5 Scariest Bugs in Japan

My Top 5 List (I realize that not all are “technically” bugs)

Recently I was asked a question on my YouTube Facebook page about creepy crawly things. Someone who plans to move to Japan shared with me that they are very frightened of spiders and fear they may have an allergy. They wondered if there are many spiders one should fear in Japan.

I think most adults I come across in Japan have a fear of bugs to some extent. When I talk about adults, I am of course referring to both Japanese and non-Japanese. Often that fear seems pretty irrational.

Many people tell me they don’t like insects simply because of the way they look. Also, for many of these “bug haters” there must have been some sort of change in attitude during their lives. I say that because most children I meet like bugs. Catching cicadas, grasshoppers and mantises is one of the most popular summertime hobbies of Japanese children. At some point though, many turn from bug fans to bug fearers!

I am a self-described insect fan. I have been teaching my son not to fear, but enjoy insects. At the same time however, I do realize that there are some dangerous insects in Japan. There are some bugs that no one should touch. I have also been trying to teach my son that as well.

Here is a short list and a little information about some of the most dangerous and freaky insects in Japan (in no particular order):


Japanese Giant Hornet (Suzumebachi):

Found throughout Japan, the giant hornet can be up to 4cm long with a wingspan of 6cm. These are very powerful and aggressive creatures. Pretty much at the top of the food chain in Japan, preying upon almost any other insect out there. In Japan they are known as the osuzumaebachi, which literally translates to “giant sparrow bee.” Although they can be found in cities, they are most commonly found in rural areas.


The giant hornets dismember their victims with their powerful jaws. It is said that their saliva and venom have the ability to dissolve flesh. Their venom is extremely powerful and is injected through a quarter inch stinger. Their sting is extremely painful and requires hospital treatment. They are considered the most dangerous animal in Japan with more than 40 people dying each year of anaphylactic shock after having been stung. Bears kill 0-5 and venomous snakes only about 10 per year.


Japanese Centipede (Mukade)


These fairly reclusive creatures tend to stay in dark, damp places. They can grow up to 20cm in length and are extremely quick and nimble creatures. They are certainly horrifying in appearance when full-grown and are venomous. Bites from a large Japanese centipede are very painful and may cause swelling, weakness or fever. Their bites are normally not fatal, but some people do have allergies to centipede venom.


Assassin Bug (Sashigame)

Assassin bugs can be found in many parts of Japan. They tend to slowly move around on trees and are capable of a clumsy style of flight. Although they seem to normally move slowly, they can quickly strike at their prey.


They use a long “rostrum” (injector) to inject a lethal saliva that liquefies the insides of the prey, which are then sucked out. The saliva contains enzymes that predigest the tissues they swallow. This is very effective when attacking prey that are much larger than the bug itself.

A bite from this relatively small bug can be extremely painful, especially for a child. Although not extremely dangerous to humans, their bite will cause pain and swelling (a really big ouchie).


Caterpillars – various types (Kemushi)

A wide variety of moth and butterfly caterpillars throughout Japan can cause great discomfort if touched. Many have long barbed hairs with mild venom as a defense against predators such as birds and other insects.


If a caterpillar has long hair, bright colors or both, it’s a good rule of thumb to not touch. It can be difficult to remove all of the barbed hairs from one’s skin and the venom cause pain and itching.

At certain times of year, mainly spring, various types of caterpillars fall out of trees on the ground. This can sometimes be treacherous for hikers trudging through the woods. I have had friends who have suddenly felt pain and realized a caterpillar fell down the neck of their shirt or on their shoulder.


Huntsman Spider (Ashidaka-gumo )

The Huntsman gets its name from its speed and the way it hunts. They are also sometimes known as crab spiders because of their size and shape. They tend to prefer living in woody places such as the forest, woodpiles and wooden shacks and buildings. They also can live under rocks and large pieces of tree bark.


Full-grown male spiders can have a diameter (legs) of 10-12 inches, about the size of a dinner plate. Some people confuse them with tarantulas because of their appearance.

The Hunstman spider does have venom that it uses to immobilize its prey. They have been known to inflict defensive bites that are quite painful and lead to swelling, but their venom is not normally considered dangerous to healthy humans. They are often considered beneficial since they feed on insect pests such as cockroaches.

So there you have it. Not all of these are technically insects (six legs, 3 body parts – abdomen, thorax and head – 2 antennae), but they fit into the “creepy crawly” zone nonetheless.

(This post was originally published August 23rd, 2013)



Kevin O’Shea is a Canadian PYP (elementary school) teacher at an international school in Kobe, Japan. He is a podcaster, birder and insect enthusiast.

Check out his Birds of Kansai Facebook page for lots of great nature photography and information about wildlife and the beauty of Japan and of course the Just Japan Podcast.

Follow him on Twitter: @jlandkev



  1. Nope. Just…
    Real glad there aren’t that many crazy bugs and crawlers in Northern Norway, first time I’ve been grateful for the harsh climate over here.


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