Top pests in hotels and commercial kitchens

Pests are a public health and business risk. They can cause damage to buildings, fittings, furnishings and food products, transmit disease, cause unsightly marks and smells and affect customers in several ways, including illnesses, irritating bites, bad feeling and loss of custom.

Pest infestations impart costs to businesses from:

• treatment to eradicate pests;
• replacement of contaminated stock or defaced items;
• loss of reputation;
• loss of business; and
• potential litigation from the public and regulatory authorities.

Businesses providing products and services to the public are expected to give pest control a high priority. Hotels and restaurants have a responsibility for protecting public health by preventing contamination of food and transmission of pest-borne diseases inside their premises.

Rodents

Rats and mice are attracted by food supplies and do not venture far from their shelter or nesting sites, so in a large facility will nest close to accessible food stores.

Rats and mice are capable of a rapid increase in population given an abundant food supply, due to the number of litters they are capable of producing and the time to maturity, shelter from predators and benign environmental conditions inside a building.

Hazards from rodents

The hazards from rats and mice include:

• damage to buildings and fixtures; the most common problem with the brown rat is damage to electrical equipment, but they can also cause extensive damage to sewer systems by burrowing;
• contamination along access routes with urine, droppings, and filth picked up from the environment;
• damage to food containers and packaging;
• eating the food in stores and packages;
• contamination of food with droppings, urine, filth;
• transmission of a large number of diseases, including Salmonellosis, Leptospirosis, Toxoplasmosis, Lyme disease, rat-bite fever;
• rodents carry ectoparasites, including ticks, fleas, lice and mites and are therefore also vectors for the diseases that these carry.

Signs of rodents

Rats and mice leave distinctive signs that show which pest is present:

• droppings, which have a different size and shape for each species;
• sightings of live or dead animals;
• noises: squeeks, gnawing sounds, scurrying sounds;
• smudge marks along runs caused by their oily fur;
• tracks in dust or powder put down to indicate their presence;
• gnawing of building materials, wiring, food and packaging: the gnaw marks are different;
• urine stains are left along trails by both rats and mice and can be detected using UV light;
• urine pillars form where mice infest an area over a long period — and would show a serious failure in pest control.

Rodent control

Control of rodents involves the elimination of harbourage in and around buildings and preventing access to food, water and shelter. There may be many points of entry to a building, such as cracks, vents, pipes, cabling, drains, doorways, windows, screens, where measures can be taken to prevent access.

Any rodents present must be controlled using traps or poison according to acceptable practices and legislation, including food law, health and safety, environmental and wildlife laws.

Use of rodenticides

Rodenticides used must be registered products, placed in secure bait stations and restricted to areas where food is not handled. If stored on site they must also be stored in suitable conditions that prevent contamination from the poison in food products and the environment.

Expertise is needed to determine the type of bait used, where it should be placed and the frequency, the monitoring regime and the documentation, which is best done using an outside contractor. If done in-house, staff will need to be certified to handle the chemicals and carry out the rodent control activities.

There are specific requirements for documentation in food standards and legislation, such as maintaining maps of all bait stations, records of sightings, records of training of staff, and the monitoring regime, therefore it is important to have trained personnel responsible for this.

As a professional organisation we ensure our front line staff are fully aware of the risks professional products can pose to wildlife and apply this knowledge to reduce any risks to non-target species.

Cockroaches

Cockroaches are the most common type of crawling insect that infests food handling businesses. They cause particular problems because of their size, giving them the ability to hide in small places, their varied diet, rapid reproduction and the diseases they can carry.

Cockroaches are primarily nocturnal, sheltering in the daytime and coming out at night to find food and other sites for shelter. They shelter in dark places such as cracks, crevices, drains, sewers, inside equipment and furnishings and hidden spaces that provide the right temperature and humidity. These places are also hard to reach using normal cleaning and sanitation methods.

