Managing Pests

Is your pest management program effective and environmentally safe?

Pests have altered the course of human history by attacking crops and domesticated animals and by transmitting human diseases. Farmers have used many different methods, from hand-hoeing to using pesticides, to combat pests. Over-dependence upon pesticides have lead to problems such as pest resistance, destruction of helpful insects, and contamination of water resources. Integrated pest management (IPM) has emerged over the last 30 years as a way to organize pest control activities. IPM uses pratical, proven methods of pest control to help producers control costs and increase profits. IPM is not restricted to crops. Livestock and poultry IPM programs have successfully aided producers to reduce losses due to parasites.

IPM combines proven pest control methods, such as crop rotation and resistant varieties, with new activities, such as pest monitoring and using pesticides only when economically justified. IPM is based upon the fact that eliminating all pests from production systems is impractical. But how many pests should you allow before taking action? IPM provides the decision-making tools needed to make this decision.

How can we help?

This publication has been prepared to help farmers evaluate their pest
management practices and figure out how to implement an effective pest management program. By reading each section and answering a series of questions, you will be able to determine how to improve pest management on your farm. Each section deals with a different topic. The questions are designed to help you evaluate your practices within that topic.

• If you answer a or b, you are doing well in this area.
• If you answer c or d, you could improve your practices.

If you would like further help in managing pests on your farm, please visit your nearest Cooperative Extension Service Center, your local Natural Resources Conservation Service office, or your North Carolina Soil and Water Conservation District office.

IPM Skills

1. Can you identify major pests by sight and do you understand their life cycles?

Most pest remedies are pest specific. Just knowing that you have "bugs" or "weeds and grasses" is not enough to develop effective control measures. While being an identification expert on every possible crop pest is not practical, being able to identify major pests by sight and being familiar with their life cycles is possible. Major pests are the ones that occur annually and often require remedial treatment. Being able to identify major pests quickly and correctly allows you more time to obtain and consider advice on the best control tactic should the pest reach treatable levels.

All pests are occupied with gathering resources to live and reproduce. Good pest management programs seek to deny life-sustaining elements to pests. A working knowledge of how natural forces (weather and natural enemies) and cropping systems (fertilizers, tillage practices, and varieties) affect pests provides the basis for developing pest management tactics. The importance of having a working knowledge of how pests live cannot be overemphasized.

1. Circle the answer that best describes how well you can identify major insect, weed, nematode, and disease problems.

a. I can recognize almost all annual pest species by sight and have a complete identification library in case I need help.

b. I can identify most major pests by sight and have some pest identification materials.

c. I recognize some major pests with difficulty and have few identification aids available.

d. I depend upon Extension agents, neighbors, or agribusiness personnel to identify pests.

2. Do you participate in training programs on pest identification?

If you do not feel confident of your ability to identify pests or of your knowledge of how those pests live, ask your local Cooperative Extension agent for assistance. Training courses and identification guides will help. Many free publications and identification guides are available through the North Carolina Cooperative Extension Service (see list of publications at the end of this fact sheet).

2. Circle the answer that best describes how often you attend meetings that present information on pest identification.

a. I regularly attend pest management meetings and obtain written materials on pest identification.

b. I often attend pest management meetings to learn more about pest identification.

c. I sometimes attend meetings to learn more about pest identification.

d. I rarely attend meetings about pest identification.

3. Do you know how to properly handle and ship a pest sample?

You can get assistance identifying pests from the plant and insect clinic at NC State University and the N.C. Department of Agriculture and Consumer Services. Proper handling and shipping of a sample is important. Contact your county Cooperative Extension Center for more information on pest collection, handling, and shipping.

3. Circle the answer that best describes how well I know how to properly collect, handle, and submit a pest sample for identification.

a. I am completely familiar with procedures for taking, handling, storing, and submitting pest or plant samples.

b. I am generally familiar with procedures for taking, handling, and submitting pest and plant samples.

c. I have at times submit samples and am generally familiar with the procedure.

d. I rarely submit samples and have to be reminded of the process.

4. Do you know how to select and use pesticides safely and effectively?

At one time, farmers selected pesticides based solely on how well they worked and their cost. Now, however, you also must evaluate potential human health and environmental factors. Useful pesticides have been canceled and more will be canceled in the future due to these concerns. It is important that the valuable tools remaining be used as responsibly as possible. It is important to prevent health effects on workers who load, mix, and apply pesticides. Farmers also need to consider environmental factors like the slope of the field, soil type, irrigation, water table depth, distance to surface water, time of year of application, and wind speed. Sprayer calibration information is available at all Cooperative Extension Centers.

