SECTION 2: Health and nuisance pests - general
Every rand spent on health and nuisance pest control will, most likely, return additional rands in reduced damage, harm to health and, in food establishments, product losses. This fact quickly illustrates that managing pests is actually an investment and not an expenditure!
Insects, rodents, birds, and other health and nuisance pests cause extensive damage to our food, health, and property each year. Losses resulting from insect and rodent damage to stored food alone exceed billions of rands annually. Many pests also transmit disease. Cockroaches, flies, mosquitoes, ticks, fleas, rodents, and birds are directly involved in the transmission of such diseases as food poisoning, malaria, typhus, viral encephalitis, plague, and Lyme disease. Other pests bite or sting or cause allergic reactions in the indoor environment. Finally, pests living in and around buildings are objectionable to most people simply by their presence, detracting from the overall quality of life.
Pest management strategies need to be continually evaluated to ensure that the needs of the entire program are met. There must, however be a diverse network of communication so that problems can be anticipated and dealt with effectively. Remember, professional pest management can only work when there is cooperation and communication between the customer and PCO.
2.2 Principles of Pest Control
2.2.1 Health & Nuisance Pests
A pest is anything that:
- Competes with humans, domestic animals, or desirable plants for food or water
- Injures humans, animals, desirable plants, structures, or possessions
- Spreads disease to humans, domestic animals, wildlife, or desirable plants – i.e. harmful to health
- Annoys humans or domestic animals – i.e. is a nuisance
188.8.131.52 Types of Health & Nuisance Pests
Types of health and nuisance pests include:
- Insects, such as cockroaches, mosquitoes, beetles, fleas, and flies
- Insect-like organisms, such as mites, bedbugs, lice, ticks, and spiders
- Vertebrates, such as rats, mice, birds, bats, and snakes
Most organisms are not pests. A species may be a pest in some situations and not in others. An organism should not be considered a pest until it is proven to be one.
2.2.2 Pest Identification
Accurate identification is the first step in an effective pest management program. Never attempt a pest control program until you are sure of what the pest is. The more you know about the pest and the factors that influence its development and spread, the easier, more cost-effective, and more successful your pest control will be. Correct identification of a pest allows you to determine basic information about it, including its life cycle and the time that it is most susceptible to being controlled. (The back of this manual contains information to assist in identification of pests).
As a certified applicator, you must be familiar with the pests you are likely to encounter in the type of work in your certification category.
To identify and control pests, you need to know:
- The physical features of the pests likely to be encountered
- Characteristics of the damage they cause
- Their development and biology
- Whether they are continuous, sporadic, or potential pests
- What your control goal is
2.2.3 Pest Control
Any time you are considering whether pest control is necessary, remember:
- Control a pest only when it is causing or is expected to cause more harm than is reasonable to accept.
- Use a control strategy that will reduce the pest numbers to an acceptable level.
- Cause as little harm as possible to everything except the pest.
Even though a pest is present, it may not do much harm. It could cost more to control the pest than would be lost because of the pest's damage.
2.2.4 Pest Control Goals
Whenever you try to control a pest, you will want to achieve one of these three goals, or some combination of them:
- Prevention - keeping a pest from becoming a problem
- Suppression - reducing pest numbers or damage to an acceptable level
- Eradication - destroying an entire pest population
Prevention may be a goal when the pest's presence or abundance can be predicted in advance. Continuous pests, by definition, are usually very predictable. Sporadic and potential pests may be predictable if you know the circumstances or conditions that favour their presence as pests.
A preventive pest control program must include:
- Bird control procedures
- Insect control procedures and schedule
- Rodent control procedures and schedule
- Pesticide application records
- Comprehensive inspection program
Suppression is a common goal in many pest situations. The intent is to reduce the number of pests to a level where the harm they cause is acceptable. Once a pest's presence is detected and control is deemed necessary, suppression and prevention often are joint goals. The right combination of control measures can often suppress the pests already present and prevent them from building up again to a level where they are causing unacceptable harm.
Eradication is a rare goal in outdoor pest situations because it is difficult to achieve. Usually the goal is prevention and/or suppression. Eradication is occasionally attempted when a foreign pest has been accidentally introduced, but is not yet established in an area. Such eradication strategies often are supported by the government. The Mediterranean fruit fly, gypsy moth, and fire ant control programs are examples.
Eradication is a more common goal indoors. Enclosed environments usually are smaller, less complex, and more easily controlled than outdoor areas. In many enclosed areas, such as dwellings, schools, office buildings, and health care, food processing, and food preparation facilities, certain pests cannot or will not be tolerated.
2.2.5 Threshold Levels
Thresholds are the levels of pest populations at which you should take pest control action if you want to prevent the pests in an area from causing unacceptable injury or harm. Thresholds may be based on aesthetic, health, or economic considerations. These levels, which are known as "action thresholds," have been determined for many pests.
