Title: Principles of IPM: Methods of Control

Learning Objective: To understand the various methods of pest control utilized in an IPM program.

Materials: Presentation board (chalk board or flip chart) or slide projector, chalk or pen and lesson hand out.

Time Needed: 3 hours

Power Point Presentation: Lesson 5 (computer file: lesson5.ppt)

Opening: In the beginning of our discussion of Integrated Pest Management, we defined it as "the use of many pest control methods in a well organized and harmonious way in order to achieve long-term pest control". We have learned everything about this definition except it’s essential ingredient, the use of many pest control methods. In this section we will learn about the variety of pest control methods in the quiver of the IPM practitioner as they control pests.


Methods of Control

A. Criteria for selecting a treatment strategy

A treatment strategy should be selected which is:

- most likely to produce an economic reduction of the pest population.

- least disruptive of natural controls.

- least hazardous to human health.

- least toxic to non-target organisms

- least damaging to the general environment.

- easiest to carry out effectively.

- most cost effective over both the short and long terms.

B. Methods of control

1. Cultural Controls

a. Definition: Manipulation of cultural practices to the disadvantage of the


b. Methods

i. Soils and Nutrition: plants with adequate nutrition can grow more

vigorously, allowing them to better tolerate pest damage or to compete

better with weeds. Soil cultivation can also kill some pests

ii. Water Management:

- Too Little Water: poor plant growth, less vigorous plants, and

more susceptible to pest injury

- Too Much Water: can contribute to development of many


iii. Sanitation:

- Removal of rubbish, infested or decaying matter as well as crop

residues from around and in fields can often eliminate breeding

sites for pests

- Using seeds and planting materials which are free of weed seeds

and diseases

- Cleaning equipment before moving from infested areas

iiii. Crop Rotation:

- works on a limited number of pests, by replacing the host plant

with another crop for a period of time, allowing the pest

population to be reduced due to lack of a host. For this strategy

to work:

* The source of the pest must be within the field

* The pest can not be highly mobile

* The host range of the pest can not be wide

* The pest must not be able to survive in the soil for a long

period of time

iiiiii. Multiple cropping/Mixed Cropping:

- Increases the habitat for pest predators

- Limits the number of food plants for specific pests

iiiiiii Trap Cropping:

- Crops planted to attract pests away from the main crop

iiiiiiii. Soil Solarization:

- Uses a plastic tarp to cover the soil. This tarp heats up the soil

moisture to levels which are lethal to many fungi, nematodes,

weeds, weed seeds and other pest organisms

c. Advantages of cultural control methods

- Low cost (in most cases)

- Effects on non-target organisms low

- No Toxicity or residue problems

d. Disadvantages of cultural control methods

- Not always applicable

- May not be sufficiently effective

- Usually preventive in nature, so it requires planning

-May interfere with normal cultural operations

2. Plant Resistance

a. Definition: The use of species or varieties of plants that can grow and

produce despite the presence of the pest.

b. Methods

i. Use of crop varieties which resist pest attack or damage

ii. Resistant varieties may inhibit pest attack through toxic or repellent

compounds or through physical factors such as color or toughness

iii. Resistant varieties may have a high tolerance to pest damage

c. Advantages of plant resistance

- No harmful effects on natural enemies of pests or other non-target


- No toxicity or residue problems

- Can be a permanent solution

d. Disadvantages of plant resistance

- Pest resistant varieties or species of cultivated plants not available for all


- Level of control may not be sufficient

- Discovery and development is slow

- Resistant varieties may not be agronomically acceptable

- Always preventative in nature and thus require forward planning

3. Biological Control

a. Definition: The use of predators, parasites, pathogens and competitors

to control pests.


b. Types

i. Conservation of a naturally occurring enemies of pests. Not

performing practices, such as use of a broad spectrum insecticide,

which could damage the naturally occurring biological control

organism. Also providing a favorable site for the development of a

biological control organism.

ii. Classical biological control: Introduction of a biological control

organism. Examples of this include introducing a predator of an insect pest or planting a cover crop or living mulch to compete with weeds

Augmentation: Applying the natural enemies of a pest as a biological


c. Advantages of biological control

- Low cost

- Has the potential to be permanent

- Not harmful to non-target organisms

- No toxicity or residue problems

d. Disadvantages of biological control

- Not always applicable

- Level of control may not be sufficient

- Research costs are high and may not produce results

4. Chemical Control

a. Definition: The use of toxic substances or pesticides to kill or repel


b. Methods:

i. The decision to use a pesticide should be based upon:

- information obtained from monitoring/scouting

- knowledge of thresholds

- an awareness of potential benefits and risks associated with a


ii. Once a decision to use a pesticide has been made, several questions

should be thought through carefully:

- Is the pest you want to control listed on the pesticide label?

- Does the label state that it controls the pest or does it suppress the


- Are you familiar with the relevant university research and


- Is the recommended rate of application economical for your


- How toxic is the pesticide? dermally? orally?

- Is the pesticide a restricted use product?

- Does the pesticide have the potential to contaminate ground

water, even when label recommendations are followed?

- Will the use of this pesticide expose humans to health or safety


- Will use of this pesticide threaten wildlife populations?

c. Advantages of chemical control

i. Applicable to most pests

ii. Curative in effect

iii. Grower may apply when and where required

iiii. Enable high levels of control of most pests to be achieved, so

unblemished produce can be produced


d. Disadvantages of chemical control

i. May harm natural enemies and other non-target


ii. Resistance to the pesticide can develop

iii. Often toxic to users and may present residue problems

iiii. Costs are high and recurring as control is not permanent


Discuss Hawaii examples of each type of control and field trips to sites which are unitizing these control methods


Agricultural Plant Pest Control, Chapter One: IPM on University of Nebraska Web site: http://ianrwww.unl.edu/ianr/pat/training.htm

Fenemore, P.G. 1982. Plant Pests and Their Control. Butterworths, Wellington, New Zealand. 271 pp.

Flint, M.L. 1990. Pests of the Garden and Small Farm. University of California Pub. # 3332. 276 pp.

Metcalf, R.L. and W. Luckmann. 1975. Introduction to Insect Pest Management. John Wiley & Sons, New York, NY. 587 pp.

Olkowski, W., S. Daar, and H. Olkowski. 1991. Common-Sense Pest Control. Taunton Press, Newtown, CT. 715 pp.

Watson, T.F., L. Moore, and G. W. Ware. 1976. Practical Insect Pest Management. W. H. Freeman and Co., San Fransisco. 196 pp.