4. Circle the answer that best describes how much weight
you give factors like the potential for leaching, slope of the field, method of application, and human health concerns when selecting pesticides.

a. I weigh many factors when selecting pesticides.

b. I consider some factors other than cost and efficacy.

c. I evaluate some environmental factors (such as drift) and human health concerns, but cost and effectiveness are most important.

d. I only consider a pesticide's cost and whether it will kill a particular pest.

5. Do you rotate pesticide classes to reduce pest resistance?

Every time a pesticide is used it can cause a change in the genetic makeup of the target pest population. Individual pests that are not killed by the pesticide reproduce, giving rise to more resistant pests. Over time, these resistant individuals represent a larger and larger proportion of the population, and pesticides no longer afford effective control. This is a natural process that can be countered by rotating chemical classes. Different classes of pesticides differ in the way they kill pests. Changing classes of pesticides keeps pests from adapting—becoming resistant—to any one chemical. It is important to be aware that pesticides with different names are not necessarily from different chemical classes. Contact your local Cooperative Extension Service Center for help in determining chemical classes for common pesticides.

5. Circle the answer that best describes how much you consider the potential for pest resistance when selecting pesticides.

a. I always rotate classes of pesticides.

b. I generally rotate classes of pesticides, but not if it costs more.

c. I rotate classes of pesticides if there are equal choices.

d. I rarely, if ever, rotate classes of pesticides.

6. Do you consider how particular pesticides may affect beneficial insects when selecting pesticides?

Some insecticides are highly effective, but are also highly toxic to beneficial insects, including honey bees and natural enemies. Use of these products will provide immediate control of pests but will lead to the need for additional treatments because beneficial insects are killed, too. Pest insects will "rebound" to even higher levels than before treatment because they are free of natural controls. This "treadmill" effect—where one pesticide application leads to another—must be avoided because each treatment is less effective than the last and more costly.

This often happens when spider mites are a problem. Some insecticides are very toxic to beneficial mites. The plant-eating mites are then free to reproduce unhindered by predators. Deciding which pesticide is the best fit for each situation requires specific information. For example, is the insecticide more or less toxic to beneficial species? When is the best time of day to spray to control pests yet avoid beneficials? And will it affect other (non-target) insects that the beneficials use for alternate hosts?

6. Circle the answer that best describes how much you consider the effects of insecticides on beneficial insects.

a. I always try to select insecticides that are the least disruptive to beneficial insects.

b. I often consider effects on beneficial insects.

c. I sometimes check on possible effects on beneficials, but cost is more important to me.

d. I do not consider beneficial insects when I select insecticides.

IPM Tools

7. Do you use soil testing to guide your application of fertilizers?

Crops need vigorous growth to compete effectively with weeds and to repair damage caused by insects, but over-fertilization often attracts more insect pests. Lush growth also can encourage plant pathogens. For example, both cotton and tobacco can have higher levels of insect pests for longer periods if they are over-fertilized. Thus, an important balance is needed between healthy crops and insect-prone crops. Fertilizing crops, based on regular soil testing, so that the plants get what they need—but no more—is the best way for growers to maintain a balance.

7. Circle the answer that best describes how you use soil test results in your fertility program.

a. I base my fertility program on regular soil test results (every other year).

b. I have my soil tested every 4 years or more.

c. I base my fertility program on general recommendations from Extension agents or fertilizer suppliers.

d. My fertility program remains unchanged from year to year.

8. Do you consider pest resistance when choosing plant varieties for your farm?

When available as an option, host plant resistance is the cheapest way to prevent or minimize pest damage. Because no pesticides are required, pest control can be achieved without worker or environmental risk. However, resistance does not mean immunity. The level of resistance and the pest species or race to which the plant is resistant must be considered carefully. For example, race-specific resistance to nematodes will control problems caused only by specific races of a nematode species. General resistance will control the damage caused by the entire pest species. So matching resistance to the target species (and race) is important. In addition, rotation of resistant varieties is critical to success. Just like pesticides, resistant varieties can increase the proportion of pests that are immune to the resistance.

8. Circle the answer that best describes how strongly you consider pest resistance when choosing varieties.

a. Pest resistance is a critical part of my variety selection.

b. Pest resistance is as important to me as yield potential when I select varieties.

c. I sometimes consider pest resistance, but yield potential is the most important characteristic that I use in selecting varieties.

d. I do not consider pest resistance as part of my variety selection.

