Adult 20-24mm long, dark brown to black, the wings of the male
cover 2/3 of the abdomen, the wings of the female are not fully
developed. They can climb tough surfaces.
ii)German Cockroach (Blattella Germanica)
Adult:- 10-15mm in length, yellowish brown in colour with two
longitudent dark marks on the pronotum, wings are well developed in
both sexes, can readily climb rough and polished vertical
Nymphs:- The nymphs of all species are similar in appearance
to the adult but smaller. Immediately after hatching or moulting
the nymphs are white, but the cuticle soon darkens to the normal
Cockroaches are gregarious and nocturnal, they spend the day
hiding in cracks and crevices around such areas as sinks, drains,
cookers, the back of cookers, backs of cupboards and in
refrigerator motor compartments. Infestations may occur from the
introduction of egg cases or adults in raw materials, crates and
packaging or via drains.
Cockroaches are potential carriers of diseases such as
dysentery, gastro-enteritis, typhoid and poliomyelitis. Their diet
includes fermenting substances, soiled septic dressings, hair,
leather, parchment, wallpaper, faeces and food for human
consumption. Food can become contaminated by the transfer of
causative agents of disease from the cockroaches body or by
transmission of their droppings.
Cockroaches and their faeces may cause allergic reactions
especially amongst those with respiratory disorders. Exposures may
result from ingestion or through inhalation or material derived
from cockroaches in airborne dust.
Food may also be tainted with the characteristic smell of the
cockroach, which is produced by faeces and salivary/abdominal gland
secretions or by the dead insects.
The female lays her eggs in a case (ootheca) which are
extremely resistant to drying up and insecticides. Each of these
cases can contain between 12 and 50 eggs depending on the