Cockroaches


One of the most successful insect species of all time, the modern cockroach has an ancestry dating back as much as 300 million years - cockroach fossils this old have been found which show little difference from modern types. This insect has frequently been described as a 'living fossil', but it is by no means a 'primitive' insect. Rather, in the cockroach Nature has produced an extremely hardy, adaptable and efficient creature which had already achieved its ultimate form while the dinosaurs rose and fell, and the first rat-like mammals scurried around the forest floor. As usual in Australia, the majority of problems are caused by imported pest species of cockroach, native varieties being generally shy creatures which avoid areas of human habitation. Pest cockroaches, thought to have originated in Africa, on the other hand, actively co-habit with humans and have adapted their behaviour accordingly. Indeed their affinity for living amongst humans has made them one major carriers of human disease.
German Cockroach
The most common 'house cockroach' this insect tends to seek out warm, moist conditions with readily available food, and is a major pest in domestic kitchens and commercial food preparation facilities. Hiding during the day in cracks and crevices in furniture and walls, under sinks and in cupboards. They feed on any available organic materials including food crumbs and accumulated grease. Because they prefer to stay close to these areas, sighting German cockroaches in other rooms is often an indication of very severe infestation, and the insect's small size and ability to squeeze into tight places means their numbers may become very large before their presence is even suspected. German cockroaches tend to contaminate food with their droppings as well as transporting disease germs on their bodies. In very severe infestations they have been known to bite and even feed off food residues on the faces of sleeping people, but they are also considered an 'aesthetic pest', with their mere presence in a home carrying a high social stigma.
American Cockroach
Larger than the German cockroach and presenting a somewhat more 'streamlined' appearance, the American cockroach is less often found in the living areas of dwellings, tending to inhabit roofs, under-floor spaces and wall cavities. They tend to prefer decaying matter as a food and for this reason are found frequently around compost heaps and rubbish dumps. Because of their preference for decomposing materials are tend to be prolific carriers of bacteria and have been implicated in the transmission of salmonella, particularly in food preparation facilities.
Australian Cockroach
Australian Cockroaches are mis-named, as they are not native to this continent and originated in Asia. Closely resembling its near relative the American Cockroach although smaller, it is distinguished by the yellowish markings on the front part of its body. They tend to prefer warmer environments and are often found in greenhouses and decaying compost. Although they posess wings they rarely fly and are similar in habits to the German cockroach, causing similar problems. They may also attack clothing and wallpaper.