October 2, 2013 (Updated August 20, 2019, September 11, 2019, October 2, 2019, June 2020)

While EAB was first confirmed in Boulder in September of 2013, its presence has been confirmed in the City and County of Broomfield, in the City of Westminster (Adams County) in Larimer County near Berthoud, and most recently in the City of Arvada.  This insect has devastated ash trees in many midwestern and eastern states. Please review the Colorado Department of Agriculture’s website for additional information. This pest infests only ash trees. Mountain ash are not ash trees; they belong to a different family of plants and do not develop infestations. Additional information will be posted as it becomes available.