Phylum: Anthropoda | Class: Insecta | Order: Blattodea | Family: Blattidae


Economic Importance

  • Cockroaches threaten human health because they transmit or aggravate many serious diseases, including Salmonella, E. coli, food poisoning, asthma, and Hepatitis E, diarrhoea, and dysentery
  • Cockroaches, their shed skins, and their droppings contaminate hundreds of thousands of pounds of stored food every year
  • Cockroaches are one of the most difficult pests to eradicate, due to their adaptability, their ability to quickly become resistant to insecticides, and their prolific reproductive habits


  • Rapid reproduction is one of the reasons why a single pregnant cockroach really can explode into a major infestation in almost no time at all
  • Cockroaches can live 3-4 months with sufficient food, warmth, moisture, and harborage
  • Females produce 4 to 6 oothecae, with each ootheca containing between 30 and 40 eggs. This makes for an average reproductive potential of between 120 - 240 live offspring during her lifetime
  • Cockroaches reach sexual maturity in about 4 weeks for German Cockroaches and 6 months for American Cockroaches under favorable conditions
  • Cockroaches typically are nocturnal insects; they only appear during the day when disturbed or when there is an excessively large infestation
  • Cracks and crevices are favoured hiding and breeding areas

Life Cycle

  • Cockroaches grow and mature by gradual metamorphosis. There are three stages in the life cycle: egg, nymph, and adult. Generations overlap, so all stages may be found at any time of year
  • Females deposit eggs in bean-shaped or purse-like leathery egg cases called oothecae. These are dropped or attached in hidden places by the females shortly after their formation. Oothecae of various species are quite distinctive and may be used as an aid in determining what species are involved in an infestation
  • The nymphs which hatch from the eggs resemble the adults, except that they are smaller, have undeveloped wings, and frequently are of a somewhat different color
  • Nymphs develop rather slowly, growing by progressive stages, each stage terminated by moulting
  • Nymphs may moult 5-13 times before transforming into adults

Cockroach Species

Cockroaches are insects of the order Blattodea, of which about 30 species out of 4500 total are associated with human habitations. Several species are well known as pests

German Cockroaches (Biattella germanica)

  • Adult German cockroaches average about 1.5 cm in length
  • They have long antennae which they use to detect chemicals, moisture, air currents, and probably sound waves and vibrations in their environment
  • They prefer warm, moist areas, and are frequently found in kitchens and bathrooms
  • They are brown colored with two dark parallel streaks running from the head to the base of the wings
  • Female cockroaches carry their ootheca with her during the germination rather than depositing it like other species

American Cockroaches (Periplaneta americana)

  • They are large roaches, ranging in length up to 4 cm
  • They 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 of both sexes have working wings and at least some flight capability, but oddly enough, they seldom fly

Brown-Banded Cockroaches (Supella tongipalpa)

  • They are 1.5 cm in length as adults
  • Adults of both sexes have wings, although only the males fly. Brown-banded cockroaches have two light­ colored bands running across the base of their wings, hence the name "brown-banded cockroach"
  • Compared to other common  roaches (such as the German cockroach} brown-banded cockroaches tend to prefer drier conditions
  • They're commonly found in bedrooms (especially in the cabinets and night tables), in closets, behind peeling wallpaper, and inside electrical and electronic equipment

Brown Cockroaches (Periplaneta brtmnea)

  • Brown cockroaches are large species of cockroaches
  • They are about 3-4 cm long, have wings and are dark, reddish brown in colour
  • The brown cockroaches can be distinguished from American cockroaches by observing their cerci, which are two pointed barbs, or spines, near the posterior end of some cockroaches
  • Brown cockroaches have a pair of blunt, short and dark cerci while the American cockroaches have longer and sharp-pointed cerci

Australian Cockroaches (Periplaneta australasiae)

  • Australian cockroaches are also large species of cockroaches
  • They are winged, can be about 3-4 cm in length, and are dark brown in colour
  • Australian cockroaches are very similar to American cockroaches but can be distinguished by a yellow margin on the thorax and and yellow streaks at its sides near the wing base
  • They normally feed on plants unlike other cockroaches and can also feed on different organic substances including decaying substances

Smooth Cockroaches (Symploce pallens)

  • They are brownish yellow in colour, smaller in size (12-15 mm) compared to German or American cockroaches
  • Adult males have longer wings which may extend till the abdominal tip
  •  Adult females have shorter wings which may cover only one-third of its abdomen

Cockroach Management Program

  • Prevention is the key to successful cockroach control. Preventive measures will minimize cockroach invasion of buildings and eliminate or greatly reduce availability of food, water, and shelter
  • These insects can be discouraged from entering buildings by sealing any cracks of 0.3 cm or more in foundations and exterior walls. The seal around air conditioners ,doors, windows, and other structural openings should be examined to insure that there are no gaps which permit cockroach entry
  • Refuse should be stored in durable, securely covered containers
  • Incoming merchandise such as beverage cartons, groceries, dry cleaned items, luggage,and used appliances or furniture should be inspected for hitchhiking cockroaches and/or their egg cases
  • Inside a dwelling, all cockroach hiding areas and food sources should be eliminated
  • Leaky water faucets and pipes should be repaired
  • Sanitation or cleanup will aid considerably in cockroach control
  • Unwashed dishes, kitchen utensils, and exposed food products should not be left overnight. All spilled liquids should be cleaned up
  • If pets are fed indoors, leftover food should not be allowed to remain in the feeding dish overnight
  • Treat perimeter (outside the property) with an insecticide
  • Cockroaches locate and feed on the bait and carry it back to the nesting area. Bait carried back will kill other cockroaches by coprophagy (excreta) and necrophagy (dead carcasses)
  • Use baits containing a slow-acting insecticide incorporated to a food source attractive to cockroaches