The vast majority of telephone calls on household pests fielded by the Shibuya Ward Office’s Public Hygiene Division in 2014 were not about rats, cockroaches or spiders but they involved something with a little more sting in its tail — hornets, wasps and bees.

Of 483 phone calls made to the division last year, 279 were related to problems with hornets, wasps or bees (hachi in Japanese). In contrast, the division received 204 calls in regards to other household pests and 184 calls specifically about rats. Each year, the consultations spike during what employees at the division describe as “hachi season,” the period between May and September when the flying insects construct their nests. The calls reach their peak during the summer months once the nests become larger and more noticeable.

Hachi is an umbrella term that encompasses all varieties of hornets, wasps and bees. To help differentiate the varieties, polistine paper wasps are called ashinaga-bachi, while hornets are called suzume-bachi.

Whereas typical household pests such as cockroaches and spiders are quickly identifiable and easy to get rid of, the sheer number of hachi species and relatively difficult extermination techniques often leave people vexed.

“People cannot usually distinguish what kind of flying insect has built a nest at their home,” says Tsukasa Nishikawa of the Public Hygiene Division. “We listen to their description of the shape and size, and try to help them identify the species.”

While people probably aren’t keen to let hornets, wasps or bees build nests near their homes, the Public Hygiene Division recommends letting nature take its course.

In contrast to gaichū, or insects that cause harm to humans, most hachi are categorized as ekichū, or beneficial insects, that perform valued services such as pest control or pollination. Similar advice is given to people who have spider problems.

Although the insects don’t exactly fit one’s definition of cute, they help get rid of cockroaches and, according to Nishikawa, “let themselves out” as soon as their source of food is gone.

Hachi, likewise, do not bother humans if they are not disturbed, and some species even leave their nest after a year.

If, however, the insect in question is an Asian giant hornet, the division recommends extermination, as stings from these insects can sometimes prove fatal.

The Public Hygiene Division helps Shibuya residents remove nests, typically during the winter months when hornets and wasps have already left their nests.

The division advises residents to keep their properties clean in order to prevent hornets, wasps or bees building nests near their homes in the first place.

For more information about pest control, visit the Shibuya Ward Office’s Public Hygiene Division website (www.city.shibuya.tokyo.jp/todoke/health/kankyo_e/index.html, in Japanese) or contact your local ward office.

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