Cottonwood Digger Moth (Acronicta lepusculina)
A particularly large moth, found in most of eastern North America, west through southern Canada to Vancouver Island and southward. This specimen had just been attacked by a pair of Chipping Sparrows.
The wingspan is 40–50 mm. Adults are on wing from May to July depending on the location. The larvae feed on the leaves of Salix, Populus and Betula species.