For many Coloradans, the word “beetle” sets off an alarm in our heads — we are all too familiar with the massive destruction caused by these tiny creatures.
The state is still feeling the devastating effects of the mountain pine beetle infestation, which reached epidemic levels in 2015, and now, another kind of beetle is arising as a threat to Colorado urban forests — the emerald ash borer.
According to the Colorado Department of Agriculture, the emerald ash borer is an invasive, wood-boring beetle originating from China and Eastern Asia, most likely brought to North America via wood packing materials used in shipping, and it specifically attacks ash trees.
Like the mountain pine beetle, the emerald ash borer lays its eggs under the bark. Once a tree is inhabited, the larvae strip the inner bark away, cutting off the flow of water and nutrients to the tree. The emerald ash borer is an aggressive insect that can kill a healthy tree within two to four years of infestation.
Unlike the mountain pine beetle, the emerald ash borer is not native to Colorado, nor is its target tree species. This is good news for the Vail Valley, as ash trees do not grow naturally in the mountains, but Colorado Department of Agriculture Phytosanitary Manager Laura Pottorff said the emerald ash borer has become a huge problem on the Front Range. Pottorff explained that the ash tree was originally introduced to Colorado because it was so sturdy and tough and did well at high elevations.
“This particular tree was widely available and a good choice for our harsh climate, and subsequently, we used it too much,” Pottorff said.
The ash, commonly found in the Midwest, currently makes up approximately 15 percent of trees in Colorado urban forests; the Colorado Department of Agriculture estimates there are around 98,000 ash trees in Boulder County alone and around 1.45 million in the Denver Metro area.
Pottorff warned, however, that though ash trees do not…