9. Do you use crop cultural control to minimize pest problems?

Crop management is the planned alteration of the environment to favor a crop plant over all others. Almost every aspect of how crops are grown affects pests—from the variety used to the harvest date. Usually crop management decisions are made with one end in mind: to maximize yield. This is understandable. However, growers can make choices that will not negatively affect production—they may, in fact, increase yield—that can have a positive or a negative effect on pests. The deliberate alteration of the crop environment to manage pests is called cultural control. Objectives of this practice include:

• Preventing pest invasion.
• Creating conditions that favor crops and disfavor pests.
• Changing situations so that pest injury causes less crop damage.
• Encouraging natural enemies of pests.

Some of the crop management tools available are:

• Crop rotation.
• Tillage.
• Timing of planting or harvesting.
• Trap crops.
• Sanitation.
• Water management.
• Nutrient management.
• Fertility program.
• Cover crops.

The architecture of a crop (height, plant spacing, row width, etc.) is one of the biggest influences on eventual pest levels. Pests are opportunists that take advantage of resources available in a crop. For example, light penetrating a crop is a resource for weeds. Thus, open canopies and wide rows encourage weeds. Reducing the light that penetrates a crop by only 50 percent will prevent 75 percent of the weeds from germinating and growing. No-till residue, living mulches, early planting, narrower rows, and higher plant populations are all examples of ways to reduce light, thereby reducing weeds. Planting soybeans in narrow rows encourages beneficial insects that can (and often do) prevent pest insects from reaching damaging levels. Planting earlier or later than normal can affect plant pathogens, insects, and weeds. How much pests are affected depends on the crop and pest. Quick destruction of crop residue after harvest denies pests the resources they need to continue reproducing or to prepare for winter. You should use crop cultural practices as a pest control tool.

9. Circle the answer that best describes the role that planting dates, row widths, and plant populations play in your pest management program.

a. I often use planting options to combat pest problems.

b. I sometimes use planting options, but yield is equally important.

c. I consider planting options, but yield potential is most important.

d. Planting options depend entirely on my time and equipment.

10. Are you finding pests and making effective treatment decisions?

Deciding when to use a pesticide to control a pest problem can be difficult. During one growing season, pest abundance can vary from complete absence to economically damaging numbers. It is easy to make a decision at the extremes, but what do you do when pests are present but do not appear to be damaging the crop? The best way to determine whether the pests are likely to cause economic loss is to find and count pests. Looking for pests on a regular basis is called scouting. The advantage of scouting is that potential pest problems are found early, allowing the pest manager time to identify the pest, develop a management strategy, and wait to see if other controls (for example, natural mortality) will suppress the pest. Scouting can include directly measuring pests (insects and weeds) or using weather monitors to make insect and disease forecasts. In any case, developing a means to discover and track potential pest problems is an essential part of IPM.

10. Circle the answer that best describes how often you check your crops for pests.

a. Crop and pest scouting are a integral part of my pest management program.

b. Crops are checked only when I expect pests to be a problem.

c. Crops are checked only when other field activities are going on.

d. Crops are treated regularly, so there is no need to check for pests.

11. How do you use scouting information to decide when to apply pesticides?

Once fields have been scouted for pests, the next questions to answer are: when is it economically justified to apply a pesticide, and when is the best time to apply it? These are vitally important questions because pesticides applied when they are not needed waste money and can contribute to environmental problems. To help farmers with this decision, scientists have developed economic thresholds (ET) as guidelines.

When pests first appear, biological damage to crops is apparent; but it is usually not important, because plants are adapted to withstand some damage without a yield loss. How much biological damage does it take before economic damage results? A few worms or weeds in a field are no cause for alarm. But what about 1,000 or 10,000? At some point there are just too many pests. At that point it pays to initiate remedial control, such as cultivation for weeds or use of a pesticide. That is when thresholds become important. An ET is a predictor of potential economic loss if nothing is done to stop the pest damage. ETs are developed by scientists who spend a great deal of time carefully measuring the relationship between pest damage and yield loss. Once the point of yield loss has been determined, the ET is set at a lower level to ensure that farmers have time to take action before they sustain economic losses.

11. Circle the answer that best describes how you time your pesticide applications.

a. I always use economic thresholds or forecasting systems.

b. I consider economic thresholds or forecasting.

c. I sometimes use economic thresholds or forecasting, but experience is the best indicator of when to treat.

d. I check crops only when other field activities are going on.

