In general, cockroaches are tropical and live outdoors. However 25 species are found in close association with humans. In Darlington, and the rest of the UK, the Oriental Cockroach and German Cockroach may be found in commercial and domestic buildings.

Oriental Cockroach

The Oriental Cockroach (Blatta orientalis), is a large species of cockroach [external link] with adult males being 18–29 mm (0.71–1.14 in) and adult females being 20–27 mm (0.79–1.06 in) long with a glossy dark brown to black body colour. The female produces an egg capsule that is blackish-brown in colour. Approximately 16 eggs are laid in the egg capsule, arranged in two rows of eight eggs each. An average of at least 14 eggs can hatch per egg capsule. The female may deposit up to 18 egg capsules, with an average of eight per female. Generally, egg capsules are deposited in places where food is readily available. Eggs hatch in about two months. Newly emerged nymphs are very light, but later change to a reddish- to blackish-brown colour. Adults are glossy, with a dark reddish- to blackish-brown colour. The adult females may live from 34 to 181 days.

What do oriental cockroaches eat and where do they live?

Oriental cockroaches are omnivorous, but they prefer to feed on starchy foods. They are less wary and more sluggish than other cockroaches. Their ideal habitat temperatures range is about 20 C. They are typically found in dark, damp basements, areas between soil and the foundation, underneath pavements, in sewer pipes, floor drains and any other cool, moist place.

German Cockroach

The German Cockroach (Blattella germanica) is a small species [external link] of cockroach [external link], typically about 1.1 to 1.6 cm (0.43 to 0.63 in) long varying in colour from tan to almost black. They are found in warm moist conditions.

What do German Cockroaches eat and where do they live?

They are usually "brought in" to buildings on packaging, cartons, handbags, boxes, luggage and furniture brought from places with existing cockroach infestations.

Adult German Cockroaches can live up to one year and prefer to stay close to food and water sources in warm moist conditions. They scavenge for meats, sugars and fatty foods and are usually found in kitchens and bathrooms. Females can produce one egg capsule every 3-4 weeks and carries it until it is ready to hatch. Each capsule contains 25-45 eggs that hatch into 3mm-long black nymphs then progress through six or seven molts before becoming sexually mature,

They are most active at night and if seen during the day, it most likely is due to overcrowding in their hiding places or a shortage of food and water supply.

Using a torch they can be found in cracks and crevices and also behind and under refrigerators / cookers / microwaves and recycling bins.

The German cockroach is very successful at becoming established in buildings because:

  • lack of natural predators [external link]
  • prolific reproduction
  • short reproductive cycle
  • sexual maturity attained within several weeks, and
  • the ability to hide in very small spaces.

What harm can they do?

Cockroaches are present in houses, hotels, restaurants, supermarkets, cruise ships, warehouses and many other places where sufficient food and water are available. They are of public health importance and considered a pest because they can mechanically transmit pathogenic organisms such as salmonella bacteria, and are a source of powerful allergens.

Controlling cockroaches – Pest Control

Insect identification, thorough inspection and assessment of the infestation, is important to successfully managing cockroaches. The cockroach population can be substantially reduced non-chemically by denying food and water, maintaining hygiene, altering the harbourage and installing sticky traps. Maintaining high standards of hygiene involves keeping indoor waste bins clean and regularly emptied, removing food debris from kitchen sink plug hole, keeping all kitchen appliances (cookers, microwaves, toasters, ovens, hobs refrigerators) in a clean condition so that it is food free and grease free, removing food particles from kitchen cabinets, not leaving crockery unwashed where insects can reach, and if you have a pet removing uneaten bowls of pet food.

To be effective pest control measures must be comprehensive, sustained and systematic; survival of just a few eggs is quite enough to regenerate a nearly exterminated pest population within a few generations.

Cockroaches can be eradicated by using chemical products. The Council can provide a treatment to eradicate cockroaches in domestic properties using professional insecticide with trained staff but there is a charge. If you would like to arrange a treatment please telephone Customer Services on 01325 405111.