This pest feeds on cottonwood leaves as both a larva and adult, skeletonizing leaves and causing chewing injuries. From a distance, this damage will appear as a general browning of the leaves. Upon closer inspection, the skeletonized leaves are easily seen.  Until 2021, damage in Colorado has primarily been located in the eastern half of the state, but recent warm winters have probably contributed to this insect’s migration into the mountains. 

PHOTO (left) accredited to: James Solomon, USDA Forest Service, www.Bugwood.org

PHOTO (middle) accredited to: Theodor D. Leininger, USDA Forest Service, www.Bugwood.org

PHOTO (right) accredited to: James Solomon, USDA Forest Service, www.Bugwood.org