A threshold often is set at the level where the economic losses caused by pest damage, if the pest population continued to grow, would be greater than the cost of controlling the pests. These types of action thresholds are called "economic thresholds." For example, when the number of insects on a particular crop exceeds a given quantity, an insecticide application to prevent economic damage could be justified.
In some pest control situations, the threshold level is zero: even a single pest in such a situation is unreasonably harmful. For example, the presence of any rodents in food processing facilities forces action. In homes, people generally take action to control some pests, such as rodents or roaches, even if only one or a few have been seen.
2.2.6 Pest Monitoring
In most pest control situations, the area to be protected should be checked often.
Regular monitoring can answer several important questions:
- What kinds of pests are present?
- Are the numbers great enough to warrant control?
- When is the right time to begin control?
- Have the control efforts successfully reduced the number of pests?
Monitoring of insects, insect-like organisms, and vertebrate pests usually is done by trapping or by scouting.
Monitoring also can include checking environmental conditions in the area. Temperature and moisture levels, especially humidity, are often important clues in predicting when a pest outbreak will occur or will hit threshold levels.
Monitoring is not necessary in situations where a pest is continually present and the threshold is zero. For example, there is zero tolerance for bacteria in operating rooms and other sterile areas of health care facilities. In these situations, routine pest control measures are taken to eradicate any pests and to prevent pests from entering the area.
2.2.7 Avoiding Harmful Effects
Pest control involves more than simply identifying a pest and using a control tactic. The treatment site, whether it is outdoors or indoors, usually contains other living organisms (such as people, animals, and plants) and nonliving surroundings (such as air, water, structures, objects, and surfaces). All of these could be affected by pest control measures. Unless you consider the possible effects on the entire system within which the pest exists, your pest control effort could cause harm or lead to continued or new pest problems. Rely on your good judgment and, when pesticides are part of the strategy, on the pesticide labeling.
Most treatment sites are disrupted to some degree by pest control strategies. The actions of every type of organism or component sharing the site usually affect the actions and well-being of many others. When the balance is disrupted, certain organisms may be destroyed or reduced in number, and others - sometimes the pests - may dominate.
2.3 Diseases Caused by Pest-borne Pathogens
A number of arthropods and vertebrates have a magnified reputation and status as pests due to their involuntary participation in the spread of disease-causing organisms (pathogens and parasites) among humans and domesticated animals. Therefore, pest management professionals play an important role in preserving public health through their efforts in reducing or eliminating pest populations in both urban and rural settings. The importance of pest management in public health is often difficult to quantify due to:
- The effectiveness of pest management efforts in this country,
- The limited likelihood of sufficient exposure by a susceptible host to an infected or contaminated pest,
- Variability in the fraction of pest populations which actually carry pathogens,
- The high percentage of pest-borne and pest-vectored cases which go unreported or are misdiagnosed, and
- The potential for introduction of new pathogens from abroad and the occasional resurfacing and spread of existing (endemic) pathogens in select parts of the country.
Pest management professionals may never know how often their efforts have averted a public health disaster. However, for the sake of addressing the questions and concerns of an inquiring public and defending the reputation of a noble profession, they should be aware of the health conditions, causal pathogens and known carriers which pose a threat to the public well-being.
2.3.1 Pests and Public Health
Arthropods are probably the most successful of all animals. They are found in every type of habitat and in all regions of the world. They feed on a wide variety of plant and animal materials and have been known as major causes of disease for centuries. Insects are referred to in the Bible as well as in Chinese, Greek, Roman and other historical writings. Insect-transmitted diseases have killed more soldiers than all military actions combined. Fleas, lice and mosquitoes infect humans and domesticated animals directly or indirectly with the organisms of many dangerous diseases. Arthropod stings or bites are occasionally fatal to humans. Their germ-laden saliva or contaminated bodies also are potential sources of disease transmission. Arthropods, especially insects, are vital players in the transmission of certain diseases to humans.
2.3.2 Carriers and Vectors
Carriers are organisms (like cockroaches and house flies) that pick up pathogens (like Salmonella bacteria) on their tarsi and mouthparts and, during the course of contacting food and other items handled by humans, spread those pathogens by contamination.
Vectors are organisms (such as anopheline mosquitoes) which play an important role in the life cycle of certain pathogens (such as malaria-causing sporozoans, Plasmodium species). Vectors serve to transfer infective stages of a pathogen from one host to another or from an intermediate (reservoir) host to a definitive host, while providing acceptable conditions for their further development.
