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.
