Integrated pest management (IPM) involves choosing appropriate tactics from a range of pest control techniques including biological, cultural and chemical methods to suit individual cropping systems, pest complexes and local environments. Biological control is often a component of an IPM strategy. It is defined as the reduction of pest populations by natural enemies and typically involves an active human role, such as augmentation which involves the supplemental release of natural enemies ( al,2010). Starting in the 1970s alternative forms of pest management have emerged. The term integrated pest management to the adoption of a linked set of (IPM) refers strategies, ranging from monitoring and the limited strategic use of pesticides, to the adoption of modified crops with refuges for beneficial insects. Included is the interaction with natural pheromone attractants, either for monitoring with traps, or for mating disruption (Card´e and Minks, 1995).

Integrated Pest Management (IPM) means the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms.

Need of IPM
Pesticides are among the most widely used chemicals in the world. Because of the widespread use of agricultural chemicals in food production, people are exposed to low levels of pesticide residues through their diets. With the intensification of agriculture over the last four decades, deterioration of soil structure and increases in soil pollution have emerged as major issues. Therefore, new farming management methods have been developed in order to replace conventional management which relies on heavy machinery and high rates of fertilizer and biocide application.

Pest outbreaks often cause serious ecological and economic problems, therefore, effectively controlling insects and other arthropods has become an increasingly complex issue over the past two decades. For example, locusts are important pests in warm, semiarid regions of the world. Farmers often use relatively simple techniques to control the increase in insect pests. Chemical insecticides have been used to control bands and swarms.

Pesticides are useful because they quickly kill a significant portion of a pest population (Zhang et al.2011).Pests have become resistant to many pesticides, rendering them less effective and causing farmers to increase pesticide dosage in attempts to achieve adequate pest control.The result has been pest resurgence, higher pest management costs, lower incomes, and greater risk of health and environmental problems(Nortan et al,1999).

In many parts of the world, agriculture causes environmental pressure that is significant on national scales. This is particularly true in terms of land degradation, water use and greenhouse gas emissions. The increase of environmental pressure from agriculture is unlikely to reverse in the near future, since the world population continues to increase faster than global food supply, and diets continue to shift towards animal products.(Wood et al,2006).Many studies have shown that conventional farming practices influence in a negative way the activity and biodiversity of soil fauna, especially earthworms and enchytraeids (Zwart and Brussaard, 1991).

In recent years there has been increased awareness by both consumers and agricultural producers of the need for reduced use of pesticide and protection of environment from the detrimental effects of agrochemicals. This implies the need for development ,diffusion and adaptation rational more pest control techniques( Ausher,1997).

Insecticides play a vital role in integrated pest management programme, but to be used in a rational and balanced way with least disruption of biota. Following principles and methodology may be adopted :instead of following
* routine treatment - insecticidal schedule,
* treatment when necessary, should be followed .

In order to achieve the goal of effective control of pests incorporating minimum quantum of insecticides based on "treat when necessary" principle in IPM. An American IPM system is designed around six basic components:

1. Acceptable pest levels: The emphasis is on control, not eradication. IPM holds that wiping out an entire pest population is often impossible, and the attempt can be expensive and environmentally unsafe. IPM programmes first work to establish acceptable pest levels, called action thresholds, and apply controls if those thresholds are crossed. These thresholds are pest and site specific, meaning that it may be acceptable at one site to have a weed such as white clover, but at another site it may not be acceptable. By allowing a pest population to survive at a reasonable threshold, selection pressure is reduced. This stops the pest gaining resistance to chemicals produced by the plant or applied to the crops. If many of the pests are killed then any that have resistance to the chemical will form the genetic basis of the future, more resistant, population. By not killing all the pests there are some un-resistant pests left that will dilute any resistant genes that appear.

2. Preventive cultural practices: Selecting varieties best for local growing conditions, and maintaining healthy crops, is the first line of defence, together with plant quarantine and 'cultural techniques' such as crop sanitation (e.g. removal of diseased plants to prevent spread of infection).