184.108.40.206 Vector-host Relationships
In considering transmission of disease-causing organisms, it is important to understand the relationships between the vector (the disease-transmitting organism, for example, an insect), the disease pathogen (the infecting organism, for example, a virus) and the human or animal host. Pathogens that undergo changes in life stages within the vector before being transmitted to a host require the vector. Without the vector, the disease life cycle would be broken and the pathogen would die. Some diseases that require an insect host may require several individual hosts before completing pathogen transmission.
In the various phases of the process, the hosts may be different species. PCOs can better design and manage control programs for a particular problem by understanding how a disease is transmitted and the involvement of vectors.
- Myiasis. Infestation of an animal, including humans, by living maggots deposited on the skin or in a wound by flies is termed “myiasis.” Some forms, such as bot flies, breed solely in this manner.
Mechanical transmission of disease. Mechanical transmission of disease pathogens occurs when a vector transports organisms, such as bacteria that cause dysentery, on its feet, body hairs and other body surfaces to the host. There is no multiplication or development of the pathogen within the vector’s body.
For example, the house fly, Musca domestica, is a passive (mechanical) transmitter of bacillary dysentery.
Mechanical transmission can be considered more or less accidental.
- Biological transmission of disease. Disease-causing pathogens need help to move from one host to another. Many ticks and insects are important vectors of biologically transmitted diseases. The arthropod acquires the pathogen from one host. The pathogen then develops in the arthropod’s body and is transmitted to another host. Within the arthropod, the pathogen may or may not multiply. If the pathogen or parasite that causes the disease undergoes the sexual portion of its life cycle in a host, that host is the primary or definitive host, as in the mosquito that harbours malaria. For malaria, a human is the intermediate host in which the asexual stages of the parasite are found.
Modes of biological transmission:
- Obligatory vectors. Obligatory vectors of disease include those in which the pathogen develops from one life-cycle stage to another. Malaria is an example of a disease that must be taken up by a vector (mosquito) to develop from one stage to another. Otherwise, the malaria parasite would die. Mosquitoes are often obligatory vectors of diseases.
- Reservoir hosts. Reservoirs are defined as one or more host species that harbour a disease-causing pathogen over an extended period of time without showing symptoms of the disease. Disease transmission can occur when a vector feeds on a host that carries the pathogen then feeds on another, susceptible host. Birds are an example of reservoirs for mosquito-borne encephalitis, which can affect humans, horses or other dead-end hosts - those from which susceptible mosquitoes cannot acquire an infection. In many cases the disease is endemic, that is, it exists continually in reservoirs in a geographically defined area. Diseases that cycle in nature to nonreservoir hosts without involving humans are called zoonoses. When a disease outbreak occurs in these nonhuman animals, it is called an epizootic.
- Transovarial transmission. Some vectors pass the disease to their offspring through eggs. When the female is infected with the disease organism, her eggs become infected and the resulting larvae are infected with the disease. The subsequent adult stage is then infected and can transmit the pathogen without needing to feed on an infected host. This occurs with several mosquito-borne viruses and with tick fever. In that instance the tick and the mosquito serve both as reservoir and vector.
2.3.3 Poison Irritation and Allergy
Many insects, some spiders, scorpions and centipedes have developed poisoning mechanisms to use in self-defence or in paralyzing their prey. Stings and bites may be intensely painful and irritating to humans but seldom cause death. Probably the most dangerous is the bite of the black widow spider, Latrodectus mactans. The brown recluse spider, Loxosceles reclusa, may inflict a serious bite, often resulting in so much dead tissue that skin-grafting is needed. There have been deaths reported from both spiders. Stings of bees and wasps may be serious or even fatal to people highly allergic to their venoms.
Other insects that can cause skin irritations to humans include certain moth and caterpillar species. These are not insects of direct health concern but are often topics of public inquiry.
2.3.4 Pests and Diseases
Many pests can spread diseases that are harmful to human health. Without proper management techniques, pests such as cockroaches, rodents, ticks, fleas and mosquitoes can cause severe damage and/or pose serious threats to human health.
- Insects spread disease. Malaria, which is a disease carried by Anopheles mosquitoes, kills over 1.5 million people in Africa every year, most of them children. Simulium flies in West Africa spread a disease to people called onchocerciasis which makes them go blind. Tsetse flies (Glossina) infect people with sleeping sickness which left untreated can result in death. If you swallow a flea in your house you run the risk of being infected with tapeworm. There are many other diseases transmitted between humans and between humans and animals by insects and in order to control the spread of these diseases we need to study the vector insects that spread them.
- Insects maim and kill our livestock. About 10 million km2 of Africa is affected by animal trypanosomiasis (nagana), spread by Tsetse flies (Glossina), which seriously limits farming efforts. For cattle to thrive in these areas, they need to be given drugs and/or the tsetse need to be controlled. The sheep blowfly Lucilia cuprina causes about a R20 million loss to the South African wool and mutton industries per year. Ticks (which are arachnids not insects) spread many livestock diseases and farmers in South Africa spend millions annually on pesticides to control them.