12. Do you use natural controls to manage pests?

Beneficial insects provide a huge amount of free pest control if left alone. In pest management, you first should try to conserve beneficial insects because you may be able to reduce or eliminate the need for other control measures. Ideally, if a field has a rich diversity of insect predators and parasitoids (insect parasite), these beneficials can provide a buffer between insect pests and economic loss. In the proper setting, these beneficials can switch between pest species and other food sources as pest populations rise and fall. Crops can generally have a very diverse array of beneficial insects if steps are taken to conserve them.

Consider using these conservation methods:

• Select and use pesticides to minimize direct mortality of natural enemies.
• Preserve an area that is never treated with pesticides; this may be in a crop or non-crop area.
• Preserve plant diversity in the ecosystem to provide beneficial insects with alternate hosts, food, and over-wintering sites.
• Provide alternate hosts. Beneficial insects may not be able to maintain themselves without other crop hosts.

Some growers augment their natural supplies of beneficial insects by releasing them in hopes of preventing pest populations from reaching damaging levels. Growers purchase and release commercially available predators or parasitoids into crops. Normally, large numbers (tens of thousands to hundreds of thousands per acre) of beneficials are used to overwhelm the pest. This may cause the augmentation to be uneconomical. Release of highly mobile insects, e.g. lady beetles, may be ineffective because of the likelihood of dispersion. In some cases, small numbers are released with the expectation that the beneficial will reproduce and eventually control the pest species.

12. Circle the answer that best describes how you use beneficial insects in your insect management plan.

a. I regularly conserve or augment beneficial insects as part of my insect management program.

b. I consider and use conservation of beneficial insects if possible.

c. I know the contributions of beneficial insects, but do not actively use them as a part of my insect management program.

d. I am not aware of beneficial insects and do not depend upon them.

13. Do you map weeds and soilborne diseases?

Late in the growing season, it is important to record the areas infested by weeds and soilborne diseases via pest mapping. Identification is easiest at this time of year. These pests usually occur in the same areas when the same or a similar crop is planted there. Memory is seldom a dependable way to relocate problem areas two to three years later. Mapping pest locations enables you to apply pesticides or other preventive measures to only the areas most likely to have a problem in subsequent years. The use of Global Positioning System tools facilitates highly accurate mapping and precise pesticide applications.

13. Circle the answer that best describes how you record the identity, location, and severity of problem weeds and soilborne diseases.

a. I make yearly maps of all fields and use the maps to develop my pest management plan.

b. I make maps of the fields with the most problems and use them in pest management planning.

c. I sometimes use maps if a field has a particularly severe problem, but mapping is not a routine part of my pest management planning.

d. I do not map fields as part of my pest management plan.

Developing an IPM Plan

14. Do you have an effective pest management plan?

Because IPM incorporates many different pest control tools, it is helpful to have a plan designed specifically for your farm. When making an IPM plan, remember that each action should target a specific pest or group of pests.

A good pest management plan begins with setting goals. How does the current pest situation need to be changed? Is control unsatisfactory? Do you spend too much money on pesticides? Defining specific problems that need to be addressed helps to determine the goals. Setting goals is important as they provide a benchmark for evaluating progress.

Past pest problems are a good predictor of future challenges. Identify pests and assign some measure of frequency (yearly, sporadic, rare) and severity of each pest's damage. Also include the cost of control—when the pest has to be controlled—and the equipment needed for control measures. Use all of these data to make a priority list of pest problems. Then address the most important pest problems (in terms of money, time, and labor) first.

14. Circle the answer that best describes how you start pest management planning.

a. I base my pest management plans on a careful analysis of common pest problems and the results of my control measures used.

b. I base my pest management plans on problems encountered during the previous year.

c. I loosely base my pest management plans on typlical problems encountered.

d. My pest management depends upon pesticides, so no real planning is needed.

15. How do you incorporate off-site concerns into your pest management plan?

You may encounter environmental problems if you apply pesticides near surface water or buildings. Unless there is almost no wind, it is very difficult to make applications without some drift. No wind could be equally problematic because of the development of temperature inversions. You may need to treat some fields differently due to off-site concerns. When making pesticide decisions, use information about the chemical and physical characteristics of potential materials to select the pesticide least likely to cause off-site problems. Chemical suppliers, consultants, and Extension faculty can advise you on the potential for off-site movement.

