Australian Cockroaches

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There are 428 species of cockroach in Australia and a number of introduced species have become pests. The two most significant pest cockroaches are the German cockroach and the American cockroach.

Cockroaches live and feed in unhygienic places such as sewers and drains, or feed on garbage that may be contaminated. These insects are cold-blooded and thrive in warm, humid conditions. This is why buildings in the northern parts of Australia are particularly prone to infestations.

However cockroaches will make their home wherever they find food, moisture and shelter.


A population of cockroaches can build quickly if not kept in check. A female cockroach lays between 10 and 40 eggs at a time. On average, the female can lay around 30 batches of eggs in her lifetime. The hatched young look the same as adults, only smaller and without wings. Very small nymphs hatch from the egg capsule and then develop through a series of nymph stage to become adults. Depending on the conditions and type, a cockroach can live for up to 12 months.

Cockroaches will eat almost anything, including paper and leather but prefer vegetable matter. Food left unprotected will attract them. They are nocturnal and like to hide in dark corners or crevices and inside food packages during the day. They are also commonly found in drains, sewers and grease traps. Cockroaches generally don’t each much food, but they will spoil it. This is due to their droppings, unpleasant odours from waxes and fats produced on the surface of their bodies and their tendency to regurgitate food.

It is believed that the cockroach may harbour a range of bacteria including common food poisoning bacteria salmonella, staphylococcus and streptococcus. Ingested bacteria can survive in the cockroach’s digestive system and are passed in its droppings. It is thought that disease is then transmitted to humans when eating food contaminated with cockroach droppings.


Further Information available from the Pests and diseases Image Library on cockroaches.  Click on image below to further information. Information taken from the fact sheet from the Stonnington Council in Victoria on Cockroaches. Click on image below for further information.