COCKROACHES

Cockroaches are common in commercial premises associated with the production or handling of food. Also in public buildings and domestic premises e.g apartment blocks. Gregarious and nocturnal, they spend the day hiding in cracks and crevices around such areas as sinks, drains, cookers, the backs of cupboards and in refrigerator  motor compartments. They especially favour buildings with service ducts and complex plumbing installations You can't however afford to take a chance with cockroaches because they are potential carriers of dysentery, gastroenteritis, typhoid and poliomyelitis. An example where an infestation of cockroaches affected human lives was in a Brussels hospital where an outbreak of food poisoning subsided immediately as an infestation of B germanica was controlled. Their diet is omnivorous and includes fermenting substances, soiled septic dressings, hair, leather, parchment, wallpaper, faeces and food for human consumption.

If left unchecked a cockroach problem can quickly get out of hand. The female German cockroach (B. germanica) produces 4 - 8 egg capsules at approximately 1 month intervals. Each thick-walled resistant capsule is 6 mm long and contains up to 30 eggs, the female then carries the capsule until just before the eggs hatch, some 2.5 - 4 weeks later.

ANTS

The  Common black ant (Lasius niger) is an active insect, that  nests outside in grass and walls and under  paving. It forages widely in search of food, which is how it comes to enter domestic premises. Foraging worker ants cause a nuisance as they travel widely in search of food, following well-defined trails and clustering around the food source. Sweet foods are preferred. In gardens their excavations around plant roots make the soil excessively dry. They will also cultivate greenfly, themselves pests, in order to obtain the sugary honeydew secretions that these aphids produce. On the other hand they can be beneficial as predators of other insects and general scavengers. They are obviously an unpleasant sight and may damage food used for human consumption. The gregarious habits of ants have resulted in the development of a caste system, whereby individuals are responsible for specialised duties within the community. There are: workers (sterile females); fertile males; and queens (fertile   females). The worker ants build and extend the nest, look after larval forms and forage for food, whereby they become pests.

The queens perform none of these duties, but remain almost exclusively within the nest. Mating amongst sexual individuals takes place on the wing. These spectacular swarms involve large numbers of ants. The actual swarms only persist for 2 - 3 hours. After mating the males perish but the females shed their wings and dig a cell in the soil where they overwinter. The eggs are laid in late spring and the white legless larvae hatch 3 - 4  weeks later. The larvae are fed on secretions from the queen’s salivary glands until fully grown, when they will pupate, forming the well-known "ant eggs". From these pupae emerge the first brood of worker ants. These workers take over foraging duties and tend subsequent broods. The sexual forms are not produced until later. The entire cycle takes about 2 months to complete. Under favourable conditions a nest may persist for several years.

FLEAS

Adult fleas live exclusively as parasites of warm-blooded animals, especially mammals, although birds may also be attacked. Whilst they show a certain degree of host preference, fleas are by no means specific and will feed on other animals in the absence of the normal host. In  fact they tend to be more nest than host-specific, for whilst the adults may feed on the blood of a variety of animals the larvae require more precise conditions which are associated with the habitats and nesting habits of the hosts rather than the characteristics of their blood.

Fleas can be carriers of disease or may transmit parasitic worms.

The adult female flea lays four to eight eggs after each blood meal and a single female may produce 800-1000 eggs during her lifetime, which may be as long as two years. The development cycle from egg to adult is normally completed in 4 weeks but at low temperatures will take much longer.