3 days ago
Swarms of midges plague Osaka Expo site
Midges have crashed the party at the 2025 Osaka Expo.
Chironomid midges, which closely resemble mosquitoes, have been found swarming in huge numbers across the site. While they are not directly harmful to humans, they are annoying visitors.
The Japan Association for the 2025 World Exposition has almost identified where the insects are coming from, but the reason for their explosive increase remains unknown.
The Osaka Expo organizer has sought the help of an insecticide manufacturer and others to find a quick solution.
According to the association, the midges tend to be active in the evening and later at the venue, often appearing on the roof of the event's iconic Grand Ring, and in and around waterside areas.
Since midge outbreaks tend to occur in brackish waters, the organizer believes that the midges are emerging in the venue's Water Plaza and the Sea of Connections areas.
The organizer plans to set up a committee including experts to draw up an insect control plan.
Although chironomid midges do not suck blood, they may cause allergies in humans who inhale their remains, according to the organizer.
On Wednesday, visitors were seen swatting away the pesky insects while strolling around the venue on Yumeshima, an artificial island.
In hopes of eradicating the midges, Osaka Gov. Hirofumi Yoshimura has asked major Japanese insecticide maker Earth for help.
The company has provided the venue with related products, including the Mushi Konai Earth insect repellent. It and the organizer have also conducted a field survey on the midge outbreak.
As the number of visitors is expected to increase toward the end of the event in October, keeping the midge infestation at bay is a pressing issue.
In a statement released this week, the association said it will "take immediate measures against the chironomid midges to ensure that visitors can enjoy a pleasant day at the Expo site."