15. Circle the answer that best describes how you evaluate potential off-site problems with pesticides.

a. Slope, drainage, water tables, and surface water are all included in a field-by-field analysis of pest problems and potential pesticide selections.

b. I am aware of some potential environmental problems that must be considered in pest management planning.

c. I generally assume that if pesticides are used according to the directions on the label, no environmental problems should result.

d. I do not consider potential environmental impacts.

16. Does your plan consider each major pest?

After you make a priority list of pest problems, develop a strategy to manage each pest. Will changes in cultural practices (planting date, row width, variety) provide adequate control? If not, what additional measures will be required? Consultation with knowledgeable people will help you frame a plan. However, plans must be flexible because pest problems vary from year to year.

16. Circle the answer that best describes how you consider each major pest as you develop your management plan.

a. I consider all control measures for each major pest in pest management planning.

b. I consider all control measures, but I lump pests into general categories.

c. I base my pest management plan on control measures used successfully in the past.

d. My pest management plans depend upon pesticides for control.

17. How do you evaluate the effectiveness of your pest management plan?

Once you have made a plan, begin evaluating it. Is the plan effective in accomplishing the goals you set? Be sure to give the plan enough time to work before changing any major component.

17. Circle the answer that best describes how you evaluate the effectiveness of your pest management plan.

a. I evaluate pest management results using previously set goals.

b. I judge pest management based on the amount of economic pest damage and the cost of pest control.

c. My goal is protection of crops with little or no pest damage.

d. I do not evaluate my pest management plan results.

18. Are you ready to adjust your plan if you are not meeting your pest management goals?

If it becomes clear that major goals are not being met, then you may need to adjust the plan. Also, conditions may change, which will, in turn, necessitate changing your pest management goals. However, be wary of making adjustments too soon. Sometimes the benefits of cultural adjustments, for example, can take some time to become apparent.

18. Circle the answer that best describes how you adjust your plans if you find your pest management program is unsatisfactory.

a. I change my plans if my goals are not met or the pest situation changes.

b. I change my plans only if pest damage or the cost of control seems excessive.

c. I change my plans little unless major problems occur.

d. My pest management plans change little from year to year.

19. Are you keeping effective pest management records?

Keeping records is a vital part of pest management. Busy schedules cause memories to fade and important information to be lost if it is not recorded. These records will provide vital information for making and adjusting plans from season to season. You are legally required to maintain records of all restricted-use pesticide applications for two years.

19. Circle the answer that best describes the role record keeping plays in your regular pest management activities.

a. I maintain detailed pest management records on pests.

b. I keep pesticide records, but no pest accounting.

c. I maintain restricted use pesticide records only.

d. I keep few or no records.

Contacts for Further Information

This publication was designed to review general approaches to integrated pest management. For more information about IPM for specific crops, contact field faculty at your local Cooperative Extension Service Center or visit the North Carolina State University IPM website at http://ipmwww.ncsu.edu.

Related Publications

• Cotton Insect Scouting Guide, ENT-COT-6
• Scouting Tobacco in North Carolina, AG-400
• Scouting Peanuts in North Carolina, AG-461
• Scouting Small Grains in North Carolina, AG-521
• Integrated Pest Management Soybean Scouting Manual, AG-385
• Scouting Corn in North Carolina, AG-399
• Biological Control—Purchasing Natural Enemies, AG-570-1
• Biological Control—Application of Natural Enemies, AG-570-2

These publications are available at your county Cooperative Extension Service Center. You also may order these publications from Communication Services, Campus Box 7603, North Carolina State University, Raleigh, NC 27695-7603.

College of Agriculture & Life Sciences . NC State University
School of Agriculture . NC A&T State University

Prepared by

Mike Linker
Integrated Pest Management Coordinator
North Carolina Cooperative Extension Service

Janet Young
Layout and Design Specialist

The concept for these materials was adapted from materials produced by the National Farm*A*Syst Program, University of Wisconsin, Madison, WI.

North Carolina's Farm*A*Syst and Home*A*Syst Program is coordinated by Deanna L. Osmond, North Carolina State University. Technical editing was provided by Judith A. Gale, Southern Sterling, and Wayne Buhler.

This project has been funded with Section 319 grant monies from the U.S. Environmental Protection Agency through the N.C. Department of Environment and Natural Resources, Division of Water Quality.

Published by

NORTH CAROLINA COOPERATIVE EXTENSION SERVICE

Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

AG-566-14
E00-38869

This document was updated on 9/13/00 by Janet Young.