wetlands along rivers. This assistant deputy director manipulated the remote control to direct the drone to areas by Yangjaecheon where water is pooled, guiding it to fly low while spraying pesticide. It is an area difficult for a person to walk into.
This assistant deputy director noted, "In areas where pest control was conducted with drones, the mosquito density was on average 27% lower than in areas without. The drone can fly for about 8 minutes at a time and can spray pesticide over an area of approximately 1,600㎡ (500 pyeong). On this day, two batteries were prepared, capturing mosquitoes over an area equivalent to around 1,000 pyeong, like a school playground. The drone pest control target for this year in Gangnam-gu is a total of 360 operations, covering an area of 200,000㎡ (65,000 pyeong).
◇Incheon, using drones for mosquito control since 2021... Dongjak-gu in Seoul utilizes tricycle motorcycles
The drone mosquito control initiated by Gangnam-gu is the first among the 25 autonomous districts of Seoul. In the entire nation, Incheon Seogu, which started in 2021, is the fastest. Incheon Seogu deployed four drones to spray pesticides in forested and riverside areas, as well as in regions under development for malaria prevention. They plan to continue drone pest control until October this year.
Seoul Jung-gu has been operating a "Mosquito Control Special Task Force" since April. When residents request via text message, mosquito control operations are conducted at major mosquito habitats like drains and roadside gutters. Dongjak-gu employs tricycle motorcycles for mosquito control in areas where vehicle access is difficult, such as parks, mountain slopes, and alleys. In Yongsan-gu, a professional disinfection company visits dwellings where mosquito occurrences are high to provide consulting.