Three most common cockroach species:

• German Cockroach (Blatella germanica): the adult is about 12-15mm long and light brown. It prefers wet, humid conditions and is especially associated with infestations of kitchens and food storage areas, but also infests bathrooms, vehicles, offices and administrative areas. It is thought to have originated in East and Southeast Asia and is now the most common cockroach pest in buildings worldwide, maintained by heating systems in cooler climates — it is rarely found outdoors. Its temperature preference is 20–27°C.
• American cockroach (Periplaneta americana): the largest cockroach, with adults 35-40mm long and reddish brown. It requires warm, humid environments to survive. They are found in drains, sewers, basements, storage rooms and waste storage areas. Temperature preference is 24–31°C.
• Gisborne Cockroach: the adult is up to 45mm long and is dark brown to black in colour with distinctive white bands along the sides. It is harmless, unlike German or American cockroaches as it doesn't spread disease, nor can it fly. It typically doesn't invade food supplies, unless they're decaying. It prefers to stay outside under bark or woodchips, however will come inside if it's wet or too hot.

Hazards from cockroaches

• Diseases and allergens: cockroaches can carry a large number of disease-causing bacteria, including Salmonella, Staphylococcus, Listeria, E. coli, and also fungi, viruses and parasitic worms;
• they feed on decaying matter, mould, faecal matter in sewers, from rodents and birds, and animal carcasses, which can then be transmitted into the food production and serving environment on their bodies or from excreta;
• they defecate along their pathways and frequently expel saliva on surfaces to ‘taste’ their environment;
• droppings and bodily secretions stain and leave a foul odour that can permeate infestation areas, food and packaging;
• cast skins and egg cases contaminate products and food packaging;
• droppings and shed skins contain allergens, and heavy cockroach populations can trigger asthma attacks in both guests and staff.

Cockroach prevention

Good sanitation practices prevent infestations and pick up the presence of cockroaches:

• cockroaches can feed on small residues of food left from spills or in food preparation areas, so good cleaning practices which eliminate the residues quickly will deny them a food supply;
• store food in cockroach-proof containers: they eat cardboard so this should not be used for storage;
• maintain drains in good condition to prevent accumulation of food debris and means of access and shelter;
• remove waste from food production areas;
• use a garbage container design that denies access to all pests,
• position garbage containers away from the food storage and processing areas, empty and clean them frequently;
• good building design and maintenance can reduce the risk of cockroach access eg through spaces around pipe and cable ways, vents, screens, windows, doorways, sewers; and harbourage in small spaces such as junction boxes;
• a good inspection regime for equipment, buildings and deliveries will pick up infestations and identify risks quickly.

Cockroach lifecycle

The German cockroach is the most widespread and reproduces more rapidly than the other common cockroaches. After mating, the female produces an egg case containing about 30 eggs and carries it at the tip of its abdomen for about 30 days while the juveniles mature, until 1–2 days before hatching. The juveniles hatch looking like small adults, but without fully developed wings.

The other species deposit the ootheca in a suitable location to incubate for several weeks or months. Young immature cockroaches undergo gradual metamorphosis. They resemble adults and have similar feeding habits, but they do not have fully developed wings and are not reproductively active. Immediately after molting, cockroaches are white, but their outer covering darkens as it hardens, usually within hours.

Cockroach control

A number of treatments are available for control of cockroaches, including sprays, aerosols, dusts and bait. There are stricter regulations for control near food handling and storage areas, to prevent contamination of foods with poisons.

The insecticides used must be permitted for use by the relevant local or national authority and will require competent, trained personnel to apply them.

Rentokil also has chemical-free control methods suitable for sensitive business environments and Insect Monitor Units to detect signs of activity.

Bed bugs

Bed bugs are one of the most troublesome recurring pests for hoteliers. They are impossible to prevent because they are brought in by guests in luggage and clothing. They are also brought in via other means, including employees, external contractors, laundry services, neighbouring properties, second hand or antique furniture and electronic devices.

Once in travellers’ luggage and clothing bed bugs have no problem surviving long journeys. At cool temperatures they can survive several months without feeding so can easily move between hotels across the world or survive in a furniture store.

When in a hotel they can also be carried around in bedding and furniture and crawl from room to room through holes in walls, such as for electrical wiring or pipes. Adjacent rooms on the same floor and on floors above and below can then quickly become infested.

This means it is essential to have an integrated pest management program to minimise the chance of them coming onto your property, monitor their presence to discover their presence as soon as possible and eradicate the pest before it has a chance to spread and breed.

