Cockroaches are nocturnal by nature and spend the day hiding in cracks around areas like sinks, drains, cookers and the backs of service ducts. When switching lights on at night, they may be seen scuttling to safety.
They also emit an unpleasant sour odour, but this is normally only noticeable if the infestation is large. The German cockroach measures about between 12-15mm long and the Oriental cockroach is 17-30mm long.
It is tan to light brown, and has two dark parallel streaks running from the head to the base of the wings. Although it has wings, it is unable to fly. Nymphs have a pale area down the centre of the dorsal thorax.
The German cockroach is one of the most common and prominent household cockroaches in the world and can be found wherever humans live. Cockroaches are often found inhabiting restaurants, food processing facilities, nursing homes and hotel rooms.
The German cockroach has three life stages, known as incomplete metamorphosis: the egg, nymph, and adult. Their entire life cycle is completed in about 100 days. However, factors such as temperature, food, and strain differences may influence the time required to complete each cycle.
Subject to food, water and temperature, German cockroaches breed throughout the year – at an alarming rate.
Under ideal conditions, population growth has been shown to be exponential. A typical infestation may contain only 20% adults, with 80% still in the nymph stages.
The German cockroach, which can climb smooth surfaces:
Adult size: 12-15 mm
Number of moults: 5-7
Development time (Egg to adult): 2-6 months
Length of adult stage: 3 – 6 months
Number of eggs produced per ootheca: Average 30-40
The Oriental cockroach:
Adult size: 17-30 mm
Number of moults: 7-10
Development time (Egg to adult): 6-18 months
Length of adult stage: 3 – 6 months
Number of ootheca produced in female lifetime: Average 5
Number of eggs produced per ootheca: Average 14-18
How they affect you?
Cockroaches can carry gastro-enteritis, dysentery, typhoid and other food poisoning pathogens.
Germs can be spread from the body of the cockroach or from the droppings they leave behind.
Cockroaches will feed on almost anything including faecal matter. Contamination occurs when the cockroaches come into contact with foodstuffs.
Eradication of cockroaches can be complicated to treat and should be carried out by professional pest controller. The reason cockroaches are so difficult to treat is their hiding places are often difficult to reach with insecticides and because they are so efficient at breeding with such a large number of eggs being produced. A planned and comprehensive eradication program is essential.
The first step is to monitor the level of the infestation. Inspections should be carried out at night, when the cockroaches are most active, using a torch with a red filter which will not scare cockroaches. A high standard of hygiene is important in the control of cockroaches and involves denying access to food and water. By removing the usual sources of food and water, cockroaches will increase their search area, looking for new food and water substances which will in turn increase the chances of them taking the pesticides. Inspections should be carried out at night when the cockroaches are most active.
The correct application of an appropriate insecticide in the right areas can make the difference between success and an expensive failure – so Pest ID pride ourselves in getting it right first time.
Many cockroaches and egg cases will be well hidden and so the insecticide must be placed at and around these harbourage areas, taking into consideration the varying development stages.
Even if the infestation seems under control, the program should be completed as planned at weekly intervals until we are sure all egg cases have hatched, failure to do so will result in the infestation coming back.
Cockroaches are potential carriers of diseases such as dysentery, gastroenteritis, typhoid and poliomyelitis. Cockroaches are also a source of allergens which can lead to allergic illnesses such as dermatitis, rhinitis, bronchitis and asthma. Their diet is omnivorous and includes fermenting substances, soiled septic dressings, leather, parchment, faeces, hair and food for human consumption. The food may be contaminated by the mechanical transfer of causative agents of disease from the insect’s body or by transmission in the faeces. Cockroaches foul their environment with droppings, castings and regurgitated food. They can taint materials with their distinctive unpleasant smell.