Property Management, The Right Way!

Cockroaches

Cockroaches are among the oldest creatures on earth. Fossils not so different from modern cockroaches have been found in 250 million year old rocks. They are also ubiquitous; though originating in hot climates they are now found everywhere. In cooler climates they live predominantly inside warm human habitations. A survey of local authorities in England and Wales in 1993 found that over 80 per cent of authorities had infested premises. More than 60 per cent of hospitals are infested.

Cockroaches are large, robust insects with whip-like antennae and two pairs of wings. The most common species in Britain are German and Oriental cockroaches; Brown-banded and American varieties are also found (the names have little real bearing on the origin of the insects). Adult cockroaches live about 4-14 months, during which time females can produce up to 50 oothecae (egg sacs). Each ootheca contains 12-30 eggs. A female German cockroach would produce about 150 live offspring in an average 8 month lifetime.

Where cockroaches are found?

Cockroaches like:

concealment comfortable temperature food and moisture society Cockroaches like to avoid daylight and hide in cracks and crevices, known as harbourages. They eat almost anything, including cardboard, and come out to forage at dusk and early night. They thrive at temperatures of 20-35 cc., more towards the higher end of the range. They need access to water. They stay together in groups. They are mostly found in kitchens and toilets, e.g. behind cookers or in laundry baskets, at the backs of drawers, behind peeling wallpaper, etc. They move along water pipes and air ducts. Tower blocks are particularly vulnerable to infestation because of the ease with which cockroaches can move through the building. The design of buildings and the materials used in their construction can facilitate the spread of cockroaches. Cockroaches can walk, run, jump and sometimes fly. But probably their main movement from building to building is in transported goods; this can even occur in ships and aircraft.

Cockroaches and disease

There is a possibly apocryphal story of the effects of cockroaches in a clean but overcrowded dwelling where a large number of children occupied a single bedroom. it was observed that none of the children had eyebrows and it was discovered that cockroaches were feeding on the eyebrows while the children slept, there being no other source of food available. Whether or not this story is true, cockroaches are implicated in the transfer of disease. They are bearers of pathogens such as salmonella and staphylococcus. They have been associated with outbreaks of gastro-enteritis, typhus and skin diseases. They taint human food. They are a particular menace in hospitals. Contact with cockroaches can lead to a number of allergic illnesses, including dermatitis, urticaria (another skin disease), rhinitis, bronchitis and asthma. Laboratory workers involved in the breeding of cockroaches for research are particularly prone to these conditions. Some people have an aversion to cockroaches amounting to phobia and can suffer anxiety when in the presence of the insects.

Keeping cockroaches out

Cockroaches are vermin which should be denied access or which should be eradicated if they obtain access. Good hygiene is essential in preventing or limiting infestation. it is vital to deny cockroaches food, water and shelter. Dishes should be washed promptly, food stored in tightly sealed containers, working surfaces kept clean, and all scraps and crumbs cleared up. Rubbish should be kept in containers with tight lids and the bags properly sealed when moved outside. Water spills should be mopped up and all water leaks, sweating pipes, etc. repaired. Remove any clutter where cockroaches might live and mend any holes and cracks in walls. Seal openings around pipes, remove paint and loose wallpaper and replace broken tiles.

Insecticides and other treatments

Eradication of an infestation is a professional job, if complete and permanent removal of cockroaches is to be achieved. Some of the older insecticides can be purchased by members of the public but more modern and effective chemicals are only available for professional use. Insecticides are toxic and present a risk to the user unless properly employed. Once cockroaches have appeared in a block of dwellings, treatment is needed throughout the block to bring about eradication. Both home owners and tenants should report the presence of cockroaches to local authority Environmental Health Departments and demand that eradication is carried out. Eradication begins with trapping and monitoring. Traps are open cardboard boxes placed near harbourages, coated on the inside with adhesives, and containing bait which consists of food mixed with insecticide. For blocks of flats, a representative selection of flats (say 15-20 per cent of the total) needs to be chosen. The number of cockroaches trapped indicates the extent of infestation.

