Madagascar Hissing Cockroach


 


Classification

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Blattaria

Family: Blaberidae

Genus: Gromphadorhina


Species: Gromphadorhina portentosa



Biology

Madagascar hissing cockroaches are large cockroaches (2-3 inches long and 1 inch wide), which are native to the island of Madagascar, off the coast of Africa.


Males look different from females (sexual dimorphism). Males have prominent protrusions on the thorax, which are called pronotal humps. Females have very small bumps or none, with a much smoother thorax. Males can also be differentiated from females by their brushier antennae.

Male and female roaches


Metamorphosis: Paurometabolous (gradual)

Egg, nymph, adult

Females appear to bear living young, but nymphs actually emerge from an egg case called ootheca. In most cockroach species the female drop the ootheca on the ground or deposit and glue it to something. In the Madagascar Hissing Cockroach, the ootheca is retained within the body of the female until eggs hatch.
The nymphs molt six times during the course of their lives. At the last molt they become sexually mature adults. Adults never molt.


Behavior

Males establish territories and defend them from other adult males. Females are gregarious and do not fight.

As their name suggests, the Madagascar Hissing Cockroaches produce a hissing sound. That is accomplished by pushing air forcefully through a pair of modified spiracles, which are small openings through which air is taken into the trachea. Insects have several spiracles arranged along the sides of the thorax and abdomen.

When do they hiss?

  • Defense - to avoid predators and to defend territories
  • Communication - to signal danger, for example
  • Courtship and mating


  • Females and nymphs hiss only when disturbed.


    Importance

    Decomposers
    Important source of food for other animals


    Links


    Madagascar Hissing Cockroach Information Page:

    http://www.uky.edu/Agriculture/Entomology/entfacts/misc/ef014.htm


    Madagascar Hissing Cockroach Care Sheet:

    http://www.petco.com/assets/articles/caresheets/pdf/timadagascarhissingcockroach051503.pdf

    The Hissing Cockroach, Gromphadorhina portentosa:

    http://www.key-net.net/users/swb/pet_arthropod/hiss.htm