Cockroaches are common and hardy insects, and can tolerate a wide range of environments from Arctic cold to tropical heat. They date back to 320 million years ago.
Appearance, life cycle and habits
Tropical cockroaches are often much bigger than temperate species. They are often depicted as dirty pests, though the great majority of species are inoffensive and live in a wide range of habitats around the world.
Australian Cockroach (Periplaneta Australasiae)The adult Australian cockroach is 23 – 35 mm long, it is brown in colour and its head has a sharply contrasting pale or yellow margin. It is very similar in appearance to the American cockroach and can easily be mistaken for it, but it is slightly smaller than the American cockroach. It is an introduced species in Australia and probably originated from Africa. Australian cockroaches prefer warmer climates and occurs outside, often where there are plants, wood piles and under garden litter. They also occur in roof voids and walls. The insect can travel quickly, often darting out of sight when someone enters a room, it is also known to be very mobile as it has wings.
German Cockroach (Blattella Gemanica)The German cockroach is one of the smaller cockroaches, with the adult cockroach measuring 10 – 16 mm. In colour it varies from tan to almost black, and it has two dark, roughly parallel, streaks from behind the head to the base of the wings, but it can barely fly. German cockroaches are usually found in kitchens behind and under stoves, dishwashers and sinks. When they are seen in rooms other than the kitchen, it is likely that the population of the insects is very dense throughout a building.
American Cockroach (Periplaneta Americana)The American is the largest cockroach species, the adult American cockroach being 35 – 40 mm long, with a pale yellow border around the upper area of the thorax. It is capable of flight. They are native to Africa and the Middle East. Despite their name, they are believed to have been introduced to America only from the 17th century. American cockroaches live both indoors and outside depending on conditions. They inhabit wall cavities, roof areas and sub floors and are often encountered around drains and sewers. They are therefore potential spreaders of disease.
Useful tips on cockroaches
Like most animals, cockroaches need food, water and shelter, which they find in most houses and buildings where humans live and work.
The following preventative measures are recommended:
- Eliminate food and water sources. This is achieved by implementing clean-up procedures at the end of each day so that food is not available at night when cockroaches are active
- Use vacuum cleaners to remove food waste from floors and cupboards in kitchens. Wiping may leave residues in cracks
- Keep garbage in sealed containers prior to collection
- Store food in sealed containers and in refrigerators to reduce accessibility by cockroaches
- Heat-treat appropriate food articles in a microwave to kill egg cases before storage in the kitchen
- Regularly inspect the motors of washing machines and refrigerators, electronic controls of microwave ovens, stoves and computers as cockroaches are attracted to warmth and can damage equipment. This may help avoid expensive repairs
- Fill in cracks and crevices in walls and cupboards to prevent cockroach access
- Inspect roof cavities as this can often locate populations of otherwise undetected smoky-brown and American cockroaches