Pinyon and juniper species are hosts to a large number of insects, disease, and fungi. All three can cause reductions in seed crops and increase susceptibility to other pests and mortality. Insects are the largest cause of mortality with bark beetles (Ips spp.) considered the most important insect mortality agent in the Colorado Plateau. Drought is closely linked to pest-outbreaks and can significantly increase mortality, especially in the Colorado Plateau.
For more detailed information and citations refer to: Miller, R.F. and others. 2019. The Ecology, History, Ecohydrology, and Management of Pinyon and Juniper Woodlands in the Great Basin and Northern Colorado Plateau of the Western U.S. US Forest Service, Rocky Mountain Research Station. RMRS-GTR-403. 284 pg.