3. Monitoring: Regular observation is the cornerstone of IPM. Observation is broken into two steps, first; inspection and second; identification (Bennet,2005). Visual inspection, insect and spore traps, and other measurement methods and monitoring tools are used to monitor pest levels. Accurate pest identification is critical to a successful IPM program. Record-keeping is essential, as is a thorough knowledge of the behaviour and reproductive cycles of target pests. Since insects are cold-blooded, their physical development is dependent
on the temperature of their environment. Many insects have had their development cycles modeled in terms of degree days. Monitor the degree days of an environment to determine when is the optimal time for a specific insect's outbreak.

4. Mechanical controls: Should a pest reach an unacceptable level, mechanical methods are the first options to consider. They include simple hand-picking, erecting insect barriers, using traps, vacuuming, and tillage to disrupt breeding.

5. Biological controls: Natural biological processes and materials can provide control, with minimal environmental impact, and often at low cost. The main focus here is on promoting beneficial insects that eat target pests. Biological insecticides, derived from naturally occurring microorganisms (e.g.: Bt, entomopathogenic fungi and entomopathogenic nematodes), also fit in this category.

6. Responsible Pesticide Use: Synthetic pesticides are generally only used as required and often only at specific times in a pests life cycle. Many of the newer pesticide groups are derived from plants or naturally occurring substances (e.g.: nicotine, pyrethrum and insect juvenile hormone analogues), but the toxophore or active component may be altered to provide increased biological activity or stability. Further 'biology-based' or 'ecological' techniques are under evaluation. An IPM regime can be quite simple or sophisticated. Historically, the main focus of IPM programmes was on agricultural insect pests. Although originally developed for agricultural pest management, IPM programmes are now developed to encompass diseases, weeds, and other pests that interfere with the management objectives of sites such as residential and commercial structures, lawn and turf areas, and home and community gardens.

Process IPM is the intelligent selection and use of pest control actions that will ensure favourable economic, ecological and sociological consequences and is applicable to most agricultural, public health and amenity pest management situations(Sander et al,2006). Reliance on knowledge, experience, observation, and integration of multiple techniques makes IPM a perfect fit for organic farming (sans artificial pesticide application). For large-scale, chemical-based farms (conventional), IPM can reduce human and environmental exposure to hazardous chemicals, and potentially lower overall costs of pesticide application material and labour.

Risk assessment is usually characterized by four issues:
1) characterization and identification of biological control agents,
2) health risks,
3) environmental risks, and
4) efficacy.

1. Proper identification of pest - What is it? Cases of mistaken identity may result in ineffective actions. If plant damage is due to over-watering, it could be mistaken for fungal infection, since many fungal and viral infections arise under moist conditions. This could lead to spray costs, but the plant would be no better off.

2. Learn pest and host life cycle and biology. At the time you see a pest, it may be too late to do much about it except maybe spray with a pesticide(Robert et al,1994). Often, there is another stage of the life cycle that is susceptible to preventative actions. For example, weeds reproducing from last year's seed can be prevented with mulches and pre-emergent herbicide. Also, learning what a pest needs to survive allows you to remove these.

3. Monitor or sample environment for pest population - How many are here? Preventative actions must be taken at the correct time if they are to be effective. For this reason, once the pest is correctly identified, monitoring must begin before it becomes a problem. For example, in school cafeterias where roaches may be expected to appear, sticky traps are set out before school starts. Traps are checked at regular intervals so populations can be monitored and controlled before they get out of hand. Some factors to consider and monitor
include: Is the pest present/absent? What is the distribution - all over or only in certain spots? Is the pest population increasing, decreasing or remaining constant? This is done through crop scouting. Monitoring might also include the status of the water source being used for irrigation, which could potentially contaminate an area with water borne diseases or spread pests.