History

Bed bugs have been associated with humans for thousands of years and have been recorded in texts since at least ancient Greece. They belong to the Cimicidae family of small parasitic insects, which consists of around 90 species of small oval-shaped and flat wingless insects that all feed on warm-blooded animals.

Each species tends to prefer particular host animals to feed on, some more specific than others. This is thought to be related to their ability to digest blood of different species and the size of the red blood cells of the host compared to the insect’s food canal.

The common bed bug, Cimex lectularius, prefers to feed on human blood but can also feed on birds, bats, rabbits and mice. It is thought to have evolved from bat bugs, first becoming a parasite of ancient humans when they lived in caves inhabited by bats. One tropical bed bug is also a human parasite: C. hemipterus (also called C. rotundatus).

Several other species that feed on bats, wild birds and poultry, are known to infest human habitation and opportunistically feed on humans, especially when their normal host has left or has been disturbed. The European swallow bug is known to infest houses, crawling from swallow nests in winter time after the birds have left the nests to migrate.

Distribution

The common bed bug occurs across temperate zones, wherever there are people. They are adapted to thrive at the same temperature and humidity levels that are comfortable for their human hosts.

Bed bugs were a widespread problem until DDT was used as an insecticide starting during World War II to control typhus in Europe, and malaria and dengue fever in tropical areas. The near eradication of bed bugs was a side effect of the use of DDT to control these disease vectors. Following bans on DDT around the world and with the increase in international travel, the bed bug has made a strong come back, especially in hotels, care homes, hostels, and dormitories.

Conditions under which the common bed bug thrives include:

• an adequate supply of hosts nearby for blood-meals;
• narrow harbourage spaces within about 1.5m of a host;
• optimal temperature is 22°C;
• relative humidity around 65% or higher.

What do bed bugs look like?

Bed bugs are flattened, brown, wingless insects ranging in size from around 5mm as adults down to 1mm as newly hatched juveniles. The first stage juveniles are pale brown and all stages change colour after a blood meal to purplish red. The feeding also changes their abdomen to be torpedo shaped. The eggs are whitish and less than 1mm long.

Bed bug aggregation

Bed bugs aggregate in colonies at all life stages, attracted to each other by ‘aggregation pheromones’. These were only identified in 2014 by scientists at Simon Fraser University in the US who analysed bed bug faeces after eliminating other possible sources of pheromones. They found that bed bugs are attracted to shelters by a blend of five volatile chemicals in the faeces (out of many that are present), some of which are also common industrial products used as food flavour, pesticide, or paint solvent:

• dimethyl disulphide,
• dimethyl trisulfide,
• (E)-2-hexenal,
• (E)-2-octenal,
• 2-hexanone, and
• Histamine: when bed bugs arrive at a shelter they only stay if histamine is present. This is not very volatile so the bed bugs only detect it when they are close to a source.

The pheromone blend attracts all five juvenile stages as well as adult males and females, both fed and non-fed. These chemicals are thought to be detected at different positions on the antennae.

Reproduction

Bed bugs have a mating method unique to the Cimicidae family of insects, called traumatic insemination. The male stabs the abdomen of the female with its reproductive organ (called a paramere) to release the sperm into a specialised organ inside the right side of the female, the Organ of Berlese. The sperm migrate through the body cavity over several hours to fertilise the eggs.

Females that mate only once produce more eggs than those that are inseminated several times, which is thought to be a consequence of the wounds caused by repeated insemination.

A female bed bug can lay 200 to 500 eggs a month. The females lay eggs anywhere they crawl, either individually or in groups. The number of eggs laid at one time depends on the level of nutrition and the amount of sperm the female is carrying. The female can produce 1–7 eggs per day for about 10 days before having to feed again, but around 5–20 eggs from one blood meal.

Under optimal conditions about 97% of the eggs will survive and hatch. The eggs hatch over 6-10 days, producing the first instar (immature bed bug), which is about 1.5mm long. There are five instar stages, each one needing at least one blood meal before it can grow to the next instar stage. The instar has to moult (shed its skin) to grow at each stage, leaving behind the exoskeleton, which is a characteristic sign of a growing population of bed bugs.

The cycle from egg to adult can take about 37 days in optimal conditions of temperature (22°C) and feeding.

