Except in houses, these cockroaches are common in food companies, bakeries, hotels, restaurants, hospitals, laundries etc. in large numbers. They spread an unpleasant smell that is also absorbed by the food; the smell is caused by the secretion product of a back gland.
Oriental cockroaches (also referred to as the water bug) are omnivores and feed on our food, however they can also survive by eating dead animals, droppings and waste. Cockroaches can be carriers of bacteria and mites. They can also transmit certain diseases because they come into contact with all kind of dirt. Their presence in the immediate vicinity of people is utterly undesired. In the tropics, they are a cleaning crew of nature and they also serve as food for larger animals such as birds.
Appearance and lifestyle
An adult oriental cockroach is 20-27 mm long. Their colour is red-brown to black, the larvae are the darkest. Only the male has well-developed wings, but cannot fly. The wings often makes the male lighter in colour. The oriental cockroach doesn’t just live in bakeries, but also in restaurants, hotels, laundries and houses. Its preferred temperature is 20’C – 29’C.
Many cockroach species shun the light, this also includes the oriental cockroach. During the daytime, they hide in dark, war, places: behind the heater, oven or central heater, in kitchen cabinets, heated cellars, wall cracks near hot water pipes, in bathrooms and drains, near aquariums etc. During the night, they look for food via openings and holes along heating and water piping. They don’t stock up, but they feed every night, during which they move very fast. If they can’t find food, they gnaw in paper (books) and leather.
The development of this insect takes fairly long. The female carries the eggs in an egg package (cocoon) which contains about 16, for a maximum of 5 days at the abdomen, before she drops it at a favourable location.
On average, adult females produce about 8 egg packages during their 35-180 day lifespan. About 2-3 months after dropping the cocoon, the wingless larvae hatch, that, via 7-8 moult processes go through a very long development period, of 1-4 years, depending on the circumstances, before they reach adulthood. The transformation is incomplete, meaning that the larvae look like the adult insect (imago) at birth and only differ in size and lack of wings. During the last moult, the wings are fully grown, however for the eastern cockroach this only applies to the males. The egg package is grey-brown, 10x5x3 mm and has a serrated edge at the top, which breaks open as the larvae hatch.
That the temperature plays an important role in the development is demonstrated by the fact that a difference of just several degrees, can accelerate or slow down the development with several months. They are sensitive to cold; a temperature of -4’C for a period of about 15 hours is usually fatal.
The spreading of cockroaches takes place by bringing in frequently used boxes, caskets, crates, containers etc, with luggage and by with moving and transports. In addition to try and prevent the insects from being brought into the area, it can also help to limit the food supply, due to careful hygiene.
Make sure that no food or food residue is to be found in places where cockroaches find their food at night, which usually is the kitchen. Keep food in properly closed dishes, cans, plastic boxes or in the refrigerator. Get rid of food residue and kitchen waste. Carefully seal garbage cans and preferably take them outside for the night. Sealing pipe conduits etc may contribute to limiting the spread of cockroaches in a building.
When planning new construction and the configuration of kitchens, bathrooms, restaurants, bars, hospitals and nursery homes, one should avoid creating ideal shelters for insects. In addition, kitchens of companies and institutions should be situated as favourably as possible compared to the other parts of the building and the food should be stored in a dry cool storage.
Before proceeding with a control action, the extend of the spread of the cockroaches within the relevant building and the adjacent buildings must be investigated. In apartment buildings, the spread first takes place in a vertical direction via pipe ducts etc. Glue traps can be used for this investigation. After this inventory, EWS can proceed to draw up the control plan (order of the treatment, control method to be applied and permitted substances etc) and the information provision to the parties involved. More information is available on our page for cockroach control.
It is recommended to have an expert of EWS check about 6-8 weeks after the treatment whether a post treatment is necessary. The residents/users of the treated areas must be alert to cockroaches after the inspection / treatment and report any detection of them as soon as possible. After the control action has been carried out, one can identify cockroach infiltrations in vulnerable objects such as food companies with glue traps for instance.