Madagascar Hissing Cockroach

STATUSLeast Concern

COMMON NAME (SCIENTIFIC NAME)Gromphadorina portentosa

DIETDecaying plant material and fallen fruit, smaller insects and animal carcasses


HABITATLowland rainforests on the forest floor under leaf litter

Madagascar Hissing Cockroach

 Madagascar hissing cockroaches are an insect with a head, thorax, abdomen and six legs.  Two antennae are found on the head and are used to gather information about the environment. The Madagascar hissing cockroach is one of only a few species of cockroach that do not posses wings at any time during their lifespan.  They are also one of the largest species of cockroaches and can grow as large as 10 cm long with males being larger than females.  An exoskeleton covers the body and ranges from dark brown/black in juveniles to a golden brown color in adults.  The heads of the cockroaches always remain black. A short pair of appendages on the last body segment, called cerci, sense vibrations in the air.  Holes called spiracles are located down each side of the cockroach body. These holes allow for air exchange and is how the cockroach breathes. Air can be forced out of these holes by the cockroach to create a hissing noise when the cockroach feels threatened, which is how this species gets its name. Madagascar Hissing cockroaches are sexually dimorphic, meaning that males and females look different. Females have a smooth thorax with smooth antennae. Males have two horn like bumps on the thorax, with hair like projections on the antennae.

Habitat/Range:  The Madagascar Hissing Cockroach is only found on the island of Madagascar located off the east coast of Africa.  Their habitat consists of the lowland rainforests of Madagascar.  They live on the forest floor under leaf littler.

Diet in the Wild:  Decaying plant material and fallen fruit, they also eat smaller insects and animal carcasses

Diet in the Zoo:  Fruit and Vegetables

Predators:  Small mammals such as lemurs

Life Cycle/ Social Structure:  Cockroach mating can occur year-round while the climate is warm. Mating usually occurs at night when the insect is the most active. When a female is ready to mate, she emits a special scent to attract males. They mate tail-to tail and remain this way for 20 to 30 minutes. The female lays her fertilized eggs in a long yellowish egg case called an ootheca. Females can produce up to 30 ootheca in one lifetime, which equals over 750 young! The ootheca will be drawn back in and kept inside the body for at least 60 days, at which time 15-40 cockroach nymphs will emerge. Nymphs are ¼ to ½ inch long and flat, looking much like sow bugs in the beginning. Nymphs stay with their mother for about 6 months after hatching. Nymphs will molt six times in six months, by the ninth month the nymph is sexually mature. After molting any missing legs or other parts will be regenerated.

They live in large colonies, with several smaller colonies within it. Only one male will dominate a territory of several females. If another male tries to enter, the dominant male will push the intruder out of his territory.  The dominant male will stand on his “toes” which is called stilting.  This is a way for males to appear dominant and defend territory.  Males have large, hard horn like bumps on their heads which they use in fights with other males. Females often move between different male dominated territories.

Life Span: Can live up to 5 years (generally 2-3yrs)

Interesting Facts:

  • Female Madagascar hissing cockroaches create and lay an egg sack, but then carry the egg sack inside their bodies after fertilization until they hatch The hissing noise is made by depressing its abdomen and expelling air out of the spiracles with which it uses to breath Hissing is used to communicate during mating, by males to defend territories, and can startle predators, giving the insect a chance to escape.
  • There are over 3,500 species of cockroaches worldwide
  • Cockroaches eat their shed skin when they are done molting

Conservation Messages:  Cockroaches are highly important to the environment.  They are detritivores and recycle leaf litter and decaying material in the rainforest. By eating rotting and decaying plant and animal matter, cockroaches take the vitamins and minerals that are left in those materials and recycle them back into the environment. The trees then use these vitamins and minerals to grow and pass them along to animals that eat them. Without decomposers like the cockroach the trees wouldn’t grow and the animals would have nothing to eat!

What You Can Do: Make sure products you are buying that come from the rainforest were responsibly harvested. Because of deforestation in rainforests, animals that live there have less and less places to live.

Although Madagascar Hissing cockroaches are not found in Pennsylvania you can still help decomposers everywhere by spreading the message that they are not as gross as people believe they are and are actually a very important part of our ecosystem. Since these animals clean up dead and decaying plant and animal matter they are essential in keeping our world clean. Some decomposers like cockroaches are seen as pests, but environmentally friendly methods should be used when trying take care off a pest problem.