- Flies and cockroaches in particular spread diseases. Their free movement from dirty to clean areas enables them to carry infections on their bodies and mouthparts.
- Rodents carry a micro-organism that causes Leptospirosis. The micro-organism can survive in the rat without causing any illness. However if passed onto humans, either by direct contact or through contact with surfaces or water, which has been contaminated with rat's urine, the potentially fatal form of Leptospirosis, called Weil's disease, results.
- Rodents, insects and birds can contaminate food, equipment and working surfaces with excreta, hairs or body parts.
220.127.116.11 Pest-Related Health and Safety Issues
When sanitation issues are neglected – for example when waste is allowed to accumulate, especially if it contains food scraps, it will become an attraction for all kinds of pests, including; Rats, Mice, Flies & Maggots, Cockroaches, Birds and Ants.
Pests can transmit a host of diseases to humans and animals with effects ranging from minor discomfort to death. Diseases spread by pests include:
· bubonic plague
· lyme disease
· murine typhus
· typhoid fever
Recent studies show that pests, especially cockroaches, cause the most health problems for asthmatic children. In other words, they directly affect family, health, and home.
That’s because roach faeces, saliva, eggs, and outer covering, or cuticles, left behind on surfaces contain substances that are allergenic to humans, especially those with asthma or other respiratory conditions.
PCOs, by the very nature of their work, may place themselves at considerable risk while performing inspections and implementing control measures for pests that are known carriers or vectors of pathogens.
Let’s take a closer look at some of the diseases that you could encounter on the job.
2.3.5 Diseases Encountered on the Job
The purpose for this section is to identify and inform PCOs about several infectious diseases which they may encounter on the job. They are either bloodborne or airborne.
Bloodborne diseases include:
- Hepatitis B (HBV)
- Human Immunodeficiency Virus (HIV) which can cause Acquired Immune Deficiency Syndrome (AIDS)
Airborne diseases include:
- Tuberculosis (TB)
- Hantavirus which can cause Hantavirus Pulmonary Syndrome (HRS)
Hepatitis B Virus (HBV)
Hepatitis B Virus (HBV) has been found in all body secretions and excretions; however, only blood, saliva, semen and vaginal fluids have been shown to be infectious. Infection may be spread to PCOs through contamination of skin lesions, or by exposure of mucous membranes to infective blood. People at the highest risk of exposure are those in medical and dental fields. If a PCO might be exposed to blood contact while servicing an account, preventative measures would be advisable.
There are two types of inactivated vaccines against HBV. They are licensed and available commercially. Both are safe and highly protective against all known strains of HBV.
Human Immunodeficiency Virus (HIV/AIDS Virus)
Human Immunodeficiency Virus (HIV/AIDS Virus) can be transmitted from one person to another through sexual contact, sharing HIV-contaminated intravenous needles and through transfusion of infected blood or its components. There is no significant risk of transmission through routine social contact with infected people. Although the virus has been detected in saliva, tears, urine, and bronchial secretions, no transmission via contact with any of these fluids has ever been reported. There has not been any evidence to show that biting insects could transmit HIV. PCOs will not generally be at risk in the course of pest control activities.
There is no known immunization against HIV. Accidental cuts or punctures from needles or sharp objects have caused less than .5% of infections. However, care should still be taken when working in hospitals or medical facilities. Pay attention to BIO-HAZARD signs.
Tuberculosis (TB) is contracted by exposure to infectious TB bacilli in airborne droplet nuclei when people cough, sneeze or sing in close proximity of others. The two types of TB are pulmonary and laryngeal TB, laryngeal being highly contagious. Prolonged exposure to an infected person may lead to increased risk of infection. Infection through the mucous membranes or breaks in the skin may occur, however, this is a rare occurrence.
If there is a possibility of worker exposure to droplet nuclei from tuberculosis, proper precautions should be taken. PCOs should be informed by health care facilities if there is a chance of exposure while servicing. Infected subject(s) should be removed and isolated while being treated. BCG vaccinations of uninfected people can induce tuberculin sensitivity.
