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Action Threshold

If pest populations threaten plant health, become a nuisance or aesthetically intolerable, the action threshold may have been exceeded and suppression tactics should be  implemented by using IPM practices either alone or in combination.

The important thing to remember here is that there is  no such thing as an insect-free landscape. Insects are a vital part of the environment and, overall, play an important beneficial role.  So, just because a pest is present doesn’t necessarily mean there is a problem.

First, consider cultural methods such as removal of a chronically-infested plant and replacing it with a non-host plant species or variety. If natural enemies of the pest are present, preserve them and determine if there are biological control agents available and feasible for release for the problem. Finally, consider use of chemical controls, when justified.  Even then, the least-toxic methods should be given preference.

Questions to Ask Before Making Pest Management Decisions

  • What pests are present, in what numbers and stages of development?
  • What conditions exist that may increase or decrease pest problems?
  • What natural enemies of the pests, such as parasites, predators, and diseases, are present that may play an important role in control?
  • What amount and type of damage is being caused or may soon be caused by pests?
  • What is the stage of development, condition, and value of the landscape and plant materials?
  • What is the potential for economical injury? How much damage is tolerable? Has the action threshold been reached?
  • What pest management options are available, and how do the advantages and disadvantages of each apply to the situation?
  • If alternatives are not available, is a pesticide treatment justified for the situation? If so, what is the material of choice?
  • If a pesticide is not justified, what approaches, if any, should be taken?

Once you’ve made the appropriate pest management decision, do you know what type of pest control is best for your landscape situation?  Find out more about pest control here.