Psyche casta is a nocturnal moth from the family Psychidae, the bagworm moths. The wingspan of the males ranges from 12 to 15 millimeters. They have hairy, brown-metallic shiny wings. The grub-like females have legs but do not have wings and are yellowish or light brown, except for some dark brown back plates.
The host plants are from the groups: Poaceae, birch, willow, poplar and Vaccinium. The caterpillars make a protective hull from grass.
The flight time ranges from May to July.