Hantavirus Pulmonary Syndrome (HPS)
Hantavirus Pulmonary Syndrome (HPS) was discovered in the region where New Mexico, Utah, Colorado, and Arizona join in May of 1993. Hantavirus strains fatal to humans have been carried and spread by the field mouse. Other human-lethal strains have been associated with cotton rats, pack rats and other small mice. It has been shown that the mice carry the disease, but are not affected by it. Transmission of the virus from rodents to humans is rare, and direct transmission from human to human has not been clearly substantiated. Hantavirus may be transmitted in airborne particles of dust from mouse droppings, but is more likely transmitted by rodent urine or faecal contamination of human food or eating utensils. So far, field mice are the most efficient carriers of this virus. About two-thirds of those who have developed the pulmonary symptoms (HPS) have died. Death has usually been very quick in fatal HPS cases. Hantavirus infection symptoms are like flu or the onset of a severe cold. In severe cases (i.e., HPS), the lungs fill with fluid and the victim may die of drowning. Onset is sudden. Unfortunately, there is no known cure, nor preventive vaccine to combat this virus. Hantavirus researchers feel that human HPS fatalities will remain rare; however, it is important to take precautions when dealing with mice, or any rodent infestation, or in cleaning up rodent nests or droppings.
Before working with rodents, their nests, or droppings:
- The areas should be sprayed with a disinfectant to help neutralize the pathogens such as Hantavirus
- Open all doors and windows to allow dust to escape
- If needed, a fan may be used to help with ventilation
- Wear protective clothing, such as rubber gloves, respirators with a High Efficiency Particulate Air (HEPA) filter with pore size of less than .3 microns, and disinfect gloves before removing them
- Disinfect all reusable traps, bait boxes or other items used in controlling rodent populations
- Dispose of all rodents and any cleaning materials in a sealed bag
Since PCOs are at greater risk of contracting this virus than the general public, it’s better to be safe than sorry.
Of all the viruses or diseases which the pest control operator faces, Hantavirus is one of the most important. In today’s society we should not take any such problems lightly. We are the protectors of health and property and this should start with our own personal health and safety. If there is ever a question as to any risks on a job site, talk with officials at that account.
Be informed to prevent mistakes.
We educate our clients - don’t forget to educate yourself!
The information provided above should serve as a reminder to inspectors and PCOs to exercise caution by wearing appropriate clothing and using the recommended personal protective equipment (PPE) while in close proximity to these organisms, their harbourages and nesting sites.
2.3.6 Recommended PPE
The following PPE and products are strongly recommended if working in potentially hazardous areas:
- Full-face or half-mask respirator fitted with a HEPA (="P-100") filter
- Disposable latex or vinyl gloves
- Clean, long-sleeve overalls
- Disinfectant (sprayable liquid)
- Pest vacuum cleaner fitted with a HEPA filter
- Plastic garbage bags and ties
- Soap, clean water and paper towels
- A proven insect repellent product
2.3.7 Integrated Pest Management
Integrated pest management is the combination of appropriate pest control tactics into a single plan to reduce pests and their damage to an acceptable level. Using many different tactics to control a pest problem tends to cause the least disruption to the living organisms and nonliving surroundings at the treatment site. Relying only on pesticides can cause pests to develop resistance to pesticides, outbreaks of other pests, and can harm surfaces or non-target organisms. With some pests, using pesticides alone will not achieve adequate control.
To solve pest problems, you must:
- Identify the pest or pests and determine whether control is warranted for each
- Determine your pest control goal(s)
- Know what control tactics are available
- Evaluate the benefits and risks of each tactic or combination of tactics
- Choose a strategy that will be most effective and will cause the least harm to people and the environment
- Use each tactic in the strategy correctly
- Observe local, state, and federal regulations that apply to the situation
The strategy you choose will depend on the pest you have identified and the kind and amount of control you need.
18.104.22.168 Natural Controls
Some natural forces act on all organisms, causing the populations to rise and fall. These natural forces act independently of humans and may either help or hinder pest control. You may not be able to alter the action of natural forces on a pest population, but you should be aware of their influence and take advantage of them when possible. Natural forces that affect pest populations include climate, natural enemies, natural barriers, availability of shelter, and food and water supplies.
- Climate - Weather conditions, especially temperature, day length, and humidity, affect pest activity and rate of reproduction. Pests may be killed or suppressed by rain, freezing temperatures, drought, or other adverse weather. Climate also affects pests indirectly by influencing the growth and development of their hosts. A population of plant-eating pests is related to growth of its host plants. Unusual weather conditions can change normal patterns so that increased or decreased damage results.
- Natural enemies - Birds, reptiles, amphibians, fish, and mammals feed on some pests and help control their numbers. Many predatory and parasitic insect and insect-like species feed on other organisms, some of which are pests. Pathogens often suppress pest populations.
- Geographic barriers - Features such as mountains and large bodies of water restrict the spread of many pests. Other features of the landscape can have similar effects
- Food and water supply - Pest populations can thrive only as long as their food and water supply lasts. Once the food source - plant or animal - is exhausted, the pests die or become inactive. The life cycle of many pests depends on the availability of water.
- Shelter - The availability of shelter can affect some pest populations. Overwintering sites and places to hide from predators are important to the survival of some pests.
22.214.171.124 Applied Controls
Unfortunately, natural controls often do not control pests quickly or completely enough to prevent unacceptable injury or damage. Then other control measures must be used.
