Tiny Beetle Threatens Colorado's Ash Trees

The emerald ash borer, a destructive wood-boring beetle native to Asia, is advancing south along Colorado's Front Range. Since its first detection in Colorado in 2013, the insect has spread to at least 29 communities. This year, confirmed findings include Firestone, Ken Caryl, Parker, and Colorado Springs, marking the first confirmation in Douglas County.

Arborists have identified typical signs of infestation, such as thinning branches, deadwood, and distinctive D-shaped exit holes. The beetle's larvae tunnel into the tree, severing the flow of water and nutrients, which experts state leads to a 100% mortality rate in affected trees if untreated. Colorado's ongoing drought may exacerbate the problem by stressing trees, making them more susceptible.

Preventative measures include injecting tree trunks with insecticide, such as emamectin benzoate, which costs approximately $200 every two years. This treatment protects trees by killing the borers before they can lay eggs. However, for trees already in serious decline, removal is strongly recommended to prevent further spread and multiplication of the beetles.