hissing cockroach

Gromphadorhina portentosa

Common name

hissing cockroach


It is found in the lowland tropical rainforests of Madagascar, usually under dead tree trunks, on the jungle floor, or in areas in contact with humans in landfills.








60-70 days

Number of offspring




They are detritivores, generally feeding on remains of plant matter, including fallen fruit due to its easy availability, they also feed on smaller insects and the bodies and remains of other animals.


2-5 years

Biology and behavior

Relatively little is known about the behavior of these insects in their natural state. They do not have wings and are sexually dimorphic. The main difference is that males have protuberances on their thorax that resemble horns and their antennae are hairier.

They are passive and very docile animals, they are not very active and they are nocturnal. They are sociable, they live in groups or colonies in which males tend to establish territories that they defend from other males, through postural behavior, they do not usually hurt each other. Females are gregarious and do not usually fight among themselves or with males.

The development of the eggs lasts about 2 months. Once the female is pregnant she remains that way for life, and she will be having babies without needing to be fertilized again.

They are false ovoviviparous, that is, the nymphs are born from an ootheca, which remains inside the mother until the moment of birth. From 15 to 40 cockroaches the size of a small melon seed are born from an ootheca.

Some release the ootheca before the nymphs are ready to hatch if they feel stressed. The nymphs are miniatures of the adults and white in color. When they come into contact with the air, the exoskeleton hardens and turns brown. As they grow, they shed their exoskeleton.

They have 6 molts and reach the adult stage in the seventh molt in approximately 10 months, but their growth is faster in warm climates. The nymphs eat the remains of the ootheca as their first food, and later they can eat the same as the adults.


The characteristic hiss is produced by pushing air strongly through modified spiracles. It is a typical behavior to avoid predators. While it whistles, it hides its antennae and head under its thorax, so that it looks like the head of a larger, noisier animal. This whistle is also used as communication to warn of danger, during the males' fights for territory, during courtship and mating. Females and late-stage nymphs only hiss when disturbed or frightened.

African savanna
Equatorial jungle
Madagascar Island