4. Establish action threshold (economic, health or aesthetic) - How many are too many? In some cases, there are a standardized number of pests that can be tolerated. Soybeans are quite tolerant of defoliation, so if there are a few caterpillars in the field and their population is not increasing dramatically, there is not necessarily any action necessary. Conversely, there is a point at which action must be taken to control cost. For the farmer, that point is the one at which the cost of damage by the pest is more than the cost of control. This is an economic
threshold. Tolerance of pests varies also by whether or not they are a health hazard (low tolerance) or merely a cosmetic damage (high tolerance in a non-commercial situation).Different sites may also have varying requirements based on specific areas. White clover may be perfectly acceptable on the sides of a tee box on a golf course, but unacceptable in the fairway where it could cause confusion in the field of play.

5. Use resources to keep up to date on IPM developments- Researchers are always discovering new techniques, and ways to improve old techniques. Keeping up to date gives you the best options available to when using IPM.

6. Choose an appropriate combination of management tactics- For any pest situation, there will be several options to consider. Options include, mechanical or physical control, cultural controls, biological controls and chemical controls. Mechanical or physical controls include picking pests off plants, or using netting or other material to exclude pests such as birds from grapes or rodents from structures. Cultural controls include: keeping an area free of conducive conditions by removing or storing waste properly, removing diseased areas of plants properly, late water floods, sanding, and the use of disease-resistant varieties. Biological controls are numerous.

Benefits of Integrated Pest Management
Adoption of Integrated Pest Management (IPM) strategies benefit economically due to sustained development, increased productivity and reduced pest damage. The options that IPM can offer make sole reliance upon synthetic pesticides a thing of the past. In the long-term, everyone benefits through a healthier environment.

Some of the benefits of an integrated approach are as follows:

1. To Agricultural Producers:
Reduction in producer's economic risk by the promotion of low-cost and carefully targeted pest management practices. Proactive avoidance of future pest management crisis; through research directed at potential short-, medium-, and long-term challenges. Reduction of health risk to agricultural workers by fostering best management practice adoption. Among those new systems, integrated arable farming system is characterised by reduced tillage and low fertilizer and biocide application rate (Vereijken and Viaux, 1990) compared with conventional agriculture.

2. To the Environment:
Reduction of environmental risk associated with pest management by encouraging the adoption of more ecologically benign control tactics. Protection of at-risk ecosystems and non-target species through reduced impact of pest management activities. Promotion of sustainable bio-based pest management alternatives.

3. To Pest Management Professionals & Organizations:
Augmentation of private research development efforts to develop lower-risk pest control tactics and expand the use of existing low-risk tactics to specialty markets. Promotion of innovative practices that improve pest management effectiveness, which can increase customer satisfaction and reduce the risk of customer complaints. Creation of a demand for new, innovative, and marketable products and services.

4. To the General Public:
Reduction of risk to the public by promoting responsible pest management in public spaces including schools, recreational facilities, and playgrounds. Promotion of lower-risk residential and community pest control through educational programs tailored to homeowners. Assurance of safe, reliable, low-cost pest control through improved pest management.

IPM holds greater advantage under present conditions when the geometric increase in the world's human population demand greater production of food crops and insect pests continue to put obstacles in the maximization of food production.IPM is valid under diverse production techniques ranging from subsistence cultivation to highly mechanised monoculture cultivation. Further the objective of IPM is to optimise and not maximise pest control, in terms of overall economics , social and environmental values. Integrated Pest Management (IPM) is an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices. IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment. This information, in combination with available pest control methods, is used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment. The IPM approach can be applied to both agricultural and nonagricultural settings, such as the home, garden, and workplace. IPM takes advantage of all appropriate pest management options including, but not limited to, the judicious use of pesticides. In contrast, organic food production applies many of the same concepts as IPM but limits the use of pesticides to those that are produced from natural sources, as opposed to synthetic chemicals.

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