Cockroaches

Did you know cockroaches can live a month without food, but will survive only a week without water?

COCKROACHES

Why cockroaches are considered pests?

While there are 3500 species of cockroach worldwide, only about 10 species have seriously exploited the dwellings of humans. Cockroaches are among the most common pests in many homes and other buildings. At night they search for food in kitchens, food storage places, rubbish bins, drains and sewers. That’s why occupants of infested premises are often unaware of the extent of cockroach activity which commences after dark. They are pests because of their filthy habits and bad smell. Some people may become allergic to cockroaches after frequent exposure. Cockroaches can sometimes play a role as carriers of intestinal diseases, such as diarrhoea, dysentery, typhoid fever and cholera.

Pest cockroaches live in close association with people. They are tropical in origin but in the temperate zones most species live in parts of houses and other buildings where warmth, moisture and food are adequate. Cockroaches usually live in groups. They are mostly active at night; in the daytime they hide in cracks and crevices in walls, door frames and furniture, and in secure places in bathrooms, cupboards, steam tunnels, animal houses, basements, televisions, radios, and other electric devices, drains and sewer systems. If the lights are turned on in an infested kitchen at night the cockroaches will run from dishes, utensils, working surfaces and the floor towards shelter.

Cockroaches eat a great variety of food, including all food used for human consumption. They prefer starchy and sugary materials. They sip milk and nibble at cheese, meats, pastry, grain products, sugar and sweet chocolate. They also feed on cardboard, book bindings, ceiling boards containing starch, the sized inner lining of shoe soles, their own cast-off skins, dead and crippled cockroaches, fresh and dried blood, excrement, sputum, and the fingernails and toenails of babies and sleeping or sick persons.

Typically, infestations of pest cockroaches develop in and around buildings and other structures that provide food, shelter, and often the preferred conditions of temperature and humidity. A commercial kitchen may support hundreds or even thousands of cockroaches at varying stages of development. They may be carried from place to place as live individuals or as egg cases, in food packaging, luggage, furniture, buses, trains, ships and aeroplanes.

• Loathsome Appearance, Rapid and Unpredictable movement, Large Number

Many people are annoyed or scared by the sight of cockroaches. This may be related to their fast unpredictable movements and perhaps very spiky legs.

Cockroaches are social insects that usually live in groups. Cockroaches emit pheromones that leave chemical odours in their faeces and on their bodies. These pheromones serve as means of communication for the insects. The odour of the pheromone causes the roaches to cluster together in a harbourage area to increase breeding opportunity. 

• Odour, Contamination, Potential Disease Carriers

Where a substantial cockroach infestation exists, an unpleasant odour may develop, owing to secretions from mouth and cuticle.

Cockroaches move freely from building to building or from drains, gardens, sewers and latrines to human habitations. Because they feed on human faeces as well as human food they can spread germs that cause disease. They contaminate food products, utensils and various areas with droppings, cast skins, empty egg cases, dead cockroaches and vomit marks on surface. 

Cockroaches are not usually the most important cause of a disease, but like houseflies they may play a supplementary role in the spread of some diseases. They are proven or suspected carriers of the organisms causing: — diarrhoea — dysentery — cholera — leprosy — plague — typhoid fever — viral diseases such as poliomyelitis. In addition they carry the eggs of parasitic worms and may cause allergic reactions, including dermatitis, itching, swelling of the eyelids and more serious respiratory conditions.

• Transfer of Pathogens, Allergies

Cockroaches can carry pathogens that may cause disease. According to the World Health Organization, cockroaches are known or suspected carriers of the microorganisms that can cause diarrhoea, dysentery, cholera, leprosy, plague, typhoid fever and viral diseases, such as poliomyelitis.

One study at Cambridge University identified 30 different species of bacteria associated with cockroaches living in close proximity to humans (across 50 different apartments). Although cockroaches haven’t been linked to any specific outbreaks, they may play a role in spreading certain infections. Though they likely won’t be the main cause of a disease spreading, they can play a supplementary role. 

Some people are allergic to cockroaches. Extracts of cockroaches can bring about positive skin reactions in sensitive people, and may cause an asthma attack in asthmatics. The allergen may be ingested where foods are contaminated with faeces, or inhaled when dried faeces become a part of house dust. Current research shows that asthma and other allergies can be worsened by the presence of cockroaches. Asthma is one of the most prevalent causes of hospitalization in children. According to the Mallis Handbook of Pest Control by Arnold Mallis, “About 26 percent of the U.S. population is sensitive to German cockroach allergen by skin-test.”

Cockroaches produce a protein that can prompt an allergic reaction in many people. Their saliva, waste, cast-off skins and even the dead members of their colonies can all serve as triggers.