Feeding habits

Bed bugs have to feed on blood every 5-10 days, only leaving their shelter to look for a host when they are starved. They tend to feed at night but if they are starved and cannot find a host at night will search for one at any time, especially if there is one nearby that tends to sleep or sit for long periods during the day. They can obtain additional moisture by absorbing it from the air, so humid conditions help them survive.

Under cool conditions adults can survive for a year without feeding, but under warm climatic conditions they can survive for about five months. Adult bed bugs have an average lifespan of 6–12 months.

Bed bugs are attracted by warmth, carbon dioxide and various body chemicals, which they detect using an array of sensing organs to find a suitable body for feeding on. Scientists have found a wide range of chemicals given off by animals that attract bed bugs. One mixture of spearmint oil, coriander Egyptian oil and some other organic chemicals was found to be the best attractant in a study by scientists at Purdue University. They also found that bed bugs prefer a black to a white surface.

After feeding, the attractant chemicals become repellent, which causes the bed bugs to move away from a danger area.

Bed bugs won’t climb over your body; they crawl along the bedding and feed where your skin comes into contact with the bed, which means the bites will be on the side of your body that you are sleeping on, especially your face, neck and arms.

They need just 5-10 minutes of feeding to become engorged with blood and may spend less than 20 minutes on a host. After feeding or if it they cannot find a host and it is becoming light, they return to their shelter, so spend most of their life there.

Bed bug bites

Bed bug bites are similar to other insect bites such as from mosquitoes and fleas. However, one identifying factor is that they tend to occur in a line on exposed bare skin, especially:

• legs;
• arms;
• face;
• neck;
• hands.

The bites generally come in threes, which are sometimes called ‘breakfast, lunch and dinner’, so a line of three bites can be an identifying factor. If the bugs are disturbed while feeding they will bite multiple times in the same area and they then look like a skin rash.

People’s skin reaction to the bites varies from no reaction at all to red spots on the skin, minor skin swelling and itching. People sleeping in the same bed can have different reactions: one person can have no sign of bites and the other have itchy red spots, but both of them are likely to have been bitten.

The best way to tell that bites are caused by bed bugs and not other insects is to look for the tell-tale signs of the bugs themselves.

Why do bed bug bites itch?

Bites itch because your body reacts to the saliva injected by the bed bug while it is biting you. Bed bugs, similar to other biting insects, have a complex mouth with one needle-like part that pierces the skin and other parts that are serrated and saw through the flesh to find a blood vessel. It also has a food canal to suck up blood and a canal that injects saliva containing anticoagulant and anaesthetic. The anticoagulant keeps the blood liquid so it keeps flowing and the anaesthetic stops you feeling the bite so you don’t disturb the feeding bug.

The body’s immune system recognises the foreign material and produces histamine as a defence mechanism. This causes localised inflammation and itching, but it is also the chemical that bed bugs themselves use to signal safe harbourage.

People have different rates of reaction to the bites depending on the sensitivity of their immune system to the foreign material injected during the bite: the body can take from half an hour to several days to react to a bite. The body also learns to recognise the ingredients in the saliva, so subsequent bites will produce a quicker reaction.

Diseases carried by bed bugs

Bed bugs have been associated with more than 40 human diseases, according to a search of scientific literature carried out for a study by scientists from the University of Mississippi and Mississippi State University. There have been no confirmed cases, however, of any disease being transmitted from a bed bug to a human.

Studies testing whether hepatitis B, HIV, Chagas disease and filariasis could transmit to bed bugs through feeding on infected blood found the organisms did enter the insects, but there is no record of further transmission to humans.

Some studies have shown that bed bugs can be infected with the Chagas disease parasite, Trypanosoma cruzi, by feeding on infected mice. This disease is normally transmitted to humans via the faeces of the bloodsucking triatomine bug, which occurs mainly in Latin America and kills about 50,000 people a year.

A study carried out at the University of Pennsylvania in 2014 found that bed bugs can transmit T. cruzi to other mice both by cohabiting with them and through the faeces transmitting the disease through a skin wound such as a bite or abrasion. Like triatomine bugs, bed bugs defecate as they feed, which is a tell-tale sign of their presence in bedding.