Those available include:
- Host resistance
- Biological control
- Cultural control
- Mechanical control
- Chemical control
- Host resistance - Some plants, animals,
and structures resist pests better than others. Some varieties
of plants, wood, and animals are resistant to certain pests.
Use of resistant types, when available, helps keep pest
populations below harmful levels by making conditions less
favourable for the pests.
Host resistance works in three ways:
- Chemicals in the host repel the pest or prevent the pest from completing its life cycle.
- The host is more vigorous or tolerant than other varieties and thus less likely to be seriously damaged by pest attacks.
- The host has physical characteristics that make it more difficult to attack.
- Biological control - Biological control
involves the use of natural enemies - parasites, predators, and
pathogens. You can supplement this natural control by releasing
more of a pest's enemies into the target area or by introducing
new enemies that were not in the area before. Biological
control usually is not eradication. The degree of control
fluctuates. There is a time lag between pest population
increase and the corresponding increase in natural controls.
But, under proper conditions, sufficient control can be
achieved to eliminate the threat to the plant or animal to be
Biological control also includes methods by which the pest is biologically altered, as in the production and release of large numbers of sterile males and the use of pheromones or juvenile hormones.
Pheromones can be useful in monitoring pest populations. Placed in a trap, for example, they can attract the insects in a sample area so that pest numbers can be estimated. Pheromones also can be a control tool. Sometimes a manufactured copy of the pheromone that a female insect uses to attract males can be used to confuse males and prevent mating, resulting in lower numbers of pests. Applying juvenile hormones to an area can reduce pest numbers by keeping some immature pests from becoming normal, reproducing adults.
- Cultural control - Cultural practices
sometimes are used to reduce the numbers of pests that are
attacking cultivated plants. These practices alter the
environment, the condition of the host plant, or the behaviour
of the pest to prevent or suppress an infestation. They disrupt
the normal relationship between the pest and the host plant and
make the pest less likely to survive, grow, or reproduce.
Common cultural practices include rotating crops, cultivating the soil, varying time of planting or harvesting, planting trap crops, adjusting row width, and pruning, thinning, and fertilizing cultivated plants.
- Mechanical (physical) control - devices,
machines, and other methods used to control pests or alter
their environment are called mechanical or physical controls.
Traps, screens, barriers, fences, nets, radiation, and
electricity sometimes can be used to prevent the spread of
pests into an area.
Lights, heat, and refrigeration can alter the environment enough to suppress or eradicate some pest populations. Altering the amount of water, including humidity, can control some pests, especially insects and disease agents.
- Sanitation - sanitation practices help to
prevent and suppress some pests by removing the pests or their
sources of food and shelter. Urban and industrial pests can be
reduced by improving cleanliness, eliminating pest harbourage,
and increasing the frequency of garbage pickup. Management of
pests attacking domestic animals is enhanced by good manure
management. Carryover of agricultural pests from one planting
to the next can be reduced by removing crop residues.
Other forms of sanitation that help prevent pest spread include using pest-free seeds or transplants and decontaminating equipment, animals, and other possible carriers before allowing them to enter a pest-free area or leave an infested area. The proper design of food-handling areas can reduce access and shelter for many pests.
- Chemical control - Pesticides are chemicals used to destroy pests, control their activity, or prevent them from causing damage. Some pesticides either attract or repel pests. Chemicals that regulate plant growth or remove foliage also are classified as pesticides. Pesticides are generally the fastest way to control pests. In many instances, they are the only tactic available.
2.3.8 Pest Control Failures
Sometimes you may find that even though you applied a pesticide, the pest has not been controlled. You should review the situation to try to determine what went wrong. There are several possible reasons for the failure of chemical pest control.
126.96.36.199 Pest Resistance
Pesticides fail to control some pests because the pests are resistant to the pesticides. Consider this when planning pest control programs that rely on the use of pesticides. Rarely does any pesticide kill all the target pests. Each time a pesticide is used, it selectively kills the most susceptible pests. Some pests avoid the pesticide. Others withstand its effects. Pests that are not destroyed may pass along to their offspring the trait that allowed them to survive.
When one pesticide is used repeatedly in the same place against the same pest, the surviving pest population may be more resistant to the pesticide than the original population was. The opportunity for resistance is greater when a pesticide is used over a wide geographic area or when a pesticide is applied repeatedly to a rather small area where pest populations are isolated. A pesticide that leaves a residue that gradually loses its effectiveness over time will help select out resistance. Rotating pesticides may help reduce the development of pest resistance.
