Ancylosis undulatella
This moth is a minor pest of sugarbeets where the larvae feed on leaves, stems, and crowns. Sugarbeets are not grown commercially in my part of the state and probably not grown at all. It is possible that the larvae are feeding locally on beets typically grown for table use. Or they may be feeding on amaranth (Amaranthus spp.) which is a close relative of beets.
Ancylosis undulatella, the sugarbeet crown borer moth or sugarbeet crown borer, is a species of snout moth in the genus Ancylosis. It was described by James Brackenridge Clemens in 1860. It is found in North America, from Ontario and Michigan to Florida, west to California, north to Oregon and Idaho.