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Oak Pests - A Guide to Major Insects, Diseases, Air Pollution and Chemical Injury
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The oaks (Quercus spp.) are among our most valuable hardwood resources, amounting to one-third of the hardwood sawtimber volume in the United States. Over half the annual cut of oak lumber is produced in the 13 Southern States. Oaks are best known for their timber production and resulting fine furniture, beautiful flooring, and other products. Yet, aesthetics, watershed management, recreation, and wildlife are goals now given equal or greater priority by many. The oaks are valued for shade and ornamental purposes -- a single tree sometimes adds thousands of dollars to real estate values.

Insects, diseases, and other environmental influences present a continuing threat to oaks. A major portion of the acorn crop is destroyed during some years - hampering regeneration efforts. Significant mortality and dieback occur sporadically. Terminal and top injury adversely affect tree form. Repeated defoliations cause growth loss and mortality. Borers and decay cause defect and degrade amounting to an annual loss of millions of dollars. Indirect losses occur through disruption of sustained forestry practices, regulation of forest types, and altered wildlife habitat. Homeowners may incur the expense of chemical control and possibly the cost of tree removal if mortality occurs. Nuisances created by numerous insects decrease tourist use and revenue.

It is far better to prevent attack by insects and diseases than to try to fix the damage done.

  • Use cultural practices that maintain and promote tree vigor
    • Match tree species with the planting site
    • Assure adequate water, nutrients, space and sunlight
    • Avoid accidental injury such as bark cuts and limb breakage
  • Use practices that favor natural control
    • Favor birds or other predators which minimize pest populations
    • Use 'pick up and discard' or 'prune and destroy' to eliminate hibernating insects or inoculum reservoirs
  • If the situation warrants, use chemical control measures.

This booklet will help nurserymen, forest woodland managers, pest control operators, and homeowners to identify and control pest problems on oaks. The major insect and disease pests of oaks in the South are emphasized. Descriptions and illustrations of the pests and their damage are provided to aid in identification. Brief notes are given on biology and control to aid in predicting damage and making control decisions.

Chemical controls are subject to change as certain pesticides are removed from the market and new ones are approved for use. The chemical control section (which was part of the original text) has been removed from this version of Oak Pests. Should it appear that chemical control will be necessary to suppress the activity of a pest, contact your state forestry organization, your county extension agent, or the nearest office of State and Private Forestry, Digital Arborist. Help may also be found on the internet. State foresters can be located at the National Association of State Foresters home page:

The Southern states extension agents can be located through the southern Regional Pesticide Coordinators listing at:

One additional site will allow you to contact your state pesticide applicator trainer and locate training sessions which will help in understanding pesticides and their safe and proper use:

In addition to removing the pesticide recommendations (although not the precautions page) a more complete, new, hyperlinked index, a thorough edit, and a complete reformatting have been incorporated to allow this version to take advantage of the inherent power of the web.

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