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ENTOMOLOGY AND PEST MANAGEMENT |
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KEY CONCEPTS
II. Insect Pests of Houses, Pets and Humans
III. Pest Management
IV. Submitting Insects for Identification
V. Orders of Insects and Their Feeding Parts
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PEST MANAGEMENT
There have been and are many approaches to managing pests in crops, gardens, yards and homes. These range from applying no control measures to applying pesticides on a regular schedule. Some people will not use pesticides; others want to get rid of the pest by any means. As a Master Gardener, you must learn all the methods and materials which can be used to manage pests.
When we try to understand all the methods of managing pests and select the best methods for a particular situation, we are using Integrated Pest Management (IPM).
INTEGRATED PEST MANAGEMENT (IPM)
Integrated Pest Management or IPM provides us with a systematic approach to pest control. It begins with using the best gardening practices. Following the correct selection and culture of plants reduces the potential for pests and diseases.
When problems do arise, the next step in an IPM program is determining when a pest is causing enough damage to warrant control. It also helps the gardener determine which of the many possible controls is most effective and appropriate in a particular situation. IPM can be applied to all pest groups: insects, mites, weeds, plant diseases and animals.
Cultural practices are ways the gardener has of changing environmental factors that affect the plants and their pest populations. Cultural practices include irrigation, crop rotation, garden sanitation, soil aeration, mulching, tilling and use of disease- and pest-resistant plants. It is critical that gardeners know the cultural or growing requirements of each plant.
Providing the correct growing conditions results in a vigorous plant that is less likely to be attacked by pests and diseases. Vigorous plants also can tolerate some damage.
The question of when an organism becomes a pest is central to IPM. Deciding how much damage is acceptable with a particular plant or crop is called "establishing a threshold."
Several factors influence how each gardener will arrive at a pest threshold. These factors include the following:
- amount of damage that can be tolerated
- pest population size required to cause significant damage
- the plants' stage of development
- the vigor of the threatened plant(s)
- the life cycle and habits of the pest
The amount of damage that can be tolerated varies with the crop and personal preferences. A few holes on a collard leaf does not require control. However, if most of the leaf has been eaten, the crop is destroyed.
Less than 12 white grubs in a square foot of turfgrass can be tolerated as long as the lawn is growing vigorously. However, if the density of grubs rises above 12 per square foot, damage will be significant.
Colorado potato beetles will devastate a potato crop early in the season. Late in the season the beetles can ea t all of the foliage and there is little damage to the crop.
Peach tree borers are extremely difficult to control once they bore into the trunk of the tree. Knowing that the adults lay eggs in mid-July to mid-August and that the young larvae are susceptible during this period, permits the gardener to effectively apply controls.
Establishing thresholds in the garden involves observing the plant and its total environment.
There is also the question: Does the cure cause more damage than the pest? There is a risk involved in using the more toxic pesticides. This risk must be weighed against the potential benefit.
You must monitor the garden to determine when action is necessary. Thoroughly inspect the plant: the underside of leaves, buds, new growth, even the roots in extreme cases.
Regular inspection allows the gardener to identify a problem before major damage occurs to the plant. Controls will be more effective if the problem is caught early. Infrequent inspection results in extensive damage. Once extensive damage occurs, it is often too late to do anything.
Inspect the plant's entire environment for clues to the problem. Too much or too little moisture, wind, humidity and light may cause stress that results in susceptibility to damage from pests and diseases. Observing and keeping records of weather conditions provide clues to growth patterns and problems.
Certain insect pests can be monitored by using traps. Colored, sticky traps, PHEROMONE traps, pitfall traps and light traps are used with some pests. Whiteflies and aphids are attracted to bright yellow, sticky cards and are trapped on the sticky surface.
IDENTIFY THE CAUSE OF THE PROBLEM
The problem may be caused by insects or related pests, diseases or cultural practices. Often, the problem is caused by a combination of these factors. Identify the pest or disease and the conditions that allowed that organism to become a problem.
Reference materials will guide you to common problems for a particular plant. Most guides are organized by plant. They list the insects and diseases that attack each plant. The ORTHO PROBLEM SOLVER is an excellent resource for identification. A questioning attitude and close inspection are required to make an accurate diagnosis. A magnifying or hand lens is helpful.
Closely examine the specimen for feeding or disease patterns. If insects are involved, try to collect the pest. Identification of insects and diseases is available through local Extension offices and the Plant and Pest Diagnostic Clinic at The Ohio State University.
To prescribe a control, you must understand the pest organism, its life cycle and the type of damage it causes. Consider all control options. Select the most effective and appropriate option or combination of options.
Apply controls at the right time. Insects are more vulnerable at certain stages of their life cycle. Eggs may be controlled with oil sprays. Larval stages are particularly vulnerable. It is critical to control insects before they reproduce and increase their population. When an insect is protected by the pupal case, control is nearly impossible.
Reapplication may be necessary for many pests to kill the young as they emerge from eggs. Know how long the pesticide remains effective on the plant. This is also important in food crops. You must observe the prescribed time lapse between the last application and harvest.
You may want to apply a pesticide and then enclose the plants in netting to keep further infestation from occurring. Or, you may decide to put up netting and then release predators.
Diseases are more difficult to control. Most of the fungicides prevent infection or at best stop an infection from spreading.
Apply controls as instructed. Netting is not effective if there are unprotected areas. Pesticides must be applied to both the top and underside of leaves. Surfactants or spreader/stickers help the pesticide adhere to and spread over the foliage surface. Application rates are critical. The proper dilution is required to kill the pest. If too concentrated, plant damage may occur.
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