Cockroaches
There are five main pest species in Australia, all being introduced and forming less than 1% of all 450 species found in Australia. They comprise of: German, Smoky-brown, American, Australian and Brown-banded.
German Cockroach
The German Cockroach (Blattella germanica) is the roach that
exterminators are most often called upon to control in the Australia.
Adult German cockroaches average about five-eighths of an inch long.
They have long antennae which they use to detect chemicals, moisture,
air currents, and probably sound waves and vibrations in their environment.
German cockroaches prefer warm, moist areas, and are frequently found
in kitchens and bathrooms. Thousands of german cockroaches can occupy
a single kitchen.
German Cockroaches are the world's most successful and prolific cockroaches because of their extremely fast breeding habits and ability to adapt to almost any environment. They will eat anything that humans do and will also eat wallpaper, curtains, leather and any other organic material. They are always found indoors and tend to stay where food and water are freely available, such as kitchens, pantries and bathrooms, etc. They cannot fly and carry their egg capsules (Ootheca) until maturity, unlike the other pest species.
The adults are 10-15mm long and are tan to medium brown coloured with 2 parallel dark stripes on the head section (Pronotum). The nymphs are very small, dark and beetle-like when they first emerge from the capsule and within a few weeks grow more slender and lighter coloured. They have a light stripe down the centre at this stage of their development. Signs of infestation include cast skins, dark regurgitation and faecal droppings in corners and door hinges of cupboards. Their droppings are tiny and resemble fly-specks. They are often confused with the Brown-banded Cockroach which is lighter in colour, lives outdoors or indoors in dry environments and can fly.
Life spans for the above five species range from 14 - 84 weeks and can have anywhere from 200 - 20,000 offspring from one female per year.
American Cockroach
American Cockroaches (Periplaneta americana) are large roaches,
ranging in length up to an inch and a half. These are the roaches that
people usually are talking about when they say "You could have put
a saddle on it."
American cockroaches prefer dark, moist, warm areas. They are commonly found
in basements, steam tunnels, boiler rooms, rubble foundations, and similar places.
Often they aren't even noticed until a light is turned on, and they scurry away
rapidly.
Adult American cockroaches of both sexes have working wings and at least some
flight capability, but oddly enough, they seldom fly.
Australian Cockroach
This cockroach resembles the American cockroach and is similar in size to the Smokybrown cockroach. This cockroach is mainly brown and has a yellow boarder around its head. Despite the name the Australian cockroach (Periplaneta australasiae) is originally from Asia. They are winged and may fly. It becomes more active in the summer months and may become more noticeable. They prefer organic food these cockroaches are often found outside or in greenhouses. They can often be found in the same sort of areas as the Smokybrown cockroach.
Smoky Brown Cockroach
This species is similar to the American cockroach but slightly smaller, 3.0-3.5cm in length and slightly wider. It is frequently found in warm humid conditions. The Smoky Brown (Periplaneta fuliginos) usually establishes itself in warm areas of the garden, from where it invades the house. They prefer organic foods, but will eat other food substances and can often be found outside in trees, shrubs and wood. They can be brought inside on pieces of wood or may seek refuge inside during the summer.
Oriental Cockroach
Oriental Cockroaches (Blatta orientalis) are black or very dark brown
in color and roughly an inch in length. Adult males' wings reach about three-quarters
down their abdomens, but they cannot fly. Adult females have only small wing
pads.
Oriental cockroaches tend to live outdoors when the weather is warm, but they
readily move inside during extremes of heat, cold, or drought. They can commonly
be found in garbage storage areas, basements, and under porches and decks. They're
often found along sill plates in unfinished basements and crawl spaces.