The allure of the Madagascar giant cockroach
August 29, 2026
The Madagascar giant cockroach, exhibited in the "Aye-aye Forest" in West Garden of Ueno Zoo, is one of the world's largest cockroaches, inhabiting the island of Madagascar, located east of the African continent. Adults can grow up to approximately 7 cm in length, making them larger than a typical Japanese Japanese Rhinoceros Beetle.
*The lighting is dimmed during exhibition hours.
The Madagascar hissing cockroach does not have wings. While you might imagine cockroaches as being able to fly with wings, wingless cockroaches are actually not uncommon.
In addition, there is a distinctive feature that is not easily noticeable like wings, but is not commonly seen in other cockroaches. That is, they make a "hissing" sound when they sense danger, when males fight with each other, or when males are trying to attract females.
Because of this characteristic, they are called "hissing cockroaches" in English. The sound is produced when they forcefully push air out through tiny breathing holes called "spiracles" located on the sides of their bodies. The spiracles function like a human nose and mouth, and they take in air and breathe through them. If you're lucky, you might hear the hissing sound at the exhibit.
There are also differences in the thoracic protrusions between males and females. Males have prominent horn-like protrusions on the dorsal side of their thorax. Females, on the other hand, have smaller protrusions and a relatively smoother body surface. Males use these protrusions to compete with other males for food and females to mate with. When you visit the exhibit, pay attention not only to the size of their bodies but also to the shape of their thoraxes.
In the wild, the Madagascar hissing cockroach feeds on a variety of things, including fallen leaves and decaying wood. In zoos, they eat almost anything, so they are given cabbage leaves, monkey pellets (artificial feed), and insect jelly. Organisms that eat and break down almost anything like this are called "decomposers" in the natural world and are important creatures that support the material cycle of the forest.
Cockroaches are often shunned in Japan, but understanding their role in the natural environment and the significance of their physical characteristics might change how you view them.
Take a close look at the Madagascar hissing cockroach and experience its many fascinating features.
[Ueno Zoo West Garden Animal Care and Exhibition Staff]