The Role of Pesticides in IPM

Pesticides are chemicals that are used to destroy, repel, or otherwise lower pest infestations to protect crops from damage. Insecticides are pesticides used to control insects, herbicides are pesticides used to control weeds, fungicides are pesticides used to control fungi and nematicides are pesticides used to control nematodes.

Though pesticides pose many potential risks, they also provide the following important advantages and benefits:
1. Pesticides are readily available and easy to use.
2. Where resistance is not a problem, pesticides are generally highly effective for controlling pests.
3. Pesticide treatments can be rapidly implemented as needed with minimal lag time.
4. Pesticides can be used over large areas to control large populations of pests.
5. Pesticide treatments are often cost effective, especially if the alternatives require large increases in human labor.
6. No effective, reliable, non-chemical alternatives are available for many pests and chemical pesticides are the last resort.

Pesticides are used in IPM programs when no effective alternatives are available or alternatives are not sufficient to keep pest populations from reaching damaging levels. The emphasis is to maximize the benefits and advantages that pesticides offer while minimizing any potential risks.
Whenever a pesticide treatment is needed, selection of the chemical should be consistent with the pesticide label and all state and federal laws and regulations. Additional considerations include: effectiveness against the target organism, compatibility with the host plant, effects on
beneficial organisms, degree of environmental and user safety, and cost. Wherever possible, use a material that is least toxic to humans and other non-target organisms, and is least likely to contaminate ground and surface waters.

Why Minimize Pesticide Use?
Several problems and limitations have become apparent by relying solely on pesticides to control pests. Some of the problems include: pest resistance to pesticides; increased costs; toxicity to fish, wildlife, beneficial natural enemies of pests, and other non-target organisms; concerns about human health and safety; ground water contamination; and overall environmental quality.

Problems With Overuse of Pesticides
Pesticide Resistance:
In an attempt to achieve better or total pest control, resistance problems have increased because pesticides are applied more frequently and at higher dosage rates. These tactics have resulted in increased selection pressure. Naturally resistant individuals in a pest population are able to survive pesticide treatments. The survivors breed and pass on the resistance trait to their offspring. With each passing generation, the pest population becomes more difficult to control
with the same pesticides as compared with earlier generations. Reducing pesticide use and alternating among classes of pesticides with different modes of action can help to lessen the possibility of pest resistance. Managing pest resistance is very important in helping to prolong the effective life of needed pesticides.

Toxicity to Natural Enemies and Other Non-target Organisms:
Natural enemies of pest species can be very helpful in keeping pest populations at lower levels. These beneficial organisms include organisms that are predators, parasites, or competitors to the detriment of the pest species. For example, aphids do not reach pest levels every year because many different natural enemies help to keep them in check. Unfortunately, many broad-spectrum, non-selective pesticides are more detrimental to numerous beneficial species than to the pests. The use of such pesticides often causes a resurgence in pest populations and at a much faster rate compared to the natural enemies. Without the natural controls, primary (established) and secondary (new) pests are often free to reach damaging levels at faster rates. An increase in pest levels usually results in additional pesticide treatments, which further depresses or eliminates the natural enemies and further encourages the potential for pest resistance. Selecting effective alternatives that are less toxic to non-target organisms, will increase natural enemy survival, and overall effectiveness of pest control.

Public Health and Environmental Concerns:
The public has become increasingly concerned about the use of pesticides and the possible adverse effects on human health, wildlife, ground water, and overall environmental quality. Pesticide exposure from drift to non-target areas; contamination of ground and surface waters; and residues on food are topics of concern to the general public. Applicators should be especially concerned because they may have the highest potential for exposure and thus, may
have the greatest health risks. All applicators must be sensitive to public concerns about pesticide use and apply materials only in a safe and judicious manner

Cost of Pesticides:
The cost of developing new pesticides has risen at an increasingly rapid rate. Government regulations and more stringent registration requirements have also slowed the rate of development and increased the costs of new products. Concerns about potential product liability have discouraged companies from introducing new products. Increasing problems with pest resistance have likewise resulted in shorter market lives for many pesticides than in the past. All of these factors result in higher costs and potentially lower profits for chemical companies. In turn, this leads to higher prices for pesticide users. Maintaining the economic viability of agriculture is also one of the goals of Integrated Pest Management.

Reduced Risk Pesticides
EPA has established a category of pesticides called “Reduced Risk” pesticides to encourage the development, registration and use of products which could result in reduced risks to human health and the environment. New conventional pesticides are considered for “Reduced Risk” status if they have at least one or more of the following characteristics: low risk to human health, low toxicity to non-target organisms, low potential to contaminate ground water, surface water or other valued environmental resources and have the potential to expand the adoption and effectiveness of IPM.