Cockroaches
Order: Dictyoptera
Common Cockroaches in the UK:
Periplaneta americana - American Cockroach
Blattella germanica - German Cockroach
Periplaneta australasiae - Australian Cockroach
Blatta orientalis - Oriental Cockroach
Periplaneta americana - American Cockroach
P. americana is commonly found in association with man in areas where food is prepared and stored, such as restaurants, bakeries, and grocery stores. They also occur in sewers, drains and ventilation systems, but they like warm humid environments, which is why they are commonly found in kitchens.
P. americana are 35 - 40 mm long, reddy-brown to chocolate brown, with fully developed wings which extend beyond the abdomen. They can fly in certain conditions, but only for short distances. These cockroaches are easily distinguished from other species by the colouring of the pronotum which has a buff coloured sub-marginal pattern.
The female makes medium sized dark brown oothecae which she carries around with her for 24 hours before depositing, and gluing it in a safe harbourage. Each ootheca contains approximately 16 eggs. Once hatched the nymphal cockroaches moult 7- 13 times over 5 to 15 months depending on temperature and availability of food.
Blattella germanica - German Cockroach
The German cockroach originated in North East Africa but is now a cosmopolitan pest. It is commonly found in warm and moist areas such as kitchens, bakeries, restaurants and rubbish dumps.
B. germanica is one of the smaller domestic cockroaches ranging from 10- 15 mm long. They are pale browny yellow with two longitudinal darker brown markings on the pronotum separated by lighter bands.
They are winged in adult forms and mate within 7 to 10 days of moulting to adults. Once mated the female forms an ootheca, which she carries with her until just before hatching. Each ootheca contains 37- 44 eggs with 90% of these hatching to first instar nymphs. There are 5 - 7 nymphal stages depending on food, temperature and humidity. The less food available then the slower the insect grows, therefore requiring more moults to reach the adult stage.
Periplaneta australasiae - Australian Cockroach
P. australasiae is found in similar conditions to that of P. americana . They also like warm, humid environments and are often found in kitchens, restaurants, bakeries and food storage areas. Ideally they prefer to be in warmer areas than P. americana but will survive in slightly cooler areas.
P. australasiae is very similar in appearance to P. americana except for a lateral pale yellow stripe on the each of the forewings which is about a third of the length of the wings. They are also slightly smaller, 27- 33 mm long.
The female lays a black ootheca about 10 - 11 mm long which contains about 22- 24 eggs. Once hatched the nymphs moult 6- 12 times depending on food, temperature and humidity.
Blatta orientalis - Oriental Cockroach
B. orientalis is commonly found both indoors and outdoors where there are dark, damp places which are cooler and less humid than the areas favoured by other cockroach pest species.
They lack the areola pad between the two tarsal claws and so find it hard to climb vertical surfaces, they are therefore more commonly found at ground level in basements, cellars, and kitchens around hot water pipes, ovens, sinks, and behind radiators. Outside B. orientalis are found in damp leaf litter, woodpiles, drains and sewers.
B. orientalis is a large cockroach about 20 - 27 mm long, reddish brown to black, with reduced wings and so are unable to fly. Females deposit large oothecae (egg cases), about 10 - 15mm long, in debris, or harbourages to protect them from damage and discovery. Once hatched the nymphs go through 8 to 10 moults before becoming a mature adult. Each nymphal stage is a miniature version of the adult stage except they lack sex organs, and therefore the ability to reproduce, and they have no vestidual wings.
Supella longipalpa - Brown Banded Cockroach
S. longipalpa is commonly found indoors and outdoors, they will infest whole buildings as opposed to smaller areas such as kitchens which the German cockroach, Blattella germanica , frequently inhabits.
This cockroach builds harbourages in furniture, bedding, cupboards and other nooks and crannies that are warm and in elevated positions. They are good climbers and will deposit their ootheca (egg cases) on ceilings, shelves and all types of furniture. They are also attracted to televisions, toasters and other electrical appliances. These cockroaches will readily feed on cardboard, wallpaper paste, gum and other starchy materials.
S. longipalpa is a small cockroach similar in size and appearance to Blattella germanica - the German cockroach. The banding on the pronotum is light at the edges and dark in the middle, with some specimens having a light band in the middle. The pronotum of the female of this species can sometimes be much darker than the males with the banding almost totally gone.
S. longipalpa has a very small reddish brown ootheca measuring 4 mm long each one contains 14 - 17 eggs. The temperature effects the development time of the eggs and the nymphal cockroaches. They live on average 115 and 136 days, males and females respectively, at 25C.
