Insects & Diseases

Non-native species often have a significant impact on newly invaded environments. Due to factors relating to host resistance and a lack of established natural enemies, introduced (non-native) organisms often display a propensity for rapid population growth and expansion. In forest environments, this invasiveness often results in displacement of native species and a high degree of ecosystem disruption.

However, our ecosystems also host a vast variety of pests and pathogens that are native to the continental United States that play valuable roles in the healthy function of the Nation’s forest ecosystems.

On occasion, these native pests, must be periodically addressed by forest managers on a local or regional basis. Examples of such native insects include the Douglas-fir Tussock Moth, eastern and western Spruce Budworm, various wood boring beetles, and several sawflies and scales. Diseases caused by native pathogens include Port-Orford-Cedar Root Disease, Heterobasidion root rot, and several other diseases, cankers, blights, and wood rots. Native insects noted for their damage potential (the Mountain Pine Beetle, the Western Pine Beetle, and the Fir Engraver) are highlighted below. Information on other native forest insects and diseases may be found at the Forest Insect & Disease Leaflets website.

Native disease Pests include:

Native Insect Pests include: