2nd Sem - Unit 05 - Pest Control

PEST CONTROL

Pests: Under ordinary conditions of nature, any creature, it may be animal, insect or plant, can only exist in such numbers as can succeed in evading natural enemies, in finding adequate food supply and in securing shelter and suitable conditions for breeding. If these conditions are disturbed, there is an immediate response in the survival rate-up or down. As the case may be, and in general it is only when the favorable factors-sometimes quite obscure and therefore, difficult to counter act-become excessive that the creature develops into a pest.

These considerations lead to an obvious deduction that if favorable factors can be traced and either removed or counterbalanced with unfavorable conditions introduced by human agency, a fair amount of control over the pest would soon be obtained, and this is exactly what is aimed in scientific pest destruction.

A Pest is an organism that competes with human, animals for food and water, damages structure, transmit diseases to humans’ wildlife and annoys humans.

Types of Pests

        · INSECTS-COCKROACH, TERMITE, BEETLE, FLEAS

        · ANTHROPODS-SPIDER, ANTS. TICKS

        · RODENTS-RAT, MICE

        · MICROBIAL ORGANISMS – BACTERIA

NOTE – A Species may be a pest in some situations and not in others.

Categories of Pests

        · CONTINUOUS-Always present and require regular control

        · CYCLICAL/ Sporadic  – Which require control occasionally

        · POTENTIAL-Do not requires control under normal conditions but may require control in certain circumstances.  

Importance of Pest Control

Pest control is made up of all the methods and practices of keeping pests away. Its application goes beyond what we usually know of it in homes. It is used in agriculture and in other vital industries.

Points

       · Contamination of food leading to food poisoning and other serious diseases in humans

       · Legal requirement - according to the prevention of Food Adulteration Act (1954) serving insect infested food is punishable by law.

       · Wastage and destruction caused by the rodents   and insects.

       · Reputation of any catering establishment depends largely on the prevailing hygienic conditions.

       · Pest control measures would go a long way in building up good will among customers and in turn will improve financial gains, provisions of a pest free pleasant atmosphere to customers and employees of the hotel.

      · Protection of sensitive equipments like computers, lifts, machinery etc; from malfunction due to gnawing of wires by rats

      · Protection of most expensive assets like carpets and wooden furniture from pests like moth, carpet beetles and wood borers

Classification

·         Wingless

1.       Fleas

2.       Lice

3.       Bedbugs

4.       Silverfish

·         Winged Mosquito

1.      Houseflies

2.      Cockroaches

These insects are frequently though not necessarily associated with dirt. They abound in unhygienic conditions and their entry into clean places may be entirely accidental.

Fleas

·         There are many different kinds of fleas and each has a preference for the kind of host, e.g. human, cat, dog, vermin, etc. Any of these hosts may introduce fleas into an establishment. Fleas bite their host causing annoyance; and in case of humans, large red itching spot appears on the skin. Flea born epidemics are plague, endemic, murine, and typhus.

·         These are wingless insects 2-3 mm long with laterally flattened, hard thoraxes and abdomen, and three pairs of legs. They are bright coloured and both male and female suck blood.

Life history

·         8-12 eggs at a time – within 2-4 days (summer) and ½ week (winter) the eggs hatch and hairy larvae appears – develops into pupa in 2 weeks time by spinning a cocoon covered with dirt and dust, in which it pupates – in 2 weeks time develops into an adult flea.

Habits

·         They prefer darkness and are sensitive to light. In the absence of rats, when starved they bite men. They travel about 20-30 yards, and can jump up to 3 inches.

·         Spraying with insecticide is a suitable way of eradicating them.

Lice

·         They are small wingless ectoparasites with hard chitinous covering and having three pairs of legs, each provided with a single claw. They live entirely on mammalian blood. They have oval grayish bodies that become brownish when filled with blood.

·         Head lice, which live in the hair of the head, are probably the most common of all lice. They cause intense irritation and such blood. Their eggs called ‘nits’ are numerous and stick firmly on hair, and cannot be removed by brushing.

Diseases conveyed

·         There is no disease that can be directly attributed to lice, but they cause irritation and annoyance and loss of sleep.

Life history

·         A female lice within 48 hrs of assuming adult form, produces it’s eggs. It lays about 300 eggs during it’s lifetime. In seams of clothing the eggs may remain alive for 30 days. The male is about 3mm long and female 3.3mm. The larva emerges in 6-7 days, during which 3 molts occur and insects become adults. A lice takes 15 days period to complete its cycle from an egg to it’s development of adult stage.

Average life span of lice

·         36 to 58 days.

·         Anti-lice measures include general cleanliness of body, hair, clothes and articles of the room.

Bedbugs

·         No insect is more difficult to eradicate from a building than a bed bug. The main difficulty is to get at it. Gammaxine, D.D.T or kerosene oil containing pyrethrum maybe sprayed for exterminating the bed bugs. Cyanic acid, if used for the purpose, gives very good results, but it’s use requires a great care on account of having poisonous effect on human beings. It must also be emphasized that if articles are removed from the room, they should be thoroughly inspected first.

·         A bed bug measures from 3-5 mm in length and 1.5 to 2.5 mm in width. It is dark brown, thin, compressed creatures, so it takes it’s way in narrow cracks. Both male and female bugs bite, which cause considerable irritation and may result in large red patches with swelling.

·         They prefer human blood and are able to survive sometimes many months without food. They are natural by habit and deposit their eggs in crevices and cracks of woodwork and behind wallpaper. The eggs are stuck ton these surfaces by cement like substance exuded by the bug and are therefore difficult to brush off.

·         Bedbugs cover considerable distances although they cannot fly. They also give off an unpleasant smell.

Life history

·         Females lay 1-12 eggs at a time several times a year – hatch in 7-10 days – larvae molts soon after a blood meal – reaches the adult stage after 4 subsequent molts – in another 2 weeks becomes sexually mature. Lifecycle takes about 8-10 weeks to complete.

Silver fish

·         They are wingless insects, silver gray in colour and about 1 cm long. The young closely resemble the adults and both are rounded in front and tapered towards the rear. Silver fish require a moist place in which to live. They leave their hiding places in search of food of cellulose nature. They feed on starchy food, paste in wallpaper and books, and may attack clothing made of cotton or rayon, especially if starched.

·         Gamaxine, D.D.T, pyrethrum maybe sprayed for exterminating silver fish.

Cockroaches

·         They are more likely to be found in the kitchen and restaurant than in accommodation areas, although cockroaches do not necessarily require human food; and will feed on whitewash, hair and books if no other food is available.

·         Hygienic storage and disposal of food and waste and the cleanliness of all areas where food is handled are important points in the prevention of infestation.

·         Cockroaches are difficult to eradicate but a residual insecticide, for e.g. chlardecome, may be used in cracks, crevices and holes; especially in brick or plasterwork through which warm pipes pass.

Mosquitoes

·         They are often referred to as ‘biting flies’ but they are in fact, piercing insects, for the jaws of the female are transferred into a needle like object with which to penetrate the skin, when a blood meal is required. The initial stages of their life viz. egg, larval and pupae stages are spent in water. The presence of water is therefore extremely necessary for their existence. The male mosquito lives rarely 1-3 weeks. The female may live up to 4 mths or more. Mosquitoes prefer dark to light colours. Provision of the blood meal is essential for the female mosquito before laying a batch of eggs.

Life cycle

·         The female lays100-250/500 eggs on the surface of water. In 2-3 days, the eggs hatch out and a small worm like larvae appears. These larvae feed on vegetables. The larvae cast its full size in 6-10 days, when it changes into a coma shaped creature called Pupa. In 2-3 days it splits up and an adult mosquito emerges.

Methods of prevention and control

·         To do away with the conditions which render possible the breeding of mosquitoes.

·         To destroy the mosquito at some period of life.

·         To prevent the mosquitoes from biting man.

A. To do away with conditions which render possible the breeding of mosquitoes -

·         Proper drainage

·         Proper water disposal

·         No stagnant water

B. To destroy the mosquitoes at some period of life –

·         Kerosene oil / diesel is sprayed on the surface of water once a week

·         Pyrethrum extract: Pyrethrum extract 2%

·         Pine oil

·         Kerosene

·         All the above are mixed in liquid soft soap and a concentrated stock solution is made. This is diluted 10 times with water and stirred thoroughly before spraying.

·         Paris-green-aceto-arsenite copper is mixed with100 parts of fine road dust, scaled lime; saw dust, etc. and blown by machine or manually. It is effective in dense vegetation.

·         D.D.T (dichloro diphenyl trichloro ethane) – This is a white crystalline powder. It is used as 5-10% oily solution by spraying, or in 10% concentration if used as dust. It is used in the following forms –

·         D.D.T aromax emulsion consisting of D.D.T, aromax, soap flakes and water. It is sprayed.

·         D.D.T kerosene oil

·         Pyrethrums extract 4%, D.D.T and kerosene oil. This is also sprayed.

·         D.D.T in aerosols. The aerosol contains.4% pyrethrum, 3% D.D.T, 5% cycle hexane, 5%sesame oil.

·         Gammaxene or benzene hexa chloride (B.H.C). This is gammaxene P520 (water dispersible powder) and water in suspension and is sprayed.

Flies

·         Prevention of breeding of flies – It aims at prompt removal and disposal of all refuse. All garbage, kitchen wastes and similar refuse should be placed in garbage receptacles. For destruction of eggs, larvae and pupae of flies, powdered borax can be applied in solution.

·         Protection of food from flies.

·         Destruction of adult flies

·         By flytraps

·         Poisonous baits maybe used. 2% formalin solution with sugar and milk maybe used. Or sodium arsenate solution maybe used.

·         Spraying D.D.T, pyrethrum in kerosene, giolderin, chlordane or B.H.C will readily kill flies.

Carpet beetles

·         These are 2-4mm long like small mottled brown, gray and cream ladybirds. Adults are often seen from April – June, seeking places to lay their eggs. The larvae are most active in October before they hibernate. The adult beetle feds on pollen and nectar of flowers, but lays it’s nest in old nests of birds, fabrics and accumulated fluff in buildings. The larvae that hatch from eggs do the damage by feeding on feathers, fur, hair, wool or articles made from those substances. Carpet beetles are now the major hostile pests and do more damage than moths.

·         The life cycle takes about a year and the larvae can survive for several months without food.

·         Frequent vacuum cleaning of fluff and debris from storage cupboards, floorboards, carpets and upholstery is the main means of control. Insecticide maybe sprayed between floorboards, under carpets, under felts and in the crevices.

Wood burring beetles

·         The common furniture beetle lays about 20-60 eggs in cracks and crevices of unfurnished wood. On hatching, the grub eats it’s way through the wood and this tunneling causes weakening of the wood and may take form 2-3 yrs. Eventually the grub matures, bores towards the surface of the wood and changes into pupa. From this emerges the beetle which bites it’s way into the open air through an exit hole which is about.15 cm in size. The beetles have a very short life of 2-3 weeks.

·         If small piles of bore dust beneath the holes indicate presence of active worms in the wood and treatment is necessary.

·         Eggs are laid in unpolished wooden surfaces, so the use of shellac, varnish, lacquer or polish acts as a deterrent. To kill woodworm, the exit holes should be sprayed, brushed or injected several times with antokil, usprinol, pyrethrum, etc. There are other treatments such as blowing poisonous gases. A badly infested piece of wood is better burnt.

Moths

·         Clothes and house moths are of pale buff colour and are seen flying mainly between June and October. They rarely live longer than a month.

·         The female lays its eggs (approx. 200 at a time) in some dark warm place, on material that later the grubs (pupae) can eat. Once the eggs hatch, the grubs immediately feed on the material the move about. When fully grown they crowd into sheltered places and spin a cocoon around themselves and become chrysalis (pupae). They later emerge as moths and start another lifecycle. The entire lifecycle varies from 1 month to 2 yrs.

·         The materials that are attacked by moth (the grubs) are wool, fur, skin and feather. They are immune to rubber, man-made or vegetable fibers. While feeding on these materials, the grubs form small holes in the articles and damage occurs frequently during the storage, because of the warmth, darkness and lack of disturbance.

·         It is always advisable that articles to be stored should be clean, protected by moth deterrent and inspected frequently. Calmly used moth deterrents are naphthalene, camphor tablets, Para dichlorobenzene, pyrethrum, etc. Temperatures of 60 degrees C and above will destroy grubs and eggs. Infested articles such as upholstered furniture may be treated by heat or may be fumigated.

Rats and mice

·         Rats and mice are more likely to be found in kitchens and dining rooms than in bedrooms. Scraps of food, candles, soaps, etc attract them. Hygienic storage; disposal of food of all kinds of waste; and cleanliness of all areas where food is handled are important to prevent an infestation.

·         Rat’s destruction: –

1.      By poisonous baits – Baits consists of an inner base to which some poison is added. The common bases are flour, bread, sugar, etc. the most common poison used is barium carbonate. Other poisons are white arsenic, phosphorus, zincphosphide, alphanaphnyl thiourea, sodium fluro acetate (1080) and dicoumarine (warfarin).

2.      By fumigation – This is a very effective method and should be carried out by a trained squad. Cyanogas ‘A’ dust or cymag is used. The other gases which are used are carbon monoxide, carbon dioxide, sulphur dioxide.

3.      By trapping – Generally wire cage traps are used for the purpose. Trapped rats are transferred everyday to the collecting cage, which is taken to the disposal station where the rats are drowned by immersing the whole cage in a tub containing phenyl or water.

Wood Rot



Dry Rot

·         This is the term used for the decay of timber by a fungus which grows and lives on wood; and reduces it finally to a dry crumbling state – hence the name dry rot. It starts in damp (more than 20% moisture) unventilated places and spreads by sending out thin root like strands that creep over brickwork to attack the surrounding wood. Once a fungus gets hold, it produces fruit bodies. The spheres are produced in enormous numbers and are so small that they move as reddish brown dust, which may be blown about easily, to great distances.

·         Dry rot can be recognized by its offensive, mouldy smell; by it’s friable condition and the ‘dead’ sound when the wood is hit with a hammer. When a rot occurs it is necessary to find the reason for the dampness of the wood.

·         Having ascertained and cured the cause of dampness, all rotten wood must be thrown out 20-30 cms beyond the infested area and burnt. All brickwork near the infested wood should be sterilized by the use of a blowlamp and when cool, treated with a preservative  before repairing.

Wet Rot

·         This is the name given to the fungus decay in timber in very damp situations. The fungus usually involved is the cellar fungus and it attack timber when it is wet. It requires considerably more moisture for development than dry rot fungus (approx. 40-50% of the dry weight of the wood).

·         The fungus causes the darkening of the wood, which breaks up into small rectangular pieces on drying. There is usually a thin skin of sound wood left on the surface of the timber, but rarely is there any evidence of fungus growth.

·         Since the fungus requires relatively wet timber, it’s eradication is much more simple than in case of dry rot. Growth can be checked at once if the timber is thoroughly dried and the source of moisture removed. Badly decayed wood should be cut out and replaced with a fungicide.

Problems associated with pests

·         All pests carry food poisoning bacteria in their droppings, and also on their fur, feathers and feet. They therefore contaminate the food they eat, any exposed food they climb over, and any work surfaces that they run over.

·         Rats and mice need to wear down their incisor teeth, which grow continuously. To do this they gnaw woodwork, gas and water pipes, and electric cables, often with disastrous consequences.

·         Cockroaches leave a characteristic and very unpleasant smell. They like warm, moist areas where they will be undisturbed and are often found behind ovens and hot water pipes. They are able to squeeze through very narrow gaps and generally emerge only when it is dark.

·         Flies feed on a wide variety of matters including infected waste food and animal faeces. They pick up large number of food poisoning bacteria, which they transfer to human food when they land on it. While they are feeding they deposit faeces on food. They also vomit saliva on to the food to digest it partially before sucking it up again.

·         Bird droppings make buildings look dirty and ugly. They can also damage the structure of the building. Birds nest block gutters, causing overflows, which may lead to structural damage.

Control of pests

·         In any kitchen where flies are likely to be a problem, an electrically operated fly killer should be fitted. This consists of an ultraviolet light that attracts flies and other flying insects to a metal grid with an electric current running through it. The flies are electrocuted when they touch the metal grid and fall into a collecting tray underneath. The tray must be emptied and cleaned on a regular basis to ensure that dead flies do not drop into food being prepared below.

·         Rats and mice are usually eliminated with poison housed in a tamper-resistant bait box that reduces risks of poison getting into food products. Rats are very suspicious animals and baiting is necessary for at least two weeks before they will take any poisoned food.

·         Cockroaches and other insect infestations are usually treated with insecticide sprays.

·         Birds are encouraged to eat food mixed with a narcotic drug that causes deep sleep. They are then removed.

Maintenance

·         As previously indicated, pest control begins with an organized inspection procedure, which should be conducted with a flashlight and screwdriver to permit observation into dark and hidden areas, such as behind the equipment or baseboards.

·         When looking for pest activity, it is not necessary to observe only live insects or rodents. Rodents may leave rub marks on wall or floor joists as they travel. Insect and rodent droppings, as well as damaged food containers, are another sign of infestation. Roaches, for example, may leave eggs, skin, and body parts.

·         Inspections of equipment should include lifting up shelves, pulling out drawers, looking behind cabinets, removing panels and filters, looking behind sinks, into lighting fixtures, and looking above false ceilings.

·         Dining area inspections should include checking under tables, removing and inspecting booth cushions, and carefully examining service stations.

·         The exterior of a building should be inspected for cracks or openings that might permit the entry of rodents or other pests; for proper containers and general cleanliness of refuse areas; and for properly screened air ducts and any accumulation of debris on roof top equipment.

·         A particular threat to wooden structures or wooden framed structures is the termite, which eats the interior of wood. Their presence in a building may not be suspected until the winged forms appear. If an infestation appears, steps should be taken to block the termites from the building. The most effective and permanent means of accomplishing this objective is to make structural changes that will insulate all woodwork from the ground and allow proper ventilation of all excavated areas enclosed by the foundation. All wood that has been structurally weakened should be replaced.

·         A rodent control program is most effective when provisions are made to permanently exclude rodents from the building. As previously mentioned, the first step towards rodent control is through survey of building premises. Door that might be left open in the night should have self-closing devices. Special attention should be given to any cracks and crevices, such as the small openings around pipes. Even after sealing, rodents can enter the building in shipments of supplies. Thus the most effective known means of destroying rodents is with chemicals. Each type of rodenticide has specific instructions as to its application. Since rodenticide is effective only when ingested, careful preparation and application are necessary.

Storage

·         When mixing pesticides carefully review the label directions and protect the skin from contact with the chemical by procedures such as wearing rubber gloves during mixing, and standing upwind of the mixing container.

·         A basic character of pesticide storage area should be a locked or limited access. The entrance to such storage areas should be labeled with a sign bearing the caution “Pesticides Stored Here. Keep Out”.

·         Pesticides are best stored in their original containers, which should be inspected periodically for leaks and tears. To keep the label intact and legible, cover it with transparent tape or lacquer.

·         Although pesticides are manufactured, formulated, and packaged to exacting standards, they can deteriorate in storage, especially under conditions of high temperature and humidity.

·         Certain pesticide chemicals have characteristic odour. If this odour grows stronger in the storage area, it may indicate a leak, spill, or defective container or deterioration.

