Pest Control for Food Safety

Food Pests

The food pests are the creatures who are destructive, noxious or troublesome and lives on or in the prepared foods or raw materials intended for production of foods or feed for human or animal consumption, which is capable of directly or indirectly contaminate the foods or raw materials. Thus, pest control is an essential part of food safety to prevent the spread of disease, formation of toxic compounds and loss of material including following:

Prevention of contamination through rodents or birds which may result in food poisoning. Rodents are scavengers who use to feed on refuse, waste and or contaminated foods, whereas rats often lives in sewers as well as they are in close association of other animals. Thus, often carry food poisoning bacteria, such as salmonellae, E. coli, etc. both inside and outside their bodies as well as on their feet or mouths. Once they enter to a food processing or holding premise, they can easily transfer the food poisoning organisms to foods or food contact surfaces from their fur, mouths, feet, urine and feces. Thus, rat urine contamination can sometimes lead to Weil’s disease.

Pest control is mandatory, since prevention of wastage due to food contamination as well as losses through the damage of packaging by the pests, which are associated with additional costs due to loss of production, recall of contaminated foods or criminal or civil action as a result of sale of contaminated food stuffs.

It is also important to control pest attacks, because pest damage can cause gnawing electrical fires, burst of plumbing or subsidence, or cause of borrowing may result due to rodent infestations.

Nonetheless, it is important to comply with legislation to avoid possible fines or closure of business as well as to avoid loss of customers who object to pest infested premises as well as sale of contaminated food stuffs. Further, employees will demotivated and abandon the employments due to fear, disease outbreaks or intolerability. 

Common Food Pests

There are various kind of food pests found the industry, however following are the most common in nature.

Rodents – rats and mice

Rodents comprise a group of furred, warm blooded animals which include rats and mice. The two most common rodent encounters are rats and house mice.Rats and mice are attracted by food supplies but do not venture far from their shelter or nesting sites, and 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

There are two types of rats and most common are depend on the region, but brown rat (Norway rat/ground rat) and black rats (roof rat) are usually common in different parts of the world, the brown and black rats are the most predominant varieties who usually borrows in the soil, especially beneath the buildings, or usually found in sewers, drainage lines, farms, and rubbish dump yards. They are usually omnivores in nature, but prefer cereals. Usually one pair of adult rats can produce over hundreds of offspring within a year. But their survival is usually less and need to eliminate them as much as possible since lone invaders become pairs soon which will create major infestations with very short time. The contamination along access routes or foods with urine, droppings, and filth picked up from the environment; damage to food containers and packaging; eating food in storage and on display; transmission 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; rodents are reservoirs for some mosquito-borne diseases.

House Mice

The house mice are normally found inside the buildings which provide harbourage with warmth, food and secured nesting places and material. It is an omnivorous animal where a single pair can produce around 2000 baby mice within a year through horizontal multiplication of their offspring. 

Insects

Insect are the most troublesome group which contains many different groups including flies, wasps, cockroaches, psocids, silverfish, ants, moths, weevils and beetles. Nonetheless, there are another group called stored product insects, who infest serials, flour and biscuits or any made dry foods/raw materials which are under storage conditions. Insects attack food or raw materials which become contaminated with their excreta, webbings, and eggs or their bodies. Furthermore, flies and cockroaches may act as hosts to transmit food poisoning organisms to high risk or made foods. Thus, no food is completely safe from insect attacks, but cereals, beans, flour and dried foods are among the most susceptible to infestation.

Flies

There are many types of flies, which can cause problems in the food industry including the Housefly, the Bushfly, Blowfly and the Fruit Fly. 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, where many pathogens have been isolated from flies, including salmonella, E. coli O157, cholera, shigella, campylobacter, listeria and rotavirus, etc. They also carry parasitic warms and fungi. Thus, flies can contaminate foods or raw materials in four ways; they vomit partly digested pervious meal before feeding starts; and flies continually defecate; they also carry bacteria on their body, legs or hairs; while their pupal cases, eggs, maggots and dead bodies can end up in the foods.

