Pest Identification

The first, and most critical, step in any pest management program is to identify the pest correctly so that you can be sure that a problem is related to pest damage and not to some other cause. Pest control failure is most often caused by incorrect pest identification resulting in the lack of accurate information about a pest.

For example, plants may be damaged by non-living agents such as weather extremes, air pollutants, road salt, and inadequate or excessive fertilization but this damage can be easily mistaken for that caused by living pests.  In addition, it’s easy to be fooled into thinking that an organism present at the time the damage is discovered is the cause when, in fact, the responsible organism is something else. For example, sometimes turkeys have been blamed for crop damage because gaggles have been seen in the affected fields during daylight. However, upon closer inspection, the majority of the crop damage was caused during the night by the “true” pests: woodchucks, deer, and/or raccoons. 

A pest species may have different physical forms depending on the stage in its life cycle or the time of year. For example, a weed seedling often looks different from the mature plant. Many insect species undergo significant changes in appearance as they go through their life cycle from eggs to immature stages and finally to the adult form. Management tactics are most effective when timed with treating the most susceptible stage of the pest’s life cycle–correct identification is key.

A hand lens (10x magnification) or microscope may be needed to identify tiny pests such as small insects or mites. When a pest is hidden or not visible, as in the case of some plant diseases, you may need to analyze the symptoms or type of damage to determine the underlying cause. Often the pest’s host (the animal or plant on which an organism lives) is important to making positive identification. Staff with Cooperative Extension will help you identify pests or suggest the cause of a problem. There are some good resources online to aid with some identification, such as and iNaturalist, or Apps such as Seek. Be careful with other online sources as many will provide incorrect identification; a best practice for online resources is to use two to three sources to confirm the identification. It is best to work with an expert and to attend educational webinars and workshops to learn how to properly identify pests.

Once you have identified a pest, you can learn about its life cycle and behavior, the factors that favor its development, and procedures for its prevention or control. Proper identification facilitates the use of more targeted control methods that manage the pest while avoiding injury to beneficial organisms.

  1. What is IPM?
  2. Why Practice IPM?
  3. Pest Identification
  4. IPM Tactics
  5. The PAMS Approach
  6. Monitoring
    1. Insect monitoring traps
    2. Digital monitoring and decision tools
  7. IPM Resources
  8. IPM Quiz