About forest pests

Forest pests and pathogens fall under biotic disturbances, meaning that the source of illness to a tree or a forest is a living organism. For a simple description these living organism have been classified into the following categories and subcategories.

Click on the category name to be brought to a page describing important pest species and diseases that are impacting the forest sector worldwide.

Forest pests:

Are living organism – plants, animals and pathogenic agents - detrimental to the forest health. The most relevant categories under forest pests are described here below:

1. Emerald ash borer Insect pests:

Represent the wider portion of forest pests. (ph.1 courtesy of Debbie Miller, USDA Forest Service, Bugwood.org)

2. Armillaria mellea Forest pathogens:

Are yet represented by living factors not classified as animals such as: bacteria, fungi, algae, etc. and they are responsible to cause forest diseases. (ph.2 courtesy of Dave Powell, USDA Forest Service (retired), Bugwood.org)

3. Pine wilt nematode Other forest pests:

Are represented by non-insect pests such as certain nematodes and other small parasites that can spread diseases among trees being hosted on a number of beetles or other insects. The definition also includes: mites, parasites, mammals, birds, plants, etc.(ph.3 courtesy of Mactode Publications, Mactode Publications, Bugwood.org)


Many of these Forest pest species profiles form a major chapter in the FAO publication Global review of forest pests and diseases.

last updated:  Friday, February 23, 2018