Adult flies lay eggs in moist organic material, for example, food scraps, animal faeces (droppings), grass clippings or dead animals. Theeggs turn into larvae after some hours which are called maggots, who feed on the organic material and grow quickly. After four to five days the maggots move to dry soil and burrow down into it and turn into pupae. A special hard protective covering called a pupal case encloses each of the pupae while they continue to develop. Pupae are brown to black in colour and can sometimes be mistaken for mice droppings.After four or five days, pupae turn into adult flies. They break out of the pupal case, burrow up through the soil to the surface and fly away. Flies are able to travel many kilometres from their breeding place.

Typical breeding sites for houseflies are refuse and decaying organic matter. The female housefly lays around 600 eggs at a time, which hatch within 48 hours and it takes less than two weeks for an egg to pass maggot and pupal stages to become an adult in warm weather conditions. The blowflies usually breed on decaying matter of animal origin, especially meat or fish. Fruit flies generally occur in ripening fruits, bakeries, fruit canning facilities or fruit storages, beer cellars, or may be unwashed milk bottles. The control is carried out with removal of breeding materials.

Wasps

Wasps are usually contaminate foods through transmitting bacteria from their legs or bodies which are a major nuisance in bakeries under warm weather.

Cockroaches

There are different types of cockroaches available in different parts of the world based on different weather conditions.

German cockroach – Blatellagermanica

The adult is about 12-15mm long and colour is yellowish brownor light brown, which is one of the most common cockroaches worldwide and is easily identifiable by two dark stripes on the pronotum (head shield). It prefers warm, humid conditions but can infest food production areas and equipment, food storage areas, kitchens,bakeries, hotels vehicles, offices and administrative areas, bathrooms and especially ship’s galleys. The female can produce around 300 eggs in entire life span of 3 to 12 months. They are good climbers and can climb vertical glass and tiled surfaces, so can spread quickly.

American cockroach – Periplanetaamericana

The largest cockroach that may infest facilities; adults are 35-50mm long and reddish brown. It requires warm, humid environments to survive. They are found in drains, sewers, basements, storage rooms and waste storage areas.

Oriental cockroach – Blattaorientalis

The adult is grows around 20-30mm long, which are shiny dark brown to black in colour. It prefers cooler, dark and damp places to shelter, such as basements and drains, and can be found in storage rooms and waste storage areas. They are poor climbers on smooth surfaces but are cold tolerant (i.e. UK) and can be found outside buildings in drains, sewers, and external brickwork andusually found in cellars, kitchens, bakeries, hotels, etc.The eggs are laid with case which take about two months to hatch at 25ºC, and it will be prolonged in the colder climates. The female produce around 150 eggs in the entire life cycle which usually take between 6 to 12 months to become adults depending on the climatic condition and the food supplies.

Brown banded cockroach – Supellalongipalpa

The adult is only 1015mm long and looks similar to the more common German cockroach. It needs hot humid conditions, around 27°C, to survive and outside warm climates will infest heated buildings and appliances such as light switches and electrical appliances.

Australian cockroach – Periplanetaaustralasiae

A large species similar to the American cockroach. Adults are 25-35mm long with a reddish brown body and paler band around the pronotum (head shield); it is common in tropical climates (probably native to Africa, not Australia) but can survive in colder countries in warm, humid buildings such as greenhouses.

The cockroaches usually live in groups which are omnivorous, nocturnal creatures that gives an unpleasant characteristic odour. They are usually hide during the day time inside cracks, crevices, ducting, false ceilings, behind hot water plumbing, electrical equipment, behind skirtings and broken tiles. They can be detected with the presence of fecal matter, or their smell and they don’t fly. There are over 40 pathogenic organisms have been isolated from their bodies or from the fecal, including food poisoning organisms such as salmonella, clostridium perfringens, Listeria, Staphylococccus, and fungi, viruses as well as 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, storage and display areas on their bodies or in excreta; they defecate along their pathways; they 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 packaging; droppings and shed skins contain allergens, and heavy cockroach populations can trigger asthma attacks.Their presence can be detected through live or dead bodies, nymphs/moths, eggs, larvae and pupae, droppings, egg cases and smell or webbings (moths).

Psocidsor Booklice

Psocids are small insects with 1 to 2mm in size, and colour can be varied from cream, light brown to dark brown, which are omnivorous creatures that infest flour, grain, nuts, chocolate, fish and meat products. They also feed moulds and yeasts where infestation may be associated with packaging materials and pellets. The presence of booklice usually can be detected in high humid areas.