Areas around stores, especially waste storage and drains, can provide an attractive array of suitable conditions for flies, if hygienic practices are not adequate.
The Food Retail sector faces threats from pests from multiple sources.
Large stores can stock tens of thousands of products from multiple sources with complex supply chains, requiring efficient monitoring and control procedures for supplies brought onto the premises.
Food handling activities range from raw meat and fish preparation, fresh dairy products, freshly cooked foods and bakery products, fresh fruit and vegetables, in addition to packaged goods.
It is important for businesses of all sizes to maintain sanitation standards and actively prevent pest infestation.
The presence of pests can cause enormous economic loss to the business owner, staff and suppliers.
The potential consequences of failure to maintain standards for the Food Retail sector include:
The major pests affecting the Food Retail sector include rodents, flies, cockroaches, stored product insects, birds, ants.
Rats and mice are attracted by food supplies but do not venture far from their shelter or nesting sites, so will nest close to food sources.
They are capable of a rapid increase in population given an abundant food supply, shelter from predators and benign environmental conditions inside a building.
Rats and mice have distinct but different signatures that show which pest is present:
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 related to food safety.
Technology developed by Rentokil for use in zero tolerance environments such as grocery stores and supermarkets can capture mice and eliminate them humanely without toxic chemicals.
Rodenticides used must be approved products, placed in secure bait stations and restricted to areas where food is not processed. If stored on site they must also be stored in suitable conditions that prevent contamination of 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.
There are specific requirements for documentation in food standards and legislation.
These include maintaining maps of all bait stations, records of sightings, records of training of staff, the monitoring regime, therefore it is important to have trained personnel responsible for compliance.
A number of fly species are attracted to food odours present in grocery stores, including fermentation flies, drain flies and house flies.
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. The liquid can accumulate in:
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, etc, and are resistant to cleaning and pest-control chemicals.
Flies can contaminate fresh foods prepared and on display in grocery stores and supermarkets.
In warm conditions with suitable ‘substrate’ to breed in, flies have a short lifecycle and can multiply rapidly.
Filth flies, including house flies, drain flies and flesh flies are known to be able to carry over 100 pathogens that can cause disease in humans, including Salmonella, cholera, Shigella, Campylobacter, E. coli, Cryptosporidium, parasitic worms and fungi.
Fruit flies are not considered to be as great a health risk as other flies because they are not thought of as filth feeders. However, the females can feed on animal faeces to obtain protein for egg laying, therefore they can transmit both spoilage microorganisms and disease.
The application of standard hygiene practices are particularly important for controlling flies to reduce the attractive odours, feeding material and breeding sites.
Exclusion is dependent on the design and maintenance of the facility, including:
As a last resort pesticide is applied using approved products for use in food premises applied by trained pest controllers following accepted practices.
Cockroaches can cause particular problems in businesses that handle food because of their 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 can shelter in shelving in food stores, dark places such as cracks and crevices in walls and floors, drains, sewers, inside equipment and machinery and hidden spaces that provide the right temperature and humidity.
These places are also hard to reach using normal cleaning and sanitation methods.
Good sanitation practices will help prevent infestations and pick up the presence of cockroaches:
A number of treatments are available for control of cockroaches, including sprays, aerosols, dusts and bait. In food handling premises the insecticides used must be permitted for use by the relevant authority and will require competent, trained personnel to apply them.
Rentokil also has Insect Monitor Units to detect signs of activity.
Stored product insects (SPIs) is a generic term that covers beetles, weevils, moths and mites (which are arachnids) infesting food in storage anywhere in the food chain from the farm to the kitchen.
Stored product pests are most likely to be in a food ingredient on delivery to the retail store or in a processed food product when stored for a long time.
Most dried food products are susceptible to pests.
These include cereal products, seeds, nuts, dried fruit, spices, powdered milk, tea and preserved meats. All stages of the pest can be present simultaneously, eg egg, larva, pupa, adult.
SPIs can also enter packaging made of paper, cardboard, plastic, cellophane and foil.
The entrance holes of some insects are smaller than can be seen by the human eye. For example, the larva of the Indian meal moth, therefore packaging without visible damage may harbour insect pests inside.
Insects and mites may only consume a small quantity of food but 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.
The pest activity in raw product ingredients can also change their physical and chemical properties, causing them to cake during processing.
Beetles & weevils
Buildings provide safe areas for birds to roost around the structure and in spaces such as under roofs. Food stores and waste storage areas may also provide a food supply that attracts the birds.
The most common bird pests are pigeons, house sparrows and mynas.
Birds can cause physical damage by dislodging roof tiles, particularly the larger birds, and blocking guttering with nests and feathers.
They produce substantial amounts of droppings which foul buildings, vehicles, paved areas and building entrances where there are deliveries and staff and the public walk, park vehicles and enter the premises.
Inside buildings, bird droppings, nesting material and feathers can contaminate surfaces, food products on display and in food preparation areas, equipment.
Apart from being unsightly, bird droppings can transmit many human pathogens including viruses, bacteria, fungi and protozoa. More common microorganisms include Salmonella, E.coli and Campylobacter.
Bird nesting and roosting sites also encourage infestations of arthropods such as bird mites, fleas and some beetle species.
Bird control consists of preventing access to food, water and shelter. Basic practices to prevent access to food and water are:
Denying shelter includes eliminating nesting and feeding sites on buildings and in the vicinity of the facility.
This should start with the design of the facility and include measures to prevent access to flat roofs, balconies, ledges, chimney stacks, guttering and culverts, which are favourite areas for nesting.
Ants are more of a nuisance pest than a food safety issue in grocery stores.
They can find their way to food sources in buildings through the smallest gaps. They may infest fresh foods, food preparation areas, shelving, packaged foods — damaging both the packaging and the food inside — and in waste storage areas.
Ants are not vectors of diseases but can pick up disease-causing organisms by mechanical contamination when walking on contaminated substances or surfaces.
There are over 12,000 known species of ant occupying a very diverse range of habitats.
They are generally opportunistic feeders and will forage for any food source available. Some preferring sweet foods and others protein sources or fresh leaves that are used to cultivate a fungus for food in the nest.
Wasted food: food contaminated with ants must be discarded and disposed of;
Reputational damage: the presence of ants in a store and in products bought by customers will cause adverse publicity and potential food safety notices or prosecution;
Economic loss: the cost of wasted foods and their disposal, returned goods, lost business from reputational damage and the cost of food safety orders and prosecution.