Hissing Cockroach (Cromphadorhina portentosa)
Forests of Madagascar
Number of Eggs:
There are around 3,500 species of cockroach found throughout the world. It is thought that they originated in Africa, but have ‘followed’ humans around the globe. Today, some species are only found around human habitation. The hissing cockroach, also referred to as the giant cockroach, is found in the forests of Madagascar, living in the leaf litter on the forest floor. They are detritivores, eating a range of decaying plant matter including leaves, bark, fruit and seeds, and therefore play an important recycling role in the forest ecosystem.
Being insects, these cockroaches have three body parts (the head, thorax and abdomen), one pair of antennae, and six legs, ending in hooked feet which give them excellent grip. The antennae are used for feeling and smelling, and those of the males are more feathery than those of the females. This implies that the males have a better sense of smell - the extra featheriness means there is a bigger surface area to detect more scent molecules.
All individuals can hiss, but most often it is the mature males that are heard doing this. This noise comes from the system of tubes through which they breathe - the tracheal system. The tracheae are branching tubes that start at the surface, and get smaller and smaller in diameter as they penetrate deeper into the body of the animal. Eventually these tubes carry the air right down to the individual cells. The hissing noise is made by forcing air out through these tubes and through the spiracles - the holes on side of the cockroach’s body where the tubes end. It is thought that the hissing is useful for communication, intimidation between males, and for frightening off potential enemies.
When laid, the eggs are surrounded by a frothy substance which hardens as it dries. This protective structure is called an ootheca. Female hissing cockroaches take this back into their bodies into a brood pouch until the young hatch after about two weeks. The young nymphs are miniature white versions of the adults. As their soft, white outer covering (cuticle) hardens, it darkens in colour. This process is called tanning.
The hard cuticle does not grow, so the nymph periodically grows a new covering under the old. The old cuticle then splits and is moulted. The new covering is soft and white at first, allowing the nymph’s body to grow. Again the new cuticle will harden to protect the animal. The nymph continues to moult until it reaches adult size (up to three inches - 7.5 cm), when it becomes sexually mature.
About 90% of Madagascar’s forest has been destroyed or damaged, largely due to agriculture. Although hissing cockroaches are very adaptable, their numbers will start to suffer as suitable habitat disappears.
Large, robust insects. Dark brown/black in colour
Hissing cockroaches survive well and breed very easily in captivity. They need a fairly dry environment - at Marwell half their tank is sprayed with water daily, this gives them a choice of moist or dry area. The temperature is also important and is maintained at 70-75F (21-24°C).
They will eat a variety of food and at Marwell are fed on a mixture of fruit, vegetables and various leaves.