Once this is established, a treatment strategy has to be applied. Wandsworth Council employs five levels of treatment based on the extent of infestation:

four double treatments per year on a quarterly basis, including four trapping programmes associated with double treatment four single treatments per year with trapping each time one double treatment per year with trapping a single annual monitoring visit one-off treatment of individual dwellings. Many different insecticides in many different formulations have been tried to kill or repel cockroaches. One of the oldest, borax, is one of the most effective. Among the older types of insecticides used are organophosphates, carbonates, organochlorine compounds and pyrethroids. However, there are drawbacks to these chemicals:

They are not particularly effective in killing cockroaches while they do kill cockroaches in the immediate area of application, they are not effective in reducing the overall population resistance to pesticides is growing among some strains of cockroach some have a limited effective lifetime, requiring repeated applications they are toxic to humans they have undesirable environmental effects. More recently, attention has focused on the insecticide hydramethylnon (main trade name Maxforce) and the juvenile hormone hydroprene (main trade name Protrol). They are often used in conjunction with the drying agent Drione; the cockroaches die from dehydration. Hydramethylnon can be applied as a gel near harbourages and disrupts the cockroaches' metabolism. Cockroaches are cannibals and this assists the spread of the pesticide. Though slower acting than conventional pesticides, hydramethylnon has a very high kill rate.

Hydroprene acts by preventing cockroaches from reaching sexual maturity and therefore from reproducing. It does not affect adult cockroaches and is usually used with a conventional insecticide. It is reported to be 100 per cent effective. At the moment it is only permitted for use in spraying but research is taking place into other ways of applying it. Other juvenile hormones are also being developed.

Hydramethylnon and hydroprene are not regarded as significantly toxic for humans but caution is advisable. This may be due to their recent introduction and the lack of appropriate research. But they are a definite improvement on previous chemicals.

Taking action

Some councils now try to inform residents of the health effects of cockroaches and the importance of block treatments in eradication and to persuade residents to co-operate with treatment programmes. Residents' and tenants associations have a vital role to play in dealing with cockroach infestation by: educating their members about cockroaches by leaflets, posters, public meetings, etc. persuading their members to agree to access to dwellings for trapping, monitoring, and pesticide application bringing pressure to bear on councils to ensure eradication programmes are implemented ensuring that the pesticide and application method and frequency are not dangerous to people

Complete information about the chemicals, method and precautions should be provided and residents should be able to question council officials before treatment begins.

Councils are able to take action under the Public Health Act 1936 to obtain access to premises and carry out treatments. Council officials must obtain a warrant from a magistrate and can enter at 24 hours’ notice. Conversely, residents have a right to require councils to carry out eradication and this has been sustained in a number of court cases. A tenant obtained over 10,000 compensation from Tower Hamlets Council in 1993 after her flat had been infested for over 10 years. The County Court ruled that the Council's negligence resulted in "severe and persistent nuisance."

The cockroach population increased rapidly in the 1980s but it is now possible that it is being held in check, though no-one really knows. However the combination of public demands for action and the advent of more effective eradication methods do provide an opportunity to bring this major public health hazard under control.

German cockroach (Blattella germanica)

The German cockroach (Blattella germanica) is a small species of cockroach, measuring about 1.3 cm (0.51 in) to 1.6 cm (0.63 in) long; however, they are known to get bigger. It can be tan through brown to almost black, and has two dark parallel streaks running from the head to the base of the wings. Although it has wings, it is unable to sustain flight. The German cockroach is one of the most common and prominent household cockroaches in the world, and can be found throughout many human settlements. These insects are particularly associated with restaurants, food processing facilities, hotels, and nursing homes. In colder climates, they are found only near human habitats, since they are not very tolerant to cold. However German cockroaches have been found as far north as Alert, Nunavut. The German cockroach is originally from Asia, it is very closely related to the Asian cockroach, and to the casual observer they appear nearly identical and may be mistaken for the other. This cockroach can be seen in the day occasionally, especially if there is a large population or if they have been disturbed. However, sightings are most commonly reported in the evening hours as they are most active at night. This type of cockroach can emit an unpleasant odor when excited or frightened.

