What Tree species are susceptible to the Bark Beetle?
Western Pine beetles attack Ponderosa and Coulter pine and have the most aggressive response to drought because of their ability to reproduce several times per year. Large populations growing in stressed trees can then attack even healthy trees and overwhelm them. Jeffrey Pine beetle attacks Jeffrey pine and does not reproduce as fast as Western Pine beetle. It is present and effective in killing Jeffrey pine but not as epidemic as Western Pine Beetle. Other insects such as Fir engraver and Ips beetles take advantage of stressed trees and can cause mortality as well. Drought causes stress in trees and other agents such as root diseases can also come in and make it appear as if trees are dying of thirst when they are actually being attacked by other causes.
