Why "Autumn Monsoons" Make Mosquitoes Worse: Adults to Attack in 2 Weeks

On September 2, after rain fell for three consecutive days in Seoul and finally stopped, a collection of mosquitoes captured by downtown mosquito surveillance equipment was carried out.

[Kang Hyojung / Researcher, Sahmyook University Institute of Environmental Ecology: (You can see mosquitoes flying around here right now?) Yes, that is correct. Looking at them now, those with a yellowish color are likely to be of the Culex pipiens group.]

Even in just over 10 minutes, mosquitoes swarmed here and there.

[Two of them landed right here.]

The collected mosquitoes were transferred to a laboratory for analysis.

[Kang Hyojung / Researcher, Sahmyook University Institute of Environmental Ecology: They are house mosquitoes. They are species that can be frequently seen indoors.]

On September 4, the number of mosquitoes captured across 55 equipment sites in Seoul averaged over 51 per site.

This is a 1.5-fold increase compared to a week ago.

Mosquitoes are cold-blooded animals whose spawning and activity become most vigorous when temperatures are around 25°C (77°F). As autumn temperatures rise due to climate change, autumn mosquitoes are showing a trend of increasing over time.

Back in 2015, mosquitoes were overwhelmingly abundant in August, but starting in 2018, September mosquitoes surpassed August mosquitoes.

Particularly this year, puddles dried up due to heatwaves and droughts, which initially reduced mosquito spawning in early August. However, precipitation increased after mid-August, leading to an increase in spawning as well.

This is because rainwater pooled in various places, creating breeding grounds for mosquitoes.

When mosquitoes lay eggs in these puddles formed after the rain, they grow into adult mosquitoes two weeks later, increasing the overall population.

As the so-called "secondary monsoon" ended this week, the mosquito population is likely to increase further.

[Kang Hyojung / Researcher, Sahmyook University Institute of Environmental Ecology: (In past years as well) as the heatwave subsided and temperatures dropped slightly, mosquitoes showed a trend of gradual increase. (This year) I think mosquitoes will likely increase around the mid-to-late part of September.]

Simply getting rid of stagnant water around the house on a regular basis to block the environment where larvae can grow helps reduce the mosquito population.

(Reported by Han Seong-hee | Produced by Lee Se-young | Camera Footage by Yoon Hyung | Video Editing by Kim Yoon-seong | Produced by SBS Digital News)
※ Please note: This article was translated by AI and may contain errors.