Pest control

The German cockroach is very successful at establishing an ecological niche in buildings, and is very hardy and resilient against attempts at pest control. This is because of the large number of nymphs produced from each egg case, the short period between birth and sexual maturity, and their ability to easily hide due to their small size. The mother also carries the egg case (called an theca) with her during the germination period, rather than depositing it like other species, a practice which would leave them vulnerable in a human habitat to zealous attempts to wipe them out. This cockroach is also smaller than many other species so it can more easily hide and fit into very small cracks and crevices to evade humans. That is also the main reason they can most effectively be controlled with bait in cracks and crevices near harbourages. These type of pest control methods should kill 95% of the overall population in a property due to their fast reproductive cycles. The German cockroach, discounting the presence of pets, has few natural predators inside a human habitat. The German cockroach's thigmotactic nature compounds the difficulty of pest control treatment. The immature cockroaches will live off excretions and moults from the adult cockroaches and thus can remain hidden away from most surface treatments.

Diet

The German cockroach is omnivorous and a scavenger. They particularly like starch, sugary foods, grease and meats. In certain situations where there is a shortage of foodstuffs, they may eat household items such as soap, glue and toothpaste or they may even turn cannibalistic, often chewing on the wings and legs of each other

Oriental cockroach (aka waterbug and Blatta orientalis)

The oriental cockroach (also known as: waterbug and Blatta orientalis) is a large species of cockroach, measuring about 1 in (2.5 cm) in length at maturity. It is dark brown to black in colour and has a glossy body. The female Oriental cockroach has a somewhat different appearance to the male, appearing to be wingless at casual glance but has two very short and useless wings just below her head. She has a wider body than the male. The male has long wings, which cover a majority of his body and are brown in colour, and has a more narrow body. The odd male is capable of very short flights, ranging about 2 to 3 meters. The female oriental cockroach looks somewhat similar to the Florida woods cockroach, and may be mistaken for it.

Habitat

The oriental cockroach tends to travel somewhat more slowly than other species. They are often called "waterbugs" since they prefer dark, moist places. They can often be found around decaying organic matter, and in sewers, drains, damp basements, porches, and other damp locations. They can be found outside in bushes, under leaf groundcover, under mulch, and around other damp places outdoors.

Adaptation

In order to thrive, cockroaches need a place to hide. They prefer warm places and a relatively high humidity if possible; they also need a source of food/liquid. The optimum temperature for oriental cockroaches is between 20 °C (68 °F) to 29 °C (84 °F). Female oriental cockroaches have vestigial tegmina (reduced forewings) and males have longer tegmina. Cockroaches are mainly nocturnal. Oriental cockroaches can be elusive in that a casual inspection of an infested dwelling during the day may show no signs of roach activity.

Distinction

Signs of cockroaches are their oothecae, which are “egg cases” containing up to 16 individual eggs in the case of oriental cockroaches. These oothecae are dropped by females and hatch on their own in about two months. Oriental cockroaches can be harder to get rid of than other roaches. Although adults can be fairly easily killed by the application of residual insecticide, the insecticides can get washed away, and two months later females can hatch new nymphs.

Cockroaches are among the oldest creatures on earth. Fossils not so different from modern cockroaches have been found in 250 million year old rocks. They are also ubiquitous; though originating in hot climates they are now found everywhere. In cooler climates they live predominantly inside warm human habitations. A survey of local authorities in England and Wales in 1993 found that over 80 per cent of authorities had infested premises. More than 60 per cent of hospitals are infested. Cockroaches are large, robust insects with whip-like antennae and two pairs of wings. The most common species in Britain are German and Oriental cockroaches; Brown-banded and American varieties are also found (the names have little real bearing on the origin of the insects). Adult cockroaches live about 4-14 months, during which time females can produce up to 50 oothecae (egg sacs). Each ootheca contains 12-30 eggs. A female German cockroach would produce about 150 live offspring in an average 8 month lifetime.

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