Cockroaches

Generally two pairs of wings, although these maybe reduced or even absent; forewings have well developed veins and tend to be hardened, they overlap down the mid-dorsal line; membranous hindwings are folded below forewings; long whip like, many segmented antennae; omnivorous, with mouth parts adapted for biting; tarsi, 5-segmented; incomplete metamorphosis, with egg and nymph stages.

Special Characteristics

American cockroach- Adult, 28-44mm long; colour, red-brown with yellow border around pronotum; no yellow submarginal stripes on forewings; last segment of cerci, twice as long as wide.

German cockroach- Adult, 10-15mm long; yellow-brownish with two longitudinal dark marks on pronotum; wings well developed in both sexes, can readily climb rough and polished vertical surfaces.

Oriental cockroach-Adults, 20-24mm long; colour, dark-brown, nearly black; wings of male cover two-thirds of abdomen, wings of female are vestigial; can climb rough but smooth vertical surfaces.

Nymphs- The nymphs of all species are similar in appearance to the adult but smaller. Immediately after hatching or molting the nymphs are white, but the outside soon darkens to the normal colour.

Cockroaches are common in commercial premises associated with the production or handling of food. Also in public buildings and domestic premises eg. apartment blocks. Gregarious and nocturnal, they spend the day hiding in cracks and crevices around such areas such as sinks, drains, cookers, the backs of cupboards and in refrigerator compartments. Cockroaches can live more than a month without food, but only a week without water. A cockroach can live without its head but then dies due to lack of water.