188.8.131.52 Other Reasons for Failure
Not every pesticide failure is caused by pest resistance. Make sure that you have used the correct pesticide and the correct dose and that you have applied it correctly. Sometimes a pesticide application fails to control a pest because the pest was not identified correctly and the wrong pesticide was chosen. Other applications fail because the pesticide was not applied at an appropriate time - the pest may not have been in the area during the application or it may have been in a life cycle stage or location where it was not susceptible to the pesticide. Also remember that the pests that are present may be part of a new infestation that developed after the chemical was applied.
2.4 The IPM Concept
2.4.1 Definition of Integrated Pest Management (IPM)
IPM is a long-standing, science-based, decision-making process that identifies and reduces risks from pests and pest management related strategies. It coordinates the use of pest biology, environmental information, and available technology to prevent unacceptable levels of pest damage by the most economical means, while posing the least possible risk to people, property, resources, and the environment. IPM provides an effective strategy for managing pests in all arenas from developed residential and public areas to wild lands. IPM serves as an umbrella to provide an effective, all encompassing, low-risk approach to protect resources and people from pests.
2.4.2 Origin of the term IPM
The phrase, integrated pest [population] management, was used in entomology literature in 1967. It was based on a concept termed integrated control, which had been previously developed by entomologists. The exact term “integrated pest management” and the IPM acronym entered the public arena and found its way into mainstream scientific literature in 1972 in both, a paper from President Nixon’s administration to congress and in a report from the Council on Environmental Quality entitled Integrated Pest Management.
IPM is often mistakenly associated only with entomology and insect pests. However, in contrast to entomology, plant pathology has, since its beginning, approached plant pests through multiple, or integrated strategies. The terminology traditionally used by plant pathologists was typically “tactics”. These traditionally-used tactics included rotation, pathogen-free seed, and genetic host resistance. However, in 1975 the federal USDA Cooperative Extension Service (CES) funded IPM programmes in every state and at this point the term, IPM, became commonly used in plant pathology literature also.
Kogan in the journal article, IPM History, details the components of the acronym, IPM, as it was generally accepted during the time of its entry into scientific and public nomenclature in the early 1970’s, as:
- “‘Integration meant the harmonious use of multiple methods to control single pests as well as the impacts of multiple pests”
- “‘Pests were any organism detrimental to humans, including invertebrate and vertebrate animals, pathogens, and weeds”
- “Management referred to a set of decision rules based on ecological principles and economic and social considerations”
Kogan also noted that IPM is a multidisciplinary (e.g. entomology, plant pathology, weed science, etc.) effort.
2.4.3 Developement of the IPM concept
Before World War II and the accompanying widespread use of organo-synthetic chemicals agricultural pest problems were commonly managed using cultural practices and information on pest lifecycles and biology. However, developement and use of organo-synthetic chemicals changed the focus to pest management by chemical means.
During the late 1950’s and early 1960’s increasing levels of chemical resistance in insect populations and pesticide injury to non-target organisms became evident and caused concern. These problems were brought about by reliance on insecticides for insect control. Entomologists began to develop and foster the concept of IPM. Ecological issues relating to the use of pesticides were also emerging during this time and also highlighted the need for a re-evaluation of reliance on chemical pest control. Meanwhile new developements in computer science, along with the emerging sciences of operations research, systems analysis, and modelling, allowed more sophisticated, multi-level, integrated approaches to pest management to emerge. The concept of IPM began to gain interest among researchers, extension personnel, agricultural stakeholders, the government and the public.
2.4.4 Structural IPM in an Urban Environment
Pests are not pests because of what they are (bedbug, yellow Jacket), but because of what they do (suck blood, sting). Urban pests can be generally characterized as organisms (excluding parasitic micro-organisms) which have human health or aesthetic implications, or which damage wooden support structures of buildings. These pests can be contrasted from agricultural pests that cause direct economic damage to products. For instance, while roaches or rodents may cause an economic hardship, when restaurants or food packing plants are closed by the legal action, the action is taken for reasons of human health. Likewise, carpet beetles in woollens or museum tapestries degrade clothing or works of art, but the reduction of value of the pieces is primarily for aesthetic reasons not due to consumption of woven wool.
Defined by the way they behave in an environment, or ecosystem, pests occur as a group, or population of individuals of a particular kind (e.g., German cockroaches). Different populations that exist together are called a community. One community may be fleas, pets, and people. A community together with its physical and biological supporting factors makes up the ecosystem (e.g., German cockroaches, fleas, people, pets, harbourage [areas with food, water, and shelter]). The PCO does not look at the pest infestation alone but must consider all elements in the ecosystem to design the best control and management methods.
2.4.5 Moving away from pesticides
Modern pest control has evolved into a complex and specialized discipline that includes the application of pesticides. Chemicals are still important, but property managers are now faced with increasing public concern about pesticide misuse, toxic materials in the workplace, and increasingly restrictive regulation. Safer chemicals and treatment methods are continually being developed and should be incorporated into pest control programmes whenever needed. At the same time, programme managers must be aware that numerous products are ineffective or require special skills to be used effectively.