Prevention

Although it is not possible to prevent bed bugs being brought into a hotel, it is possible to prevent them spreading from the initial site by practicing due diligence.

The best strategy is to implement suitable measures to prevent an infestation taking hold:

• good maintenance practices to reduce hiding places;
• use bed bug traps to help detect their presence;
• train your staff how to identify common signs of bed bugs;
• include thorough checking for bed bugs in your room cleaning processes;
• when discovered, inspect adjacent rooms — next door, above and below — to identify if the bed bugs have spread;
• have an effective policy to get rid of bed bugs;
• have a procedure in place for handling bed bug complaints and taking quick action.

It is important to know:

• where to look for evidence of bed bugs; and
• what the signs are of their presence.

Signs of bed bugs

The typical signs of bed bugs are:

• small patches of dark/black stains on a mattress and surrounding areas, which are the bed bug excreta: they defecate as they feed on a sleeping person and as they move around;
• small red or rusty spots of dried blood on bedding: caused by a person inadvertently crushing a bed bug while it is feeding at night and releasing the recently ingested blood;
• live bed bugs: adults are easily visible at 4-5mm long; eggs are 1mm and whitish; juveniles are around 1.5mm and straw coloured on hatching then go through five stages of growth and skin shedding when they grow up to 4mm;
• shed skins of bed bugs: juvenile bed bugs shed skins at each of the five stages of growth, needing a blood meal between each stage; these will be found mainly where the bed bugs congregate or feed;
• sickly sweet smell given off by bed bugs: this is detectable in heavy infestations; trained dogs can also be used to sniff out bed bugs.

Locating bed bugs

Bed bugs range in size from eggs around 1mm long to adults 4–5mm long, which is easily visible to the naked eye. They are most commonly found in bedrooms and sleeping areas because they need easy access to a blood meal at night. They are also found in upholstered chairs and sofas where people sit still for long periods.

In hotels, employees may also introduce them into places where they keep personal belongings.

The nymphs and adults need shelter to hide in, which can be any tiny space near where they can obtain a blood meal. As they locate their meal by sensing heat and carbon dioxide from breathing, they are more likely to shelter near sources of food.

Their bodies are very flat, so even adults can fit in a space as thin as a credit card. The places to look for signs of an infestation are in cracks, crevices, seams and folds, including:

• bed frames and headboard crevices. They can hide in corners and cracks, behind the board on the wall;
• mattress seams;
• carpets and underlay;
• around and inside frames of pictures and paintings;
• behind skirting boards;
• between timber floorboards;
• in cracked or broken plaster;
• behind peeling wallpaper or paint;
• inside electrical sockets and fittings;
• in cupboards and wardrobes;
• in bedside cabinets and drawers;
• on curtains;
• in clothes, toys and other personal belongings.

Only a systematic search of potential harbourages will discover all the locations of an infestation:

Inspect the bed

• sheets and blankets;
• piping along the mattress edge;
• sides, top and bottom of mattress and along stitch lines;
• labels, tags, buttons and other decorations on the mattress;
• bed base edges and along stitch lines;
• inside the frame;
• remove the dust cover from the frame and look under any folds and where the fabric fastens to the frame;
• depressions, countersunk screws and under staples;
• joint, cracks and corners of the frame;
• legs, casters, end caps, joints, welds, holes, seams, cracks;
• skirting board near the bed: top, bottom, cracks, crevices, underneath;

Inspect furniture

• for upholstered furniture, do the same detailed search as the bed, paying special attention to zips; skirting, fabric seams, and folds and crevices under cushions;
• drawers and bedside tables: exterior top, sides, and bottom;
• move furniture away from the wall, inspect the back;
• remove drawers and inspect top, sides and bottom, in cracks and crevices, imperfections, joints, screws and corners.

Bed bug control

Integrated pest management

Bed bugs are difficult to eliminate because of their life cycle and habits, so need an integrated approach to eliminate them economically and with minimal danger to people, property, and the environment.

This involves establishing a system of:

• prevention;
• inspection, identification and quantification;
• implementing control measures;
• monitoring the effectiveness of controls.

