Madagascar
Hissing Cockroach
Fast Facts
What do they look like?
The Madagascar hissing cockroach is a large species of cockroach, growing up to
three inches long. Their hard outer shell, called an exoskeleton, is shiny and brown,
and their head, legs, and antennae are black. Like other insects, they have six legs
and three body parts – the head, thorax, and abdomen. It can be difficult to see the
head, as it is small and carried beneath the pronotum, the first segment of the thorax.
In males, the pronotum also bears two “horns,” bumps in their hard exoskeleton,
which are used in combat. The females lack these horns, and tend to be a little larger
than males.
How do they behave?
Common Name: Madagascar
Hissing Cockroach
Scientific Name: Gromphadorhina
portentosa
Family: Blaberidae
Order: Blattodea
Madagascar hissing cockroaches are nocturnal, emerging at night to forage on the
forest floor. They are communal and live in family groups with a dominant male
presiding. Although they do not have wings and cannot fly, they are excellent
climbers. These cockroaches also have a symbiotic relationship with a species of mite
which live on the cockroach. The mites consume debris on the cockroach so the
cockroach stays clean!
What’s on the menu?
Madagascar hissing cockroaches are decomposers, eating fallen vegetation on the
forest floor and returning nutrients to the soil. At the Zoo they eat fruit and
vegetables.
How are they born?
Class: Insecta
Range: Madagascar
Female hissing cockroaches will produce around 50 eggs inside an ootheca, a
specialized egg-case around one inch long. This species retains the eggs inside her
until they hatch, at which time she gives birth to live young. When the babies are
born, they are the size, shape, and color of a grain of rice, and will get darker as they
grow. As the juveniles mature, they molt their exoskeleton several times in order to
reach their adult size.
Why are they called hissing cockroaches?
As their name implies, these cockroaches hiss. They do this by forcing air through
holes called spiracles on their abdomen. It is believed that no other insects can hiss in
this way. Hissing is a means of communication used when threatened by predators,
when defending territory, and during courtship.
Habitat: Tropical forests
Lifespan: Up to 5 years in captivity
Conservation Status: Lower Risk
What should you know about them?
Although quite large, hissing cockroaches are not the biggest cockroach species in
the world – Australia’s burrowing cockroach, Macropanesthia rhinoceros, is heavier
and the giant cockroach from the Caribbean, Blaberus giganteus, is longer.
How can you help?
Although their population in the wild is considered stable, their habitat is threatened
by mining and agriculture. You can help by buying wood that is sustainably harvested,
coffee that is shade grown, and produce that is grown locally. These products do not
require the destruction of rainforests to grow crops.