CONTRASTS BETWEEN OLD-FASHIONED PEST CONTROL AND IPM FOR PEST CONTROL
Old-fashioned pest control
Integrated Pest Management
Preventive pest control
Routine pesticide application
Pesticides used when exclusion, sanitation, etc. are inadequate
Inspection and monitoring
Insecticides in occupied spaces
Application of sprayed insecticides
Mostly crack and crevice
Use of insecticide space spraying & fogging
Emphasis on rodenticide
Emphasis on trapping, sanitation and exclusion
Emphasis on avicide
Emphasis on exclusion
- The old-fashioned type of pest control that consisted of spraying around buildings and chasing cockroaches from one place to another is ineffective, potentially hazardous, and poses an unacceptable liability and public relations risk.
Modern pest management begins with the planning, design and maintenance of buildings.
- Once buildings are constructed, inspections often reveal pest problems.
- All personnel responsible for cleaning and solid waste management programmes must contribute to effective pest management. IPM is truly a multi-disciplinary function.
2.4.6 Attributes of IPM programme
The following are attributes of a general IPM programme:
- Proactive Programme
Old-fashioned pest control methods tended to ignore the causes of pest problems, and instead reacted and temporarily removed a small part of the infestation with chemicals. Although IPM also includes an immediate corrective response that may employ pesticides, it is mainly a preventive maintenance process that controls pests by reducing their food, water, harborage, and entry points. Hence, it is imperative that IPM begin with the structural planning and design process.
- Management Process
Old-fashioned pest control relied on the "exterminator" to solve pest problems, often without a pest management professional determining what services were needed and the type of control desired.
- Lasting solutions usually depend on coordinated initiatives to upgrade sanitation, housekeeping and repair.
Old-fashioned pest control consisted of routine pesticide application whether pests were present or not. IPM consists of routine inspection and monitoring, but treatment only when pests are actually present. Scheduled, repetitive pesticide treatment without regard for pest population dynamics is ineffective and environmentally unsound. IPM can reduce the potential for liability resulting from ecological insults or adverse effects on human health.
Non-chemical control alternatives should always be considered before the use of pesticides. Old-fashioned pest control included the application of excessive amounts of pesticides to exposed areas far from where needed. Baseboard spraying and room fogging is still widely practiced by some in the pest control industry. These techniques are not very effective for killing cockroaches and other insects that live deep within furniture, equipment, or structural elements. IPM requires that pesticides, when needed, be applied with precision and restraint. It emphasizes that only the safest compounds, formulations, and methods of application are appropriate. Insecticide baits are usually preferable to sprays. Sprays, when necessary, should be limited strictly to "crack and crevice" applications. Space sprays and fogging are reserved for unusual situations where no other solution is practical. Baits are the default method for controlling cockroaches and ants indoors.
Old-fashioned pest control technicians did little except operate compressed air sprayers. IPM requires a much higher standard of in-house and contractor expertise to be successful. It is essential that managers have informed technical guidance on all aspects of the pest control effort.
2.5 Advantages of integrating a range of control methods
The benefits of adopting an IPM approach – i.e. integrating a range of control methods include:
- Better Pest Control
Effectively applied, IPM programmes have been shown to provide better results and last longer than traditional pest control
- A Safer and Healthier Workplace
Both pests and pesticides pose health concerns for building occupants.
- Pests carry human pathogens and may produce potent human allergens.
- Building occupants may be exposed to pesticides through the air, or direct contact with treated surfaces.
IPM is being recognized by many experts as the best means to control pests effectively, while using the least amount of pesticide necessary. An increasing number of organizations, municipalities and schools are mandating that IPM programmes be implemented in their buildings.
Since IPM results in fewer pests than traditional pest control, it usually results in less pesticide used. However, whether IPM will reduce the amount of pesticide used in a building will in large be determined by what was being done for pest control before an IPM programme was implemented. Most facility managers report substantial reduction in pesticide use with IPM.
- Optimum Cost
Changes in cost, like pesticide use reduction, will in large part depend on what was done for pest control before an IPM programme was implemented. In many cases, IPM programmes result in similar or lower costs than traditional pest control programmes. Some pest control programme costs may rise initially when certain aspects of an IPM programme are put into place (such as structural modifications). Over time however, these costs usually balance out in terms of savings in pest control, or other budgets. Cultural controls and structural modifications applied for pest control purposes often have other benefits such as improved work environments, reduced energy costs, and reduced building maintenance.
- Better Public and Occupant Relations
IPM is a proactive method of controlling pests, which demonstrates that the pest control company and the facility management is environmentally conscientious and is concerned about the health of building occupants.