Physical elimination

The simplest way to remove visible bed bugs is by using a vacuum cleaner with HEPA filter to contain fine particles that could be allergenic. This will remove a large part of the population but is unlikely to eliminate all of them.

Exclusion

Bed bugs cannot chew through material because they have mouth parts designed to suck blood, so it is easy to seal off any sources of access or harbourage. Sealing holes and cracks, sealing items in plastic bags, or mattresses in encasements will prevent them moving in or out.

How NOT to treat bed bugs

Here is a list of things that people frequently do to try to control bed bugs themselves which are not legal and/or potentially harmful:

• mixing pesticides with other pesticides or ingredients in a way not specified on the label: this can result in dangerous mixtures and is also unlikely to work well;
• using diatomaceous earth that is not a registered pesticide product. Non-approved types may have smaller particles that are hazardous to breathe in. The type used for pesticide application has a different sized diatom, which can reduce breathing hazards;
• using rubbing alcohol: this vapourises quickly, is flammable and has caused many house fires when applied to control bed bugs;
• using unregistered gases to fumigate bed bugs, such as carbon dioxide, propane, helium. They can lead to dangerous low-oxygen situations indoors or cause an explosion. Fumigation requires special products, safety measures and adequate training to apply safely without harming yourself and others.
• using a pesticide in a way that doesn’t follow the label. People have:
  • used a pesticide indoors that is labelled for outdoor use only. This exposes people to dangerous chemicals and can make a home dangerous and uninhabitable;
  • buying pesticides from unreliable sources such as street vendors. The ingredients may be unsafe, unknown or ineffective;
  • applied pesticides to their body. There are no registered pesticides or repellents for use on human skin against bed bugs in the US;
  • used too much pesticide or applied it more often than the label says. Some pesticides take time to work, or the bed bugs may be resistant to that type of pesticide. In that case try one with a different active compound;
  • applied pesticides to beds, furniture, or clothing in a way not specified on the label: The pesticide could poison family members or guests coming into contact with the treated items;
  • used too many fogger products at once, which could lead to a fire and/or explosion.
• use pest strips in a manner not on the label. There have been incidents where people were overexposed and became ill.

Other control methods may be legal, but aren’t necessarily safe, smart or effective. Some of these include:

• Spraying repeatedly, whenever you see a bed bug. This may not violate the safe-use instructions on the label, but it is an inefficient way to apply pesticide, is unlikely to eliminate the infestation and can cause the bugs to become resistant to the pesticide so it will no longer work.
• Do-it-yourself heating treatments such as space heaters and fireplaces: this has resulted in homes burning down; applying heat treatment needs training, safety measures, the right equipment and the right heating regime; too much heat can also damage household goods.
• Do-it-yourself freezing treatments such as freezers, fire extinguishers or opening the home to cold air. These methods may not reduce the temperature enough to kill bed bugs where they are hiding.
• Hiring a company that does not follow integrated pest management (IPM) practices: they may charge less but are far less likely to achieve success or apply treatments safely.
• Hiring a company with no or little experience in controlling bed bugs: they are unlikely to know how to survey a property for bed bugs or to treat a property effectively to eliminate bed bugs in all their hiding places.
• Hiring a company that does not provide a follow-up inspection and repeat treatments if needed: bed bugs are difficult to eliminate; they can be resistant to pesticides, hide in hard-to-access places, reinfest from neighbouring properties or people, or from just one pregnant female.

Flies

A number of fly species are attracted to food odours generated by kitchens: fruit flies, drain flies and filth flies, which includes house flies. Different fly species are attracted to different food products, including fermenting sugars, oils and fats, carbohydrates, and decaying proteins and vegetable matter. For pest control it is important to identify which species is present as each has different attractants and breeding habits.

Fermentation or Vinegar Flies are attracted to fermenting sugary liquids, in which they can feed and breed in very small amounts — in bars, kitchens and restaurants. The liquid can accumulate in:

• garbage containers;
• over-ripe fruit, and some vegetables;
• old drink bottles;
• in drains;
• in spills;
• in cracks in wet floors.

Drain flies are attracted to rotting food, sewage and other organic waste material. They lay eggs in organic waste that can build up in drains or polluted shallow water. They can breed in the gelatinous bacterial films — biofilms — that form on surfaces in drains, septic tanks, compost, and are resistant to cleaning and pest-control chemicals.

