Forest Pest Control
Douce, G.K., Moorhead, D.J., and Bargeron, C.T., Forest Pest Control, The University of Georgia, College of Agricultural and Environmental Sciences, Special Bulletin 16, Revised January 2002.
Principles of Forest Pest Management
Interest in protecting forests from insect, disease, weed and vertebrate pests has increased in recent years. This has come about largely because of:
Forest managers have come to realize that much of the damage caused by pests could have been avoided. With adequate knowledge of pest identification and biology, combined with good forestry management practices, it may be possible to prevent or at least reduce losses due to pests. Trees in a vigorous condition are much better able to withstand damage by pests than trees already under stress.
We have learned that using a combination of prevention and control methods is the best approach to pest problems. The planned strategy of combining the best methods is called Integrated Pest Management (IPM) and is discussed in the “Applying Pesticides Correctly” core manual. Pest management should be a part of an overall forest management plan. The need for pest control treatments can often be minimized through wise, long-term forestry practices. The pest control method(s) chosen will depend upon the kind and amount of control necessary, balanced with costs and benefits within legal, environmental and other constraints. The most important principle of pest control is to use a control method only when necessary to prevent unacceptable levels of damage. Even though a pest is present, it may not be necessary to control it. It may cost more to control the pest than to cover damage or losses.
Before making management decisions, managers should evaluate potential pest impacts within the context of the ecosystem in which the organism occurs, as well as the population dynamics of the organism. Will the impact of an organism increase, decrease or maintain its level of damage over time? What part(s) of the tree does the pest affect? How many trees are or will potentially be affected? What will be the longterm impact of these organisms? Does the organism cause permanent or only temporary damage? Insects such as the southern pine beetle damage the cambium layer and introduce fungi that almost always cause tree death. In contrast, many foliage feeding insects cause one-time defoliation from which the tree can recover. Most trees can withstand complete one-time defoliation without significant longterm impact on tree health. However, an organism that has the potential to cause multiple defoliations (such as the gypsy moth) can have a much more detrimental impact on tree and forest health.
Before choosing a control method(s):
If other management options do not yield satisfactory results, you may need to apply a pesticide to control an undesirable organism (pest) in the environment. The challenge is to use pesticides in a manner that will cause the least harm to non-target organisms in forests, seed orchards and nurseries, while achieving the desired management goal.
Pesticides are tested and labeled for specific pests, crops and for land-use situations. Use of insecticides, fungicides and herbicides is common in managed seed orchards, forest nurseries, intensive short-rotation plantations, and in Christmas tree production. In general, the most commonly used forest pesticides are herbicides used for site preparation, herbaceous weed control, and in pine release treatments. Insecticides are seldom used in general forest management because of high treatment costs and because some pest insects are highly mobile. Currently, the only disease control treatment common in general forestry field applications is for annosus root rot. Vertebrate animals are sometimes controlled through trapping or hunting, but repellents and poison baits may be employed.
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Last updated on Thursday, May 02, 2002 at 01:04 PM
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