The larvae feed on Acer species, including Acer glabrum and Acer grandidentatum.

Acer glabrum is plentiful in many parts of the Rocky Mountains, often growing with Ponderosa Pine, Douglas-fir, and Quaking Aspen.

Trees and shrubs in the arboretum include Acer glabrum, Acer negundo, Aesculus hippocastanum, Berberis thunbergii, Betula pendula var.

Acer glabrum is a species of maple native to western North America, from southeastern Alaska, British Columbia and western Alberta, east to western Nebraska, and south through Washington, Idaho, Montana and Colorado to California, Arizona and New Mexico.

Wolfe and Tanai note in the species description that the fossils are the first Tertiary record of an Acer glabrum (Douglas maple )-type fruit in western North America, and further note that no characters separate A. traini fruits from A. glabrum fruits.