This species is easily confused with other Bactra species. It can be distinguished from B.furfurana by the crescent-shaped discocellular mark and the absence of a basal patch on the forewing; unicolourous specimens can only be separated by examination of the genitalia.
Recorded in 31 (11.5%) of the 270 2km squares of Huntingdonshire.
Last recorded in August 2018
Recorded date range (Adult): 14 May to 17 September