Major Cockroach species which bug you in Australia

• American Cockroach 

This is probably the largest cockroach species (35-40 mm long) which infests buildings and utilities. Adults are reddish brown or mahogany coloured. The area behind their heads (pronotum) is outlined with a pale yellow band. The adults are fully winged and apt to fly in warm weather. They can survive 2-3 months without food if they only have access to a water source. Female American cockroaches make protective cases (ootheca) for their eggs. These cases are capsule-shaped. After forming a capsule, the roach deposits or glues it to surfaces within reasonable proximity to food and water in a warm, humid area (Egg cases glued to food packages or boxes, pallets and the like, play an important role in its dispersal). Up to 16 eggs may hatch from each egg case. Females may produce up to 50 egg cases in their life span which is 6-12 months. 

American cockroaches normally live outdoors. As they prefer warm, moist and dark conditions, they can be extensively found in wall, roof and subfloor voids and in and around sewers, drains, moist cellars, grease traps and rubbish dumps. Although, in colder regions they tend to live indoors. Infested buildings include hospitals, bakeries, food stores, warehouses, factories and domestic residences. American cockroaches enter homes to find water or food. They can easily pass under doors if the weather stripping is damaged.  Basement windows and garages are also common entryways. When American cockroaches enter homes, they often go to bathrooms, kitchens, laundry rooms, basements and subfloors.

American cockroaches leave their tiny black droppings (similar to ground coffee) in the dark areas where they hide. You may find these droppings in cupboards, in pantries or behind appliances.

• Australian Cockroach

Australian cockroaches are relatively large (30-35 mm long). In appearance, adults are similar to American, but the body is darker brown and the forewings have a distinct yellow marking. Egg cases that are dropped or glued to surfaces by females may contain up to 24 eggs. Adults live about 4-8 months, during which time females may produce up to 20 egg cases.

Their preferring food of plant origin, attract them to greenhouses and feeding under bark, leaf litter and decaying vegetation in gardens. As well, they are found in subfloor voids, wall voids, roof voids, around utilities in buildings, and in and around woodpiles.  

• Brown Banded Cockroach

This cockroach is relatively small 11 to 14.5 mm in length. Adults are light brown with very pale bands across the body. Both males and females are winged. Egg cases contain up to 18 eggs. Adults typically live for up to six months, during which time the female produces up to 13 egg cases.

This cockroach tends to be an indoors pest, frequently infesting the dwelling parts of the buildings, as well as offices, hospitals, restaurants, storerooms and so on. Unlike the German cockroach, however, its activity may be scattered throughout a building rather than being restricted to kitchen area.  It prefers dry and warm locations and can be found inside cabinets, pantries, closets and near the ceilings of the infested homes. They can also be found in electronic equipment or around refrigerator motor housings.

The brown-banded cockroach is very active and may fly if disturbed or in warm condition. Its wide dispersal within premises cam make control difficult.

• German Cockroach

This relatively small (12-15 mm long) cockroach is probably the most widespread and successful one which coexists with humans in buildings. Its small size facilitates establishment in small cracks and crevices, and its prolific breeding capacity allows it to build up large population in a relatively short period of time. So, it is the hardest pest cockroach to get rid of and is the most troublesome in Sydney. It is the most prolific breeder of all pest cockroaches, taking as little as 40 days to develop from hatching to adulthood. Adults are light brown with two dark longitudinal stripes on the pronotum.  Egg cases are carried by the female until just prior to hatching, and these may contain 30-40 eggs. They eat almost any organic material found in food, ranging from crumbs to built-up grease. Wherever water is available, adults may survive a month or more without food. 

This cockroach seeks conditions that provide warmth, moisture and food. The majority of infestation occurs in kitchens or other food-handling areas, both domestic and commercial within which they hide in cracks and crevices during day time. In kitchens, they are usually found in pantries, storerooms, under sinks and cupboards, in and around drawers, in and around water heaters and appliances such as refrigerators, stoves, microwaves, and in wall voids adjoining kitchens and bathrooms. Their presence in commercial areas such as food-handling factories, storerooms, restaurants, cafes, food bars, canteens, hospitals, hotels, clubs, and schools is typically unavoidable. 

German cockroaches in your house may have already been there when you moved in. They are also easily transported from infested dwellings to new places, so they may have moved with you from your previous home in food packages and cardboard boxes. They may come from your neighbour’s property. In multiunit apartments, they easily move between units, using the shared plumbing and pipes as a highway.  

• Oriental Cockroach

The oriental cockroach (20-25 mm long) is shiny dark brown to black. Adult lifespan is usually about 3-6 months. The female may produce up to 14 egg cases each of which may contain up to 16 eggs during her adult life.

The oriental cockroach prefers cooler temperatures and feeding on a variety of decaying organic matter, trash and starchy origins. So, it may be commonly found outdoors under leaf litter and bark, in garbage disposal area, in damp subfloors, cellars and around drainage systems. It is relatively sluggish and can’t fly or climb so it is usually located at or below ground levels of the buildings.  

• Smoky Brown Cockroach

This relatively large cockroach (30-35 mm long) is entirely brownish-black colour with no pale markings. There are fully developed wings in both sexes which makes them excellent fliers to fly short distances in warm conditions, often being attracted to lights at nights. Its life history is somewhat similar to that of American cockroach. Adult lifespan is about 6-12 months, and during this time, a female may produce close to 20 egg capsules which may contains up to 26 eggs each. 

