There are twelve species of cockroach, however, the most common in the UK are the german cockroach and the oriental cockroach. The adult

german cockroach (also known as the steamfly) is 10-15mm long, yellowish brown in colour with two longitudinal dark marks. The wings are well

developed. They can climb rough and polished vertical surfaces. The adult oriental cockroach (also known as the black beetle) is 20-30mm long,

dark brown/nearly black in colour. The males have wings which cover two thirds of the abdomen, the females do not have developed wings. They

can climb rough vertical surfaces, but not smooth.

The nymphs (young) of all species are similar in appearance to the adult but smaller. Immediately after hatching the nymphs are white, but the

cuticle soon darkens to the normal colour.

Cockroaches are nocturnal and are most active at night. Any sudden light will cause them to scurry for shelter. The german cockroach prefers

warmer, humid environments, while the oriental cockroach is frequently found in cooler, less humid areas such as basements and drains.

Life Cycle

Both the german and oriental cockroaches lay eggs which emerge as nymphs. The nymphs pass through a series of moults to reach maturity. The

german cockroach reaches maturity in 4 months whereas the oriental cockroach can take up to 2 years depending on temperature.

Effective control of cockroaches can be complex and treatment must be tailored for the species concerned for it to be effective.