Distribution

Cockroaches are commonly found in commercial facilities where food is produced or processed. They are also found in public buildings and residential structures such as apartment buildings. Cockroaches, which live in swarms and emerge at night, hide in cracks and places such as sinks, sewage pipes, behind ovens and cabinets, and refrigerator motor compartments. They especially like buildings with service ducts and complex plumbing. Infestations can occur when eggs or adults enter the building on incoming laundry or raw materials, in crates or packaging, or through sewage pipes or garbage chutes.

B. orientalis and B. germanica are the most common species in Northern Europe. These species are rarely seen together. B. germanica generally prefers warmer and more humid environments such as centrally heated buildings, while B. orientalis prefers cooler and less humid places such as basements and sewage pipes. P. Americana and P. Australasiae species are species that live in tropical and subtropical climates, but they are also seen in ports and loading areas in temperate climates.

Why Should They Be Controlled?

Cockroaches are potential carriers of diseases such as dysentery, asthma and typhus. Cockroaches are both carnivores and herbivores, and their preferred foods include yeast substances, dirt, septic substances, hair, skin, parchment, wallpaper, feces and human food. Human food can be contaminated by mechanical transfer of disease agents from the insect's body or spread in feces. The source of a food poisoning outbreak in a hospital in Brussels was found to be B. germanica and was quickly brought under control.

Cockroach feces can cause allergic reactions in sensitive individuals or asthma patients. Transmission can occur through ingestion or inhalation of materials taken from cockroaches in various ways. In addition, the characteristic odor of cockroaches caused by feces and saliva/gastric gland secretions or dead cockroaches can permeate food.

Control Methods

Successful control of cockroaches is a complex issue and depends on the selection and implementation of the measures to be taken according to the relevant species.

Assessment of Infestation

An assessment should be made to determine the species and extent of the infestation causing the infestation. Plans of the relevant area are required for this. The entire area should be inspected, including adjacent structures, normally inaccessible areas, and sewage pipes. Since maximum pest activity is seen at night, it would be better if the inspection is done at night.

This examination can be done using cockroach monitoring traps that reveal their droppings, shed skins, and egg cases. A pyrethroid-based aerosol (except for Oriental cockroaches) sprayed around and on potential hiding places will drive the cockroaches out.

a) Hygiene/management

Maintaining a high standard of hygiene is important in the control of cockroaches and includes the following:

• Preventing access to food and water sources. This practice will increase cockroach activity and the chance of directed movements encountering insecticides.
• Preventing access to shelters in buildings and equipment that provide cockroaches with hiding places and access to dispersal and breeding grounds.
• Ease of cleaning. Buildings and equipment should be designed to minimize sediment build-up and provide ease of cleaning.
• Inspection of incoming materials including packaging and laundry
• Environmental controls such as ventilation that will accelerate dehydration of pests and interfere with the activity of antenna chemo receptors

b) Control with Insecticides

Surface Sprays

Effective application depends on the selection of a suitable insecticide and its comprehensive application. Many pests and their eggs are well hidden; therefore, the insecticide should be placed in and around these shelters and maintained throughout the developmental period of the species concerned. Insecticide for the control of an infestation should ideally continue to be effective until all eggs are broken, but continued migrations may necessitate routine application.

Area Sprays

Regular applications, such as weekly, are required until the infestation is under control. Thereafter, maintenance applications at more frequent intervals will keep the pest population at an acceptable level. Initially, a large number of adults and nymphs will die, and as a result, occasional young nymphs will be seen.

Insecticide Baits

Baits allow for the controlled placement of insecticides formulated using attractive foods. Cockroaches feeding on the bait will receive lethal doses of the insecticide when placed in areas where cockroach infestation is seen. Baits allow for continuous control of cockroaches over a long period of time. These baits can be combined with surface or area spray applications.