Japan Experiences Sharp Increase in Hornet Attacks Linked to Climate Change

A recent surge in hornet attacks throughout Japan during the autumn season has been attributed to climate change, according to experts.

Unusual Incidents

Besides the typical cases of people being stung, there have been several unusual incidents, such as dozens of runners being stung during races. Shockingly, even a wasp exterminator wearing protective gear was killed by a hornet.

Impact of Rising Temperatures

Experts argue that the rising temperatures caused by climate change have resulted in hornets starting their nest-building activities earlier than usual. This has led to the formation of larger nests and more aggressive worker wasps.

Hida-Kuraiyama Trails Competition

In a distressing incident during the Hida-Kuraiyama Trails competition held in Takayama, Gifu Prefecture, 42 runners were stung by hornets. Eleven of them required hospitalization, including three male runners who displayed severe respiratory symptoms.

Organizers of the race discovered a hornet’s nest near the course, and it is believed that the vibrations or noise from the runners may have provoked the hornets.

Ekiden Race Canceled

In a separate incident in Kokonoe, Oita Prefecture, 22 high school runners were stung by hornets during practice. As a result, the ekiden long-distance relay race scheduled for the following day had to be canceled.

Exterminator Fatally Stung

In Tateyama, Chiba Prefecture, a pest control professional wearing protective gear was fatally stung while searching for a hornet’s nest. Despite his full-body protective clothing, the man was stung multiple times and succumbed to the venom.

Understanding Hornet Behavior

Hornets are known to intensify their nest-building activities from July to October, with autumn being a critical period for raising the next generation of queens. Worker wasps become highly sensitive while protecting the nest and will attack aggressively if they sense a threat to their future queens.

People are more likely to be attacked if they make frantic movements, wear dark clothing, or use strong perfume that attracts hornets. If approached by hornets, it is advised to quietly retreat and avoid swatting at them, as this can provoke a full-on attack from the colony.

Effects of Climate Change

Climate change has had a significant impact on hornet behavior. The nesting period, which usually lasts from late April to October, has shifted forward by about two weeks. This change in timing has resulted in the growth of larger nests and an increase in the number and aggressiveness of worker wasps.

In addition, during extremely hot weather, worker wasps leave the nest to regulate the temperature inside, increasing the likelihood of encounters with humans.

These recent hornet attacks highlight the urgent need to address climate change and its effects on ecosystems and human safety.

(This article was written by Kaede Sano, Shiori Tanabe and Hiroshi Nakano.)