Probable crambid lawn moth, Agriphila attenuata
Andrew Springer collected this moth in an office building in Wallace, Calaveras County, California.
I sent some images to Dr. Lynn Kimsey of the UC Bohart Museum of Entomology. She passed the images along to a couple of her lepidoptera experts, including Jeff Smith, the Curator of Lepidoptera.
Both experts agree that it is likely Agriphila attenuatus with the palpi broken off. These moths are flying now. “The coastal examples of this moth have whitish fore wings generously peppered with dark brown scales except for a longitudinal band slightly anteriad of the center of the fore wings that is nearly devoid of the dark brown scales. Specimens from around here are pale yellowish tan like the one in the photos and peppered with a very few to a moderate amount of light brown scales. The flight period is short: from about the last week of Sept. to third week of Oct. with most specimens (in Davis) collected during the first two weeks of Oct.”