House flies breed in decomposing waste such as rotting food and animal faeces.

Blow flies lay eggs in rotting meat, including kitchen and restaurant waste, and dead rats, mice and pigeons.

Risk from flies

In warm conditions and with food supplies flies can multiply rapidly. They feed on faecal matter, garbage, rotting materials as well as stored and processed foods that will be present around commercial kitchens. They will regularly move between the contaminated food sources and clean areas, carrying contaminated filth on their bodies as well as microorganisms internally.

Flies can carry many microorganisms that cause disease in humans, including Salmonella, cholera, Campylobacter spp, E. coli, Cryptosporidium, parasitic worms and fungi.

Flies can pick up contaminated materials on their bodies, feet and mouth parts. Some regurgitate digestive juices and defecate while feeding and resting, contaminating foods and surfaces with microorganisms that can cause disease or decay. Fruit flies are not generally considered to be as great a health risk as other flies. However, they can also carry spoilage microorganisms and diseases.

Controlling flies

The application of standard hygiene practices are particularly important for controlling flies to reduce the attractive odours, feeding material and breeding sites.

These include:

• adequate food hygiene practices in kitchen and restaurant areas;
• food preparation areas, including floors, walls and equipment are cleaned and inspected regularly, including in cracks, crevices and hidden spaces where traces of food and liquid can accumulate;
• supplies are not brought in or stored in a rotting state;
• garbage is disposed of regularly — at least twice a week in hotter climates;
• garbage containers are cleaned and can shut properly;
• drains are kept free of accumulating organic matter and cleaned with appropriate cleaner.

Maintaining barriers to flies, including:

• use of screens on windows and vents in kitchen areas, maintained in good condition;
• doors are kept shut when not in use;
• the building is maintained to prevent gaps appearing in any part of the building fabric that would allow insects to enter;
• UV light traps to catch flies hygienically in food preparation and storage areas.

Elimination

As a last resort pesticide is applied using approved products applied by trained personnel following accepted practice.

Stored product insects

Stored product insects (SPIs), also called pantry pests, include beetles, weevils, moths and mites (which are arachnids) that can infest food in storage. Most dried food products are susceptible to pest infestation, including cereal products, seeds, nuts, dried fruit, spices, powdered milk, tea and preserved meats. All stages of the pest can be present simultaneously in the food: egg, larva, pupa, adult.

SPIs are more likely to infest products that have been opened but can also enter packaging made of paper, cardboard, plastic, cellophane and foil, chewing through the packaging material or crawling through folds and seams. Larvae, especially, can make very small entrance holes that are difficult to detect.

Insects and can contaminate large quantities through physical damage, faeces, cocoons, etc and the introduction of microorganisms that cause further degradation, making food unfit or unacceptable for human consumption or for use in food preparation.

Food can become infested at any point in the supply chain, but is more likely to be infested in stores or when kept on shelves for long periods.

Common pests

The common stored product pests and the foods they infest are:

Moths

• Indian meal moth: nuts, dried fruit and grain.
• Mill moth: flour.
• Tropical warehouse moth: stored cereal, nuts, dried fruit, oil seeds and oil cakes.
• Warehouse moth: cocoa beans, chocolate confectionery, dried fruit and nuts.

Beetles & weevils

There is a very large number of species of beetle and weevil that feed on dried foods such as: cereals/grains, flour, seeds, nuts, pulses, dried fruit, chocolate, spices and processed products including pasta.

Mites

• Cheese mite: cheese, nuts, dried eggs, fruit, flour, tobacco.
• Flour or grain mites: cereals, dried vegetable materials, cheese, corn and dried fruits.

Stored product pest control

Signs of stored product pests include:

• damage to stored products, such as small holes in nuts or grain;
• live or dead insects (small beetles and moths), larvae, pupae or silken webbing on food storage bins;
• infestation, holes, larvae or webbing on the outside of packets or bags;
• larvae, pupae or silken webbing in food harbourages in cracks and crevices around shelves or on machinery;
• larvae, pupae or silken webbing in food spillages;
• larvae, pupae or silken webbing on beams and window sills; and
• pests caught in insects traps.

