OSAKA—Osaka Kansai Expo organizers issued a warning about redback spiders after eggs of the venomous arachnids were found in an area open to general visitors.
In a notice posted on its website on Sept. 11, the Japan Association for the 2025 World Exposition asked visitors to contact staff members if they spot any of the spiders.
According to the association, at least 70 redback spiders have been found in backstage areas accessible only to authorized personnel since the expo opened in April.
Professional pest control contractors have been hired to exterminate the spiders, which are designated as an invasive alien species.
However, a cluster of redback spider eggs was discovered on a table used by visitors on Sept. 9, prompting the association to issue the public alert online.
According to the Osaka prefectural government’s environmental health division, redback spiders become more active during the hot summer months.
While they are not aggressive, they may bite if caught or touched with bare hands.
A bite typically begins with a sharp pain like a needle prick, which then spreads throughout the body.
Symptoms can worsen to include chills and nausea, although serious complications are rare.
If bitten, individuals are advised to rinse the affected area with water and seek medical attention as soon as possible.
AloJapan.com