·         Storage temperatures affect the shelf life of pesticides. Ideal storage conditions are cool, dry and out of sunlight. Below freezing temperature causes some liquid formulations to separate into various components, resulting in a loss of their effectiveness. High temperatures cause many pesticides to become volatile or break down more rapidly and glass containers to burst.

·         With proper storage pesticide products can be carried over for several years. Because shelf life is difficult to predict, pesticide manufactures do not guarantee products stored longer than two years.

Precautions to be taken while handling pesticides

·         All pesticides are toxic to humans. Food service workers need to be adequately instructed regarding the hazards involved & should be trained to avoid them.

·         These are some of the precaution needed:

·         Using gloves & masks while handling these chemicals is essential

·         Wash hands thoroughly after use.

·         Never use sprays when food is openly displayed.

·         Storage of insecticides away from food articles. Holding these poisons in a separate area with their proper labels is important to avoid accidental poisoning. Also they are to be kept away from heat and open flames.

·         Knowledge of the type of pesticides banned & the specific residual limits permissible in food commodities as laid down by the Govt. of India is essential.

·         First-hand knowledge of anti-dotes to various poisons is necessary for food service workers.

Areas of Infestation

Pest infestations are one of the major reasons for prosecutions in the catering industry. There are three main groups of pests commonly found in food premises.

·         Rodents: mainly rats and mice

·         Insects: mainly flies and cockroaches

·         Birds: mainly sparrows, pigeons and starlings.

Signs of infestations

·         Food handlers should not try to deal with pest infestations themselves, but must be able to recognize when pests are present so that they can call in professional help immediately. The following are all signs of infestations.

1.      Live or dead rodents, insects or birds

2.      Droppings

3.      Gnawing marks

4.      Torn packets, paper sacks or cardboard boxes

5.      Grease marks on skirting boards

6.      Footprints on dust

Preventive measures and Control measure

Pest Control Methods:-

       1.      Prevention – keeping a pest from becoming a problem.

       2.      Suppression – reducing pest numbers or damage to an acceptable level.

       3.      Eradication – destroying an entire pest population.

Threshold Level: These are the levels of pest population beyond which pest control action should be taken to prevent the pest in an area from causing unacceptable injury or harm. These are also known as “Action Threshold”.

General Preventive Measures

        · A clean well-ventilated environment cuts down the possibility of pests.

        · Remove waste as early as possible.

        · Periodic and spring cleaning.

        · Good building maintenance.

        · Eliminating potential breeding sites

       · Pest control

       · Self

       · On contract-Usually hotels hire professional pest control companies on the service contract. These companies visit the premises on a regular basis and check for any problem areas and take preventive measures.

       · Frequency of pest control   

       · Alternate days – spraying of insecticides – open areas

       · Fortnightly –spraying of insecticide –  In front of the house, back of the house and floors

       · Once in six months/ year – Fumigation – entire areas including rooms and kitchens

       · If at any time there are signs of infestation special treatment is done in the specified area to prevent its spread.

       · Flies, mosquitoes, ants and moths can be killed with spray insecticides. This can be done when the guest is not there in the room and well before service in bars and restaurants. Entry to these is also prevented by double doors at all entrances and exits. Also, use of air curtains.

       · Spray of special insecticides against flying and crashing insects.

       · Fumigation at regular intervals eliminate the pest

       · Against mosquitoes there are small electric machines which heat up; a special tablet placed on it gives off a vapor that kills them.

       · On terraces, one can use mosquito coils.

       · Curtain open-air restaurants supply a spray which one can spray on legs or arms to deter mosquitoes.

       · Hotels with large gardens usually spray the garden areas against flies in the morning and against the mosquitoes in the evening.

SELF ASSESSMENT

Q.1) What are pests? Name five pests encountered in hotels. Enumerate the importance of pest control.

Q.2) What are pests? Why is their control important?

Q.3) Discuss areas of pests infestation in a hotel and preventive measures.
Q.4) Name different types of pestsfound in hotel atmosphere. Explain how pest control is carried out in hotels.