Species: Gromphadorhina portentosa
Status: not yet evaluated
Madagascar hissing cockroaches are an insect with a head, thorax, abdomen and six legs. They are 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. Madagascar hissing cockroaches can live 2-3 years.
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 Veggies
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 prenatal bumps on their heads which they use in fights with other males. Females often move between different male dominated territories.
Can live up to 5 years (generally 2-5)
- Female Madagascar hissing cockroaches provision their eggs, then carry them 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
- Over 3,500 species of cockroaches worldwide.
- Four hisses with different social purposes have been identified
Conservation Messages: Cockroaches are highly important to the environment. They are detritivores and recycle leaf litter and decaying material in the rainforest. Explain this to the kids by calling them “natures recyclers”. Expand on this by teaching the students about recycling and asking them what they recycle at home. If the audience is old enough explain about how batteries contain heavy metals and should be recycled if possible. Explain how most cities and towns have a time when they accept electronic devises such as cell phones, lap tops, tv,s, ect. to recycle.
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.
1. Internet. http://www.zoo.org/educate/fact_sheets/roach/roach.htm, http://www.bristolzoo.org.uk/learning/animals/invertebrates/cockroach
2. Gromphadorina portentosa.