Following basic practices can minimise the risk of infestation:

• throw away food that is infested with pests;
• buy foods in quantities appropriate for the amount used, so they are not kept in storage for long periods;
• use older products first and use up opened packets first;
• dispose of old products;
• inspect food and packages on delivery: for unbroken packaging, freshness, packaged/use-by date;
• store foods in tight closing containers or in a fridge or freezer where appropriate;
• keep food storage areas clean, including shelves and cupboards, and remove spilled foods such as flour and crumbs; vacuum the area thoroughly, especially in corners, internal edges and cracks; and
• do not use pesticide sprays: they may contaminate food and are unlikely to be effective for pests in packaging.

Fleas

Fleas can be brought into an establishment by guests, pests or pets, including feral cats, when allowed on premises. Fleas are both a nuisance because of their irritating bites affecting customers and staff and a potential health risk by being able to carry a range of bacterial, viral and rickettsial diseases, in addition to protozoan and tapeworm parasites.

Fleas are wingless bloodsucking insects that are about 3-4mm long when adult, reddish brown and flattened sideways, which makes it easier for them to crawl through animal hair or feathers. They have strong hind legs, which gives them the ability to jump on and off a host and move around when they have been brought into a building.

There are several types of flea that can bite humans, pets and animals and are common in the human environment, including:

• cat flea (Ctenocephalides felis);
• dog flea (Ctenocephalides canis);
• bird flea (Ceratophyllus gallinae);
• human flea (Pulex irritans).

Each species tends to prefer a particular animal host, but will still bite to see if the host is suitable before dropping off. Common animals that can bring fleas into contact with humans include cats, dogs, rats, mice, foxes, hedgehogs and birds. Cat and dog fleas will jump from pets, carpets or furnishings to get onto a new host.

Biology

Fleas have four life cycle stages of egg, larva, pupa, and imago (adult). The optimum temperature range for the flea life cycle is 21–30°C and optimum humidity is 70%. When there is a flea infestation in a property, the adults only make up around 5% of the population. It will likely consist of:

• 50% eggs;
• 35% larvae;
• 10% pupae;
• 5% adult.

Following mating the female lays batches of up to 20 eggs in an animal’s fur or feathers after each blood meal. The eggs are around 0.5mm long and white. The eggs hatch into larvae in two days to two weeks. A female can lay up to 5000 eggs over its life time.

The larvae are legless, white, covered in bristles and have mouth parts adapted for chewing. These feed on any available organic matter, such as adult flea faeces, flea eggs, vegetable matter and dead insects. The larvae avoid light, hiding in cracks, crevices and bedding.

With a good food supply the larvae pupate and weave silk cocoons over 1–2 weeks following three larval stages. The larvae mature into adults and emerge from the cocoons in a further 1–2 weeks.

They can, however, overwinter in the larva or pupa stage, and survive as an adult in the cocoon without feeding for several months. The emerged adults have to find a blood meal within about a week to survive. They detect a host from vibrations, heat and carbon dioxide. The average lifespan of an adult is 2–3 months.

Flea bites

Flea bites look similar to mosquito bites, but have following identifying characteristics:

• flea bites have a red spot with a tiny dark spot in the middle, much like other insect bites but with less swelling;
• flea bites occur mainly on feet or lower legs and with two or three bites in the same area;
• flea bites don’t hurt but they can become extremely itchy, lasting several days.

• Do not scratch/itch the bite. This could lead to bigger problems;
• wash the bites with soap and warm water;
• apply an antiseptic spray or lotion to the area to reduce risk of infection;
• apply an icepack to the area to help reduce the swelling;
• take an antihistamine to help stop the itching.

Eliminate fleas

There are several easy measures you can take to get rid of fleas if the infestation is small:

• vacuum carpets, floors, furniture, pet bedding to remove the adults, eggs, larvae and the droppings which are food for the larvae;
• dispose of the contents of the vacuum cleaner carefully to make sure the fleas cannot return;
• groom pets regularly with a flea comb and wash their bedding weekly at 50°C or above;
• washing pets with a shampoo reduces the flea population;
• treat pets with an approved pesticide for fleas;
• apply an approved pesticide in the area of infestation.