Smoky brown cockroach is often regarded as an outdoor species which prefers feeding on plant materials, so it is often a pest in greenhouses, nurseries and gardens. They are commonly found in garages, sheds, subfloors, roof voids, in and around gutters, landscaping beds and ivy or other ground covers. They become a pest when, attracted by interior lights, they gain entry into a home or structure through openings in windows, doors, and other gaps into the home. 

Housekeeping Preventative Measures & Control Tips

Where very poor sanitation and hygiene practises exist, chemical treatments will be limited in their effectiveness.  

As cockroaches living in and around buildings require food, water and shelter, reducing the availability of resources is likely to lead to reductions in population size. The practice of hygiene and sanitation in and around dwellings will make buildings less suited to cockroach infestation. 

• Clean-up after food handling should be immediate, thorough and regularly carried out.
• Dishes and utensils should not be left unwashed overnight.
• Cereals, flours, meats and all other food materials should be kept in a refrigerator or stored in tight cockroach-proof containers in pantries or storerooms. 
• The trash in the kitchen, bathroom, and bedrooms should be stored in tightly closed garbage bins. And don’t forget to empty bins daily.
• Regular clean-up of long term build-up of waste foods (e.g. grease accumulation around stoves and vents, or split food materials at backs of shelves) should be carried out.
• Vacuuming of shelves in cupboards and pantries will reduce the build-up of food particles in cracks and crevices. 
• Floorboards should be regularly swept and moped to remove any accidentally spilt food, oil, or dropped crumbs.
• The carpet area, under furniture and the edges of skirting boards, should be regularly vacuumed to avoid the accumulation of crumbs and other food particles.
• The toaster should be periodically cleaned by cleaning the interior, removing and cleaning the crumb tray to get rid of the built-up crumbs. 
• Pets’ feeding bowls should be removed and washed at night time.
• The food-contaminated surfaces such as kitchen benches, work surfaces, kitchen floor, kitchen sinks, on and around stove should be cleaned immediately after daily activities are finished.
• Water availability should be reduced where possible. Unnecessary containers with water such as pets’ water bowl should be removed overnight. Leaky taps, showers or pipes should all be repaired.
• Get rid of empty cardboard boxes in your home or garage. 
• Cut the shrubs and ivy off the wall of your home to remove conducive conditions for cockroach harbourage. 
• Avoid having plants or bushes directly against any external walls.
• Keep firewood piles away from your home.
• Check potted plants, cardboard boxes and second hand furniture or appliances thoroughly before bringing them home.

Housekeeper’s Pre-treatment Cooperation

• Open all curtains and close the windows.
• Wipe down counters, sweep floors, and clean up spills to reduce potential cockroach food sources and make baits more effective.
• Vacuum thoroughly to eliminate crumbs, even tiny crumbs you can’t see.
• Store food in pest-proof containers, or place it in the refrigerator.
• Cover or put all exposed food away.
• Cover food preparation surfaces or wipe them with a piece of wet soapy cloth after treatment.
• Remove or cover children’s toys.
• Cover baby’s crib or cot.
• Remove or cover pet’s feeding bowl, water bowl and sleeping bed.
• Cover fish bowls or tanks with a waterproof cover or a towel.
• Move furniture and appliances 10-15 cm away from the walls and treatment areas.
• Make sure your crawl spaces (roof void, subfloor) are easily accessible for treatment. 
• Severe asthmatic people, infants, young kids and pregnant ladies must be vacated for 3 hours while treatment is carried out. 
• Take your pets out for a couple of hours while treatment is carried out.
• Every body’s recommended to vacate home, leaving ventilation on and get back home after a couple of hours when the chemical is dry.

 After Treatment Care & Control Tips

• Be patient. Because baits do not immediately kill the German cockroaches, it can take normally 3 weeks for the results to be obvious. Rest assured that baiting is the best way to eliminate all of them. 
• While the baits are taking effect, do not spray any insecticides or kill German cockroaches that you see, as they need to continue to feed on the baits to take the poison back to other roaches.
• Avoid using strong cleaners near the bait. This would eliminate the German cockroach’s pheromone trail that other roaches are using to find the bait.
• Avoid mopping the edges of your floors for a while after treatment if you want the full strength of pesticide on the control of pests. You can mop the middle of the floors and leave the edges for the loathsome critters. 
• Wipe down counters, sweep floors, and clean up spills to reduce potential ant food sources and make baits more effective.
• Store food in pest-proof containers, or place it in the refrigerator, as applicable.
• Vacuum and sweep regularly.
• Keep the rubbish in a sealed bin and empty it regularly.
• Wash dishes or run the dishwasher regularly.
• Never leave pet food sitting out after the pet has finished eating. 
• Rinse recyclables thoroughly, if you collect them in the house before taking them out. Store them in a pest-proof container until they are taken away to a recycling center.