The male has a wingspan of about 30 mm with dark brown forewings with white apical and basal streaks meeting to make a "V" shape with another spot close to the costa.

Patterns on the moths are highly variable, ranging from whitish to grey to pale brown with the females slightly larger and less strongly marked.

[3] The adults fly at dusk in May and June[1] and the females broadcast the eggs, in a hovering flight, just above the vegetation.

They feed from July to April and when fully fed are 20 mm long with a shiny white body and brown head, prothoracic plate and pinacula.

[4] Previously placed in the genus Hepialus – from the Greek; hēpialos – meaning a fever, as in